ORCID Profile
0000-0001-9705-6913
Current Organisation
RMIT University
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Materials Engineering | Metals and Alloy Materials | Manufacturing Processes and Technologies (excl. Textiles) | Biomaterials | Physical Metallurgy | Alloy Materials | Aerospace Materials | Functional Materials | Additive manufacturing | Manufacturing engineering | Automotive Engineering Materials | Aerospace Engineering | Composite Materials | Nanoscale Characterisation | Metals and alloy materials | Nanomaterials | Aerospace structures | Innovation and Technology Management | Manufacturing Engineering | Nanotechnology | Pyrometallurgy | Composite and Hybrid Materials | Cell Development, Proliferation and Death
Structural Metal Products | Expanding Knowledge in Engineering | Basic Aluminium Products | Coated Metal and Metal-Coated Products | Structural metal products | Metals (composites, coatings, bonding, etc.) | Basic Metal Products (incl. Smelting, Rolling, Drawing and Extruding) not elsewhere classified | Education and Training Systems not elsewhere classified | Environmentally Sustainable Manufacturing not elsewhere classified | Chemical sciences | Physical sciences | Expanding Knowledge in the Medical and Health Sciences | Sheet metal products | Expanding Knowledge in Technology | Basic Iron and Steel Products | Defence not elsewhere classified | Metal Castings | Expanding Knowledge in the Chemical Sciences | Fabricated metal products not elsewhere classified | Expanding Knowledge in the Physical Sciences | Industrial Machinery and Equipment | Health not elsewhere classified |
Publisher: Japan Institute of Metals
Date: 10-2018
Publisher: Trans Tech Publications, Ltd.
Date: 04-2009
DOI: 10.4028/WWW.SCIENTIFIC.NET/MSF.618-619.621
Abstract: Electron beam (EB) direct manufacturing is an additive near-net shape digital fabrication process developed recently. The process offers a promising route for the fabrication of intricate speciality aluminium alloy parts for aircraft and aerospace applications because of the excellent energy coupling between an electron beam and aluminium. As part of a fundamental study on EB manufacturing of Al alloys, this work investigates the effect of the EB processing parameters on the development of the molten pool and the solidification characteristics of Al 2219 and Al 6061 alloys. The s les were processed using a 50kV electron beam gun over a wide range of beam currents (10-40mA) and welding speeds (0.3-0.86m/min) in both the static and oscillation focus modes. In the static focus mode, the molten pool is wedge-shaped while in the oscillation focus mode, the molten pool is hemispherical, wider and shallower. In both cases, the depth and width of the molten pool increase with increasing beam current but they are less affected by the moving speed of the EB gun in the range 0.3-0.86m/min. Electron beam re-melted and subsequently re-solidified Al 2219 and Al 6061 alloys show microstructural features distinct from those obtained under sand casting and direct chill casting conditions. In particular, fine intermetallic precipitates in the size range 100-200nm are prominent in the equiaxed grains formed in the re-solidified weld beads of Al 6061 compared to the coarse intermetallic particles up to 10m in size prior to EB processing. EB processing offers opportunities for aluminium alloy development.
Publisher: Elsevier BV
Date: 09-2021
Publisher: Wiley
Date: 02-2018
Publisher: Elsevier BV
Date: 10-2018
Publisher: Elsevier BV
Date: 07-2013
Publisher: Trans Tech Publications, Ltd.
Date: 04-2009
DOI: 10.4028/WWW.SCIENTIFIC.NET/MSF.618-619.509
Abstract: The liquid-phase sintering of Ti-Si binary alloys using mixed elemental powders has been explored. Sintering at low liquid contents avoids excessive porosity and bulging of compacts, and leads to development of a densified surface. Compacts made in this way can be HIPped without a container to full or near full densities. Exploiting the surface densification phenomenon may enable cost-effective net shape manufacturing of full density titanium components.
Publisher: Elsevier BV
Date: 05-2016
Publisher: Elsevier BV
Date: 2013
Publisher: Elsevier BV
Date: 06-2019
Publisher: Maney Publishing
Date: 06-2007
Publisher: Elsevier BV
Date: 12-2013
DOI: 10.1016/J.JMBBM.2013.08.013
Abstract: The application of titanium (Ti) based biomedical materials which are widely used at present, such as commercially pure titanium (CP-Ti) and Ti-6Al-4V, are limited by the mismatch of Young's modulus between the implant and the bones, the high costs of products, and the difficulty of producing complex shapes of materials by conventional methods. Niobium (Nb) is a non-toxic element with strong β stabilizing effect in Ti alloys, which makes Ti-Nb based alloys attractive for implant application. Metal injection molding (MIM) is a cost-efficient near-net shape process. Thus, it attracts growing interest for the processing of Ti and Ti alloys as biomaterial. In this investigation, metal injection molding was applied to the fabrication of a series of Ti-Nb binary alloys with niobium content ranging from 10wt% to 22wt%, and CP-Ti for comparison. Specimens were characterized by melt extraction, optical microscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), and transmission electron microscopy (TEM). Titanium carbide formation was observed in all the as-sintered Ti-Nb binary alloys but not in the as-sintered CP-Ti. Selected area electron diffraction (SAED) patterns revealed that the carbides are Ti2C. It was found that with increasing niobium content from 0% to 22%, the porosity increased from about 1.6% to 5.8%, and the carbide area fraction increased from 0% to about 1.8% in the as-sintered s les. The effects of niobium content, porosity and titanium carbides on mechanical properties have been discussed. The as-sintered Ti-Nb specimens exhibited an excellent combination of high tensile strength and low Young's modulus, but relatively low ductility.
Publisher: Springer Science and Business Media LLC
Date: 30-05-2012
Publisher: Springer Science and Business Media LLC
Date: 12-10-2021
Publisher: Elsevier BV
Date: 02-2023
Publisher: MDPI AG
Date: 09-2018
DOI: 10.3390/MA11091573
Abstract: Biocompatible titanium scaffolds with up to 40% interconnected porosity were manufactured through the metal injection moulding process and the space holder technique. The mechanical properties of the manufactured scaffold showed a high level of compatibility with those of the cortical human bone. Sintering at 1250 °C produced scaffolds with 36% porosity and more than 90% interconnected pores, a compressive yield stress of 220 MPa and a Young’s modulus of 7.80 GPa, all suitable for bone tissue engineering. Increasing the sintering temperature to 1300 °C increased the Young’s modulus to 22.0 GPa due to reduced porosity, while reducing the sintering temperature to 1150 °C lowered the yield stress to 120 MPa, indicative of insufficient sintering. Electrochemical studies revealed that s les sintered at 1150 °C have a higher corrosion rate compared with those at a sintering temperature of 1250 °C. Overall, it was concluded that sintering at 1250 °C yielded the most desirable results.
Publisher: Elsevier BV
Date: 09-2020
Publisher: Elsevier BV
Date: 06-2023
Publisher: Springer Science and Business Media LLC
Date: 10-2016
DOI: 10.1557/MRS.2016.215
Publisher: Elsevier BV
Date: 2013
Publisher: Elsevier BV
Date: 03-2020
Publisher: Trans Tech Publications, Ltd.
Date: 06-2010
DOI: 10.4028/WWW.SCIENTIFIC.NET/MSF.654-656.1054
Abstract: Gas-atomized Cu-based metallic glass powder was heat-treated in air from below its glass transition temperature (Tg) to well above its crystallization temperature (Tx). Severe oxidation occurred at temperatures Tx while at temperatures Tg oxidation was sluggish. The oxidation products were determined and the mechanism is discussed based on the microstructural findings.
Publisher: Elsevier BV
Date: 04-2014
Publisher: Trans Tech Publications, Ltd.
Date: 04-2009
DOI: 10.4028/WWW.SCIENTIFIC.NET/MSF.618-619.631
Abstract: A TEM study of aluminium nitride formed during sintering of powder injection moulded aluminium under nitrogen is presented. A polycrystalline layer consisting of fine, rod-shaped crystallites of hexagonal AlN formed on the Al powder surfaces. The grain boundaries exhibit a double layer of AlN separated by a thin layer of Al. The structure of the AlN is characterised and its influence upon sintering discussed.
Publisher: Springer Science and Business Media LLC
Date: 19-02-2022
DOI: 10.1007/S40964-021-00259-2
Abstract: High strength aluminum alloys, especially those that are age-hardenable, such as 2xxx series, 6xxx series, and 7xxx series, are widely used as structural materials in transport and aerospace industries due to their good mechanical properties. However, additive manufacturing of high strength aluminum alloys is challenging due to their susceptibility to hot tearing. In this work, a systematic study has been conducted in an attempt to eliminate hot tearing in laser powder bed fusion (PBF-LB/M) manufacturing of Al2139 alloy through selecting process parameters and the addition of an AlTiB grain refiner. It was found that hot tearing in Al2139 during PBF-LB/M can be reduced or eliminated by increasing volumetric energy density. Furthermore, grain refinement by AlTiB addition shows a clear effect in reducing hot tearing, even though the refined grains remain predominantly columnar rather than equiaxed. The effect of increasing volumetric energy density on hot tearing of Al2139 during PBF-LB/M was analyzed by thermomechanical finite-element simulation, which showed that the reduction in hot tearing with increasing energy density is associated with a decrease in the thermal residual stress. However, it was also shown that there can be a substantive loss of Mg due to evaporation at high energy densities. From a hot tearing model based on solidification thermodynamics, the loss of Mg on hot tearing in Al2139 was estimated to reduce hot tearing by up to 10%, compared to the initial powder composition. With the selected PBF-LB/M parameters, crack-free tensile specimens were fabricated, with and without the addition of AlTiB. Compared with their wrought or cast counterparts, the PBF-LB/M Al2139 and Al2139-AlTiB specimens show lower yield strength but better ductility, which can be attributed to the loss of Mg during PBF-LB/M.
Publisher: Elsevier BV
Date: 12-1996
Publisher: Springer Science and Business Media LLC
Date: 06-07-2012
Publisher: Springer Science and Business Media LLC
Date: 08-11-2012
Publisher: Springer Science and Business Media LLC
Date: 08-10-2019
Publisher: Elsevier BV
Date: 03-2020
Publisher: Wiley
Date: 17-04-2018
DOI: 10.1002/JBM.A.36402
Abstract: The surface of an orthopaedic implant plays a crucial role in determining the adsorption of proteins and cell functions. A detailed comparative study has been made of the in vitro osteoblast responses to coarse-grained (grain size: 500 μm), ultrafine-grained (grain size: 100 nm), coarse-porous (pore size: 350 nm), and fine-porous (pore size: 155 nm) surfaces of Ti-20Mo alloy. The purpose was to provide essential experimental data for future design of orthopaedic titanium implants for rapid osseointegration. Systematic original experimental data was produced for each type of surfaces in terms of surface wettability, cell morphology, adhesion, growth, and differentiation. Microscopic evidence was collected to reveal the detailed interplay between each characteristic surface with proteins or cells. Various new observations were discussed and compared with literature data. It was concluded that the coarse-porous surfaces offered the optimum topographical environment for osteoblasts and that the combination of ultrafine grains and considerable grain boundary areas is not an effective way to enhance cell growth and osteogenic capacity. Moreover, pore features (size and depth) have a greater effect than smooth surfaces on cell growth and osteogenic capacity. It proves that cells can discern the difference in pore size in the range of 100-350 nm. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 2020-2033, 2018.
Publisher: Springer Science and Business Media LLC
Date: 29-08-2019
Publisher: Informa UK Limited
Date: 04-2002
Publisher: Elsevier BV
Date: 04-2007
Publisher: Elsevier BV
Date: 10-2022
Publisher: Informa UK Limited
Date: 26-05-2016
Publisher: Informa UK Limited
Date: 04-2002
Publisher: Trans Tech Publications, Ltd.
Date: 04-2009
DOI: 10.4028/WWW.SCIENTIFIC.NET/MSF.618-619.635
Abstract: An investigation has been made on the infiltration behaviour in rapid prototyping of Al alloy parts under different infiltration atmospheres. An Al 6061 alloy preform was first prepared by selective laser sintering. Then the aluminium precursor powders in the preform were converted into AlN to form a skeletal AlN structure, which was subsequently pressureless infiltrated with a molten Al 6061 alloy under nitrogen, argon or vacuum. The pathway of the infiltrant was determined by density measurements in conjunction with metallographic examination and quantitative image analysis. Detailed comparison of the microstructures at the surface and the centre of the as-infiltrated s les indicates that the pathway into the porous preform is dependent on the infiltration atmosphere. Under vacuum, the infiltrant fills the interior of the preform first and then propagates to the surface. In contrast, under nitrogen or argon, the infiltrant penetrates along the surface prior to filling the interior.
Publisher: Elsevier BV
Date: 04-2013
Publisher: Wiley
Date: 22-06-2018
Publisher: Springer International Publishing
Date: 2019
Publisher: Springer Science and Business Media LLC
Date: 07-10-2022
DOI: 10.1038/S41467-022-33482-8
Abstract: Solidification processing is essential to the manufacture of various metal products, including additive manufacturing. Solidification grain boundaries (SGBs) result from the solidification of the last liquid film between two abutting grains of different orientations. They can migrate, but unlike normal GB migration, SGB migration (SGBM) decouples SGBs from solidification microsegregation, further affecting material properties. Here, we first show the salient features of SGBM in magnesium-tin alloys solidified with cooling rates of 8−1690 °C/s. A theoretical model is then developed for SGBM in dilute binary alloys, focusing on the effect of solute type and content, and applied to 10 alloy systems with remarkable agreement. SGMB does not depend on cooling rate or time but relates to grain size. It tends to occur athermally. The findings of this study extend perspectives on solidification grain structure formation and control for improved performance (e.g. hot or liquation cracking during reheating, intergranular corrosion or fracture).
Publisher: The Materials Research Society of Korea
Date: 04-2013
Publisher: Springer Science and Business Media LLC
Date: 29-08-2017
DOI: 10.1038/S41598-017-10354-6
Abstract: The present study investigates the influence of ultrasonic treatment on the grain refinement of commercial purity aluminium with a range of Al3Ti1B master alloy additions. When the aluminium contains the smallest amount of added master alloy, ultrasonics caused significant additional grain refinement compared to that provided by the master alloy alone. However, the influence of ultrasonics on grain size reduces with increasing addition of the master alloy which adds additional TiB 2 particles and Ti solute with each incremental addition. Applying the Interdependence model to analyse the experimentally measured grain sizes revealed that the results of this study and those from similar experiments on an Al-2Cu alloy were consistent when the alloy compositions are converted to their growth restriction factors ( Q) and that increasing Q had a major effect on reducing grain size and increasing grain number density. Compared with the application of ultrasonic treatment where an order of magnitude increase in the grain number density is achieved, an increase in the Ti content over the range of master alloy additions, causes the grain number density to increase by approximately three times.
Publisher: Springer Science and Business Media LLC
Date: 02-11-2020
Publisher: Elsevier BV
Date: 12-2011
Publisher: Elsevier BV
Date: 11-2011
Publisher: Maney Publishing
Date: 08-2009
Publisher: Springer Science and Business Media LLC
Date: 27-11-2017
Publisher: Springer Science and Business Media LLC
Date: 28-08-2015
Publisher: Elsevier BV
Date: 12-2013
Publisher: Elsevier BV
Date: 02-1996
Publisher: Elsevier BV
Date: 09-2013
Publisher: Springer Science and Business Media LLC
Date: 04-02-2015
Publisher: Trans Tech Publications, Ltd.
Date: 06-2011
DOI: 10.4028/WWW.SCIENTIFIC.NET/MSF.690.206
Abstract: The Interdependence Theory is a theoretical description of grain formation that links heterogeneous nucleation to grain growth early in the initial transient of a previously nucleated grain. Thus nucleation is the result of a repeating cycle of growth and nucleation events moving towards the thermal centre of a casting. The principles of this theory are introduced and then the Interdependence equation that embodies the Interdependence Theory, is applied to the prediction of experimental grain size data for aluminium, magnesium and titanium-based alloy systems.
Publisher: Elsevier BV
Date: 10-2010
Publisher: Elsevier BV
Date: 02-2016
Publisher: Springer Science and Business Media LLC
Date: 12-07-2018
Publisher: Elsevier BV
Date: 05-2016
Publisher: Elsevier BV
Date: 10-2006
Publisher: Informa UK Limited
Date: 08-03-2022
Publisher: Elsevier
Date: 2015
Publisher: Elsevier BV
Date: 08-2020
Publisher: Elsevier BV
Date: 03-2016
DOI: 10.1016/J.BIOMATERIALS.2016.01.012
Abstract: One of the critical issues in orthopaedic regenerative medicine is the design of bone scaffolds and implants that replicate the biomechanical properties of the host bones. Porous metals have found themselves to be suitable candidates for repairing or replacing the damaged bones since their stiffness and porosity can be adjusted on demands. Another advantage of porous metals lies in their open space for the in-growth of bone tissue, hence accelerating the osseointegration process. The fabrication of porous metals has been extensively explored over decades, however only limited controls over the internal architecture can be achieved by the conventional processes. Recent advances in additive manufacturing have provided unprecedented opportunities for producing complex structures to meet the increasing demands for implants with customized mechanical performance. At the same time, topology optimization techniques have been developed to enable the internal architecture of porous metals to be designed to achieve specified mechanical properties at will. Thus implants designed via the topology optimization approach and produced by additive manufacturing are of great interest. This paper reviews the state-of-the-art of topological design and manufacturing processes of various types of porous metals, in particular for titanium alloys, biodegradable metals and shape memory alloys. This review also identifies the limitations of current techniques and addresses the directions for future investigations.
Publisher: Elsevier
Date: 2018
Publisher: Elsevier BV
Date: 08-2013
Publisher: Elsevier BV
Date: 2013
Publisher: Elsevier BV
Date: 04-2004
Publisher: Elsevier BV
Date: 11-2020
Publisher: Trans Tech Publications, Ltd.
Date: 08-2016
DOI: 10.4028/WWW.SCIENTIFIC.NET/KEM.704.388
Abstract: Powder metallurgy (PM) of titanium hydride (TiH 2 ) has emerged as an attractive alternative to PM of Ti. Microwave (MW) heating has the potential to further facilitate the development of PM TiH 2 as TiH 2 is essentially a ceramic material. A detailed assessment has been made of the effectiveness of MW heating of Ti- x TiH 2 ( x =0-100) powder compacts through 30 experiments conducted under a variety of conditions. MW hybrid heating (i.e. when assisted with a SiC MW susceptor) proved to be reliable and consistent in heating Ti- x TiH 2 powder compacts and the heating rate increased progressively with increasing TiH 2 powder content, indicating that TiH 2 powder is more responsive to MW heating than Ti metal powder. However, heating of TiH 2 powder compacts by MW radiation without the assistance of a SiC MW susceptor proved to be inconsistent and unpredictable, where successful heating (heated to 1300°C in 20 min) was achieved but many failures also occurred. However, the use of SiC can cause contamination (Si and C). The challenges of heating of TiH 2 powder by direct MW radiation were discussed.
Publisher: Elsevier BV
Date: 04-2022
Publisher: Informa UK Limited
Date: 05-2004
Publisher: Elsevier BV
Date: 11-2018
Publisher: Elsevier BV
Date: 05-2017
Publisher: Elsevier BV
Date: 09-2021
Publisher: Elsevier
Date: 2019
Publisher: Elsevier BV
Date: 09-2017
Publisher: Springer Science and Business Media LLC
Date: 20-05-2015
Publisher: Springer Science and Business Media LLC
Date: 26-10-2017
Publisher: Japan Institute of Metals
Date: 2005
Publisher: Springer Science and Business Media LLC
Date: 22-02-2017
Publisher: Elsevier BV
Date: 08-2014
Publisher: Springer Science and Business Media LLC
Date: 04-01-2016
Publisher: Elsevier BV
Date: 09-2017
Publisher: Elsevier BV
Date: 11-2023
Publisher: Trans Tech Publications, Ltd.
Date: 08-2012
DOI: 10.4028/WWW.SCIENTIFIC.NET/KEM.520.89
Abstract: TiAl alloy powder is difficult to sinter unless assisted with pressure and/or pulsed current. This paper investigates the effect of a small addition of iron on the sintering behaviour of γ-TiAl alloy powder at 1350 °C in vacuum. Thermodynamic calculations using Thermo-Calc and the Ti-alloy database TTTI3 predict that iron is a potential sintering aid for TiAl powder. The relative sintered density (RSD) increased with increasing Fe content and peaked at an addition of 2at.%Fe, at which the RSD increased from ~ 60% theoretical density (TD) without iron to ~ 97%TD. The enhanced densification is attributed to liquid formation induced by iron based on both thermodynamic predictions and differential scanning calorimetry (DSC) analysis. The as-sintered microstructures and phase constituents were analysed by scanning electron microscopy (SEM) equipped with an energy dispersive spectroscopy (EDS) microanalysis system and X-ray diffraction (XRD) analysis.
Publisher: Springer Science and Business Media LLC
Date: 20-05-2019
Publisher: Elsevier BV
Date: 05-2006
Publisher: Elsevier BV
Date: 02-2014
DOI: 10.1016/J.ACTBIO.2013.10.034
Abstract: The formation of grain boundary (GB) brittle carbides with a complex three-dimensional (3-D) morphology can be detrimental to both the fatigue properties and corrosion resistance of a biomedical titanium alloy. A detailed microscopic study has been performed on an as-sintered biomedical Ti-15Mo (in wt.%) alloy containing 0.032 wt.% C. A noticeable presence of a carbon-enriched phase has been observed along the GB, although the carbon content is well below the maximum carbon limit of 0.1 wt.% specified by ASTM Standard F2066. Transmission electron microscopy (TEM) identified that the carbon-enriched phase is face-centred cubic Ti2C. 3-D tomography reconstruction revealed that the Ti2C structure has morphology similar to primary α-Ti. Nanoindentation confirmed the high hardness and high Young's modulus of the GB Ti2C phase. To avoid GB carbide formation in Ti-15Mo, the carbon content should be limited to 0.006 wt.% by Thermo-Calc predictions. Similar analyses and characterization of the carbide formation in biomedical unalloyed Ti, Ti-6Al-4V and Ti-16Nb have also been performed.
Publisher: Elsevier BV
Date: 10-2021
Publisher: Elsevier BV
Date: 12-2017
Publisher: MDPI AG
Date: 26-12-2018
DOI: 10.3390/MA12010073
Abstract: The influences of processing parameters such as volumetric energy density (ε) and, particularly, defocusing amount (DA) on densification, microstructure, tensile property, and hardness of the as-printed dense AlSi10Mg alloy by selective laser melting (SLM) were studied systematically. The molten pool boundaries (MPBs) were found overwhelmingly at regular and complex spatial topological structures affected by DA value to exist in two forms, while the “layer–layer” MPB overlay mutually and the “track–track” MPBs intersect to form acute angles with each other. The microstructure of MPBs exhibits a coarse grain zone near the MPBs and the characteristics of segregation of nonmetallic elements (O, Si) where the crack easily happened. The DA value (−2 to 2 mm) affected both the density and the tensile mechanical properties. High tensile strength (456 ± 14 MPa) and good tensile ductility (9.5 ± 1.4%) were achieved in the as-printed condition corresponding to DA = 0.5 mm. The tensile fracture surface features were analyzed and correlated to the influence of the DA values.
Publisher: Elsevier BV
Date: 03-2010
Publisher: Springer Science and Business Media LLC
Date: 19-06-2019
Publisher: Elsevier BV
Date: 03-2020
Publisher: Elsevier BV
Date: 06-2019
Publisher: Elsevier
Date: 2019
Publisher: Springer Science and Business Media LLC
Date: 30-10-2015
Publisher: Informa UK Limited
Date: 2013
DOI: 10.1080/08327823.2013.11689842
Abstract: Accurate temperature measurement remains a challenge for microwave heating of powder materials. We propose a temperature calibration method based on exothermic reactions and the resultant thermal runaway that occurs during microwave heating. The approach was demonstrated on microwave heating of four titanium alloys. Differential scanning calorimetry was used to determine the threshold reaction temperature for each selected titanium alloy. This served as a standard for the microwave heating of these titanium alloys. Infrared pyrometric temperature measurements were then calibrated by comparing the starting temperature of each thermal runaway event with the threshold reaction temperature.
Publisher: Springer Science and Business Media LLC
Date: 09-01-2020
DOI: 10.1038/S41467-019-13874-Z
Abstract: Additive manufacturing (AM) of metals, also known as metal 3D printing, typically leads to the formation of columnar grain structures along the build direction in most as-built metals and alloys. These long columnar grains can cause property anisotropy, which is usually detrimental to component qualification or targeted applications. Here, without changing alloy chemistry, we demonstrate an AM solidification-control solution to printing metallic alloys with an equiaxed grain structure and improved mechanical properties. Using the titanium alloy Ti-6Al-4V as a model alloy, we employ high-intensity ultrasound to achieve full transition from columnar grains to fine (~100 µm) equiaxed grains in AM Ti-6Al-4V s les by laser powder deposition. This results in a 12% improvement in both the yield stress and tensile strength compared with the conventional AM columnar Ti-6Al-4V. We further demonstrate the generality of our technique by achieving similar grain structure control results in the nickel-based superalloy Inconel 625, and expect that this method may be applicable to other metallic materials that exhibit columnar grain structures during AM.
Publisher: Elsevier BV
Date: 06-2021
Publisher: Elsevier
Date: 2018
Publisher: Springer Science and Business Media LLC
Date: 11-09-2019
Publisher: Springer Science and Business Media LLC
Date: 16-05-2012
DOI: 10.1557/JMR.2012.140
Publisher: Elsevier BV
Date: 10-1998
Publisher: Elsevier BV
Date: 06-2005
Publisher: Springer Science and Business Media LLC
Date: 03-10-2018
Publisher: Elsevier BV
Date: 2024
Publisher: Elsevier BV
Date: 07-2010
Publisher: Springer Science and Business Media LLC
Date: 07-1995
DOI: 10.1007/BF00349883
Publisher: Elsevier BV
Date: 09-2019
Publisher: Elsevier BV
Date: 12-2017
Publisher: Elsevier BV
Date: 12-2019
Publisher: Elsevier BV
Date: 10-2022
Publisher: Springer Science and Business Media LLC
Date: 05-2022
DOI: 10.1007/S10704-022-00641-3
Abstract: Fatigue and crack growth characteristics are essential cyclic properties of additively manufactured (AM) components for load-bearing applications, which are less reported in the literature than static properties. The fatigue behaviour of AM components is more complicated than those produced by conventional fabrication techniques (casting and forging) because of the multiplicity of different influencing factors like defect distribution, inhomogeneity of the microstructure and consequent anisotropy. Therefore, it is crucial to understand fatigue performance under different loading conditions to enhance AM application in aerospace, automotive, and other industries. The present work summarises the published literature for fatigue properties of popular metals (Ti–6Al–4V, Al–Si–Mg and stainless steels) produced by the laser powder-bed-fusion (L-PBF) process. Moreover, process parameters, post-processing treatments and microstructures of these alloys are discussed to evaluate the current state-of-the-art of fatigue and crack growth properties of L-PBF metals. The static properties of these alloys are also included to incorporate only those cases for which fatigue behaviour are discussed later in this review to make a correlation between the static and fatigue properties for these alloys. The effects of build orientation, microstructure, heat treatment, surface roughness and defects on fatigue strength and fatigue crack growth threshold are observed and critically analysed based on available literature. This study also highlights the common and contrary findings in the literature associated with various influential factors to comprehensively understand the cyclic loading behaviour of L-PBF produced metal alloys.
Publisher: Springer Science and Business Media LLC
Date: 04-2002
Publisher: Springer Science and Business Media LLC
Date: 06-01-2016
Publisher: Elsevier BV
Date: 12-2023
Publisher: Springer Science and Business Media LLC
Date: 12-2000
Publisher: Elsevier BV
Date: 1997
Publisher: Informa UK Limited
Date: 12-01-2017
Publisher: Elsevier BV
Date: 05-1999
Publisher: Elsevier BV
Date: 08-2014
Publisher: Trans Tech Publications, Ltd.
Date: 08-2012
DOI: 10.4028/WWW.SCIENTIFIC.NET/KEM.520.24
Abstract: The inexpensive hydrogenated–dehydrogenated (HDH) titanium powder made from the Kroll sponge titanium provides a cost-affordable basis for powder metallurgy (PM) Ti alloy development. The design targets we hope to achieve are low feedstock cost ( $25/kg) including all alloying elements low fabrication cost based on cold compaction and pressureless sintering, and wrought grades of properties of Ti-6Al-4V in the as-sintered state. Relevant issues are considered. These include alloying with inexpensive elements such as Fe and Si, grain size control during heating, isothermal sintering and cooling, chemical homogeneity of as-sintered microstructure, and simultaneous scavenging of oxygen and chlorine. In addition, it is proposed that achieving 6% of tensile elongation will be adequate for most PM Ti applications, compared to PM steels (normally 2%), PM aluminium alloys (mostly 4%) and the requirements for wrought Ti-6Al-4V armour plates (≥ 6%). This will allow the use of HDH Ti powder that contains relatively high oxygen (~0.35wt.%) and direct more efforts towards improving other properties.
Publisher: Elsevier BV
Date: 02-2020
Publisher: Springer Science and Business Media LLC
Date: 03-2012
Publisher: Trans Tech Publications, Ltd.
Date: 05-2010
DOI: 10.4028/WWW.SCIENTIFIC.NET/KEM.436.141
Abstract: Effective sintering of titanium requires the use of a high sintering temperature (≥1200 °C), preferably in high vacuum ( 10-2 Pa). This confines the heating and cooling rates to ~ 4 °C/min because of the limited thermal shock resistance of ceramic tube furnaces. Consequently, it leads to lengthy sintering cycles (10-12 hr). This work presents an assessment of microwave (MW) sintering of titanium. Titanium powders in the size ranges of µm, 45-63 µm, and 100-150 µm were used to make green s les with compaction pressures ranging from 200-800 MPa. Sintering was carried out at 1200 °C for 2 hr in a 3 kW MW furnace with a 2.45 GHz multimode cavity under a vacuum of 2-6×10-3 Pa. The characteristics of MW heating of green titanium s les in vacuum are described in terms of the heating rate, vacuum fluctuations, and sparking discharge. The actual MW heating rate achieved from 350 °C to 1200 °C was 34 °C/min. The attendant densities are comparable to those attained by conventional vacuum sintering. Cross-sectional examinations revealed a fairly uniform pore distribution in MW-sintered s les made from either the coarse or fine titanium powder.
Publisher: American Chemical Society (ACS)
Date: 06-05-2019
Abstract: Statistical data have consistently shown that implant loosening is a significant causative factor for revision surgeries. Both
Publisher: Springer Science and Business Media LLC
Date: 20-07-2017
Publisher: Elsevier BV
Date: 04-2017
Publisher: Elsevier BV
Date: 09-2022
Publisher: Elsevier BV
Date: 07-2011
Publisher: Springer Science and Business Media LLC
Date: 10-2000
Publisher: Elsevier BV
Date: 06-2023
Publisher: Springer Science and Business Media LLC
Date: 16-03-2018
Publisher: Elsevier BV
Date: 12-2018
DOI: 10.1016/J.JMBBM.2018.08.038
Abstract: A biocompatible Ti-12Mo alloy was fabricated by metal injection moulding (MIM) using non-spherical titanium, molybdenum powders and a purposely designed binder. The density, microstructure and tensile properties were characterized. This was followed by a detailed assessment of its in vitro corrosion and biocompatibility performances, compared with that of two commonly used titanium-based materials extra low interstitial (ELI) Ti-6Al-4V and commercially pure (CP) titanium. The MIM-fabricated Ti-12Mo alloy can achieve a wide range of mechanical properties through controlling sintering process. Specimens sintered at 1400 °C are characterized by fairly uniform near-β microstructure and high relative density of 97.6%, leading to the highest tensile strength of 845.3 ± 21 MPa and elongation of 4.15 ± 0.2% while the highest elastic modulus of 73.2 ± 5.1 GPa. Owing to the formation of protective TiO
Publisher: Springer Science and Business Media LLC
Date: 16-07-2018
Publisher: Elsevier BV
Date: 07-2009
Publisher: Springer Science and Business Media LLC
Date: 10-03-2017
Publisher: Elsevier BV
Date: 04-2023
Publisher: Elsevier BV
Date: 09-2018
Publisher: Elsevier BV
Date: 02-2018
Publisher: Elsevier BV
Date: 2022
DOI: 10.1016/J.BIOMATERIALS.2021.121271
Abstract: Conventional copper (Cu) metal surfaces are well recognized for their bactericidal properties. However, their slow bacteria-killing potency has historically excluded them as a rapid bactericidal material. We report the development of a robust bulk superhydrophilic micro-nano hierarchical Cu structure that possesses exceptional bactericidal efficacy. It resulted in a 4.41 log
Publisher: Springer Science and Business Media LLC
Date: 26-03-2011
Publisher: The Electrochemical Society
Date: 27-07-2015
Abstract: This paper reports on the electrochemical dealloying of a ternary Al 67 Cu 18 Sn 15 (in at.% throughout the paper) alloy consisting of a-Al, Al 2 Cu and Sn using potentiodynamic and potentiostatic polarization measurements. When the applied potential (-0.5 V) was below the critical potential of the Al 2 Cu phase (-0.41 V), complete electrochemical dealloying of the binary Al 75 Cu 25 alloy (consisting of a-Al and Al 2 Cu) occurred, leading to the formation of a nanoporous (52 ± 10 nm) copper (Cu) structure. However, under the same condition dealloying only occurred partially to the α-Al phase in the ternary Al 67 Cu 18 Sn 15 alloy due to the suppressing influence of Sn. The electrochemical dealloying of the ternary Al 67 Cu 18 Sn 15 alloy was potential dependent and involved the concurrence of dealloying and realloying as evidenced by the formation of Cu 6 Sn 5 .
Publisher: Maney Publishing
Date: 08-2009
Publisher: Elsevier BV
Date: 2021
Publisher: Springer Science and Business Media LLC
Date: 12-2014
DOI: 10.1557/MRC.2014.33
Publisher: Informa UK Limited
Date: 06-2010
Publisher: Elsevier BV
Date: 08-2001
Publisher: Informa UK Limited
Date: 10-07-2015
Publisher: Springer Science and Business Media LLC
Date: 14-07-2011
DOI: 10.1557/JMR.2011.143
Publisher: Springer Science and Business Media LLC
Date: 13-11-2012
Publisher: Oxford University Press (OUP)
Date: 03-2023
DOI: 10.1093/PNASNEXUS/PGAD075
Abstract: Post-yield softening (PYS) plays an important role in guiding the design of high-performance energy-absorbing lattice materials. PYS is usually restricted to lattice materials that are stretching dominated according to the Gibson–Ashby model. Contrary to this long-held assumption, this work shows that PYS can also occur in various bending-dominated Ti-6Al-4V lattices with increasing relative density. The underlying mechanism for this unusual property is elucidated using the Timoshenko beam theory. It is attributed to the increase in stretching and shear deformation with increasing relative density, thereby increasing the tendency towards PYS. The finding of this work extends perspectives on PYS for the design of high-performance energy-absorbing lattice materials.
Publisher: Informa UK Limited
Date: 07-08-2014
Publisher: Elsevier BV
Date: 09-2023
Publisher: Trans Tech Publications, Ltd.
Date: 04-2009
DOI: 10.4028/WWW.SCIENTIFIC.NET/MSF.618-619.617
Abstract: Recent breakthroughs in the sintering of aluminium alloys under nitrogen have opened the way for the in-situ fabrication of Al-AlN composites in a controllable and reproducible fashion over a wide range of volume fractions of AlN. This work reviews the fundamentals for the in-situ fabrication of the Al-AlN composites from metal powders and highlights their technical potential for niche applications because of their excellent resistance to cavitation erosion in water and their unusually low friction coefficient under oil lubrication.
Publisher: Elsevier BV
Date: 06-2020
Publisher: Elsevier BV
Date: 03-0003
Publisher: Springer Science and Business Media LLC
Date: 19-01-2016
Publisher: Springer Science and Business Media LLC
Date: 10-04-2013
Publisher: Elsevier BV
Date: 05-2023
Publisher: Elsevier BV
Date: 06-2015
Publisher: Elsevier BV
Date: 02-2007
Publisher: Elsevier BV
Date: 08-2001
Publisher: Trans Tech Publications, Ltd.
Date: 07-2013
DOI: 10.4028/WWW.SCIENTIFIC.NET/MSF.765.123
Abstract: The development of grain refinement technologies began in the 1930s in response to the need to improve the mechanical properties of as-cast components. Commercial grain refining technologies were developed by industrial and experimental trials often with good success including the production of effective master alloys. In parallel, researchers developed theories to explain the mechanisms of refinement in order to improve the efficiency of refiners and develop new better performing grain refining master alloys. This research continues today. Here we briefly present the history of these developments. It is shown that many developments in our understanding were based on assumptions arising from experimental and industrial observations and the prevailing solidification theories of the time.
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C6AY01221C
Abstract: This article reviews the progress in the development of electrochemical nucleic acid biosensors with an emphasis on biosensor fabrication, the sensing mechanism, performance and applications with some discussion on challenges and perspectives.
Publisher: AIP Publishing
Date: 2009
DOI: 10.1063/1.3054374
Abstract: Few experimental data are available on ultrasonic attenuation in molten light alloys due to lack of means of characterization. An approach has been proposed and demonstrated to assessing ultrasonic attenuation in molten magnesium alloys based on the finding that the grain density in ultrasonicated magnesium alloy s les depends linearly on ultrasonic litude along the propagation direction. Hence, the attenuation of the ultrasonic litude with propagation distance can be effectively assessed according to the variations in the grain density with propagation distance. Metallographic analyses revealed that the dependence of grain density on propagation distance is best described exponentially with respect to different litudes. Consequently, the attenuation behavior of the ultrasonic litude with propagation distance can be described by the same exponential law. The characteristic ultrasonic attenuation coefficients in three benchmark molten magnesium alloys investigated were determined accordingly. The validation experiments confirmed the validity of the data produced. Ultrasonic attenuation shows dependence on alloy chemistry.
Publisher: Research Square Platform LLC
Date: 09-2022
DOI: 10.21203/RS.3.RS-1976866/V1
Abstract: Additive manufacturing (AM) technologies such as laser-based powder bed fusion (LB-PBF) facilitate the fabrication of complex lattice structures. However, these structures consistently display dimensional variation between the idealised and as-manufactured specimens. This research proposes a method to characterise the impact of common LB-PBF powders (aluminium and titanium alloys) and geometric design parameters (polygon order, effective diameter and inclination angle) on section properties relevant to stiffness and strength of as-manufactured strut elements will be quantified. Micro-computed tomography (µCT) will be applied to algorithmically characterise the as-manufactured variation and identify a scale threshold below which additional geometric resolution does not influence the section properties of as-manufactured parts. This methodology provides a robust and algorithmic, design for additive manufacturing (DFAM) tool to characterise the effects of manufacturing and design parameters on the functional response of AM strut elements, as is required for certification and optimisation.
Publisher: Elsevier BV
Date: 11-1999
Publisher: Springer Science and Business Media LLC
Date: 30-05-2012
Publisher: Elsevier BV
Date: 03-2023
Publisher: Springer Science and Business Media LLC
Date: 22-01-2020
Publisher: Springer Science and Business Media LLC
Date: 31-10-2019
Publisher: Elsevier BV
Date: 12-2022
Publisher: Informa UK Limited
Date: 20-10-2021
Publisher: Elsevier BV
Date: 06-2018
Publisher: Springer Science and Business Media LLC
Date: 06-2002
Publisher: Springer Science and Business Media LLC
Date: 03-02-2023
DOI: 10.1007/S00170-023-10865-9
Abstract: Surface roughness is traditionally evaluated with contact profilometry however, these methods are not compatible with complex additive manufactured lattice structures due to limited physical access. For these scenarios, computed tomography (CT) is often used to provide qualitative insight into surface roughness but does not directly yield roughness profile data. This research describes a hybrid approach for the non-destructive quantification of roughness profile data for lattice structures based on the mathematical reconstruction and interpretation of CT data. Formal analyses are applied to propose the theoretical minimum CT voxel size required to characterise surface roughness for a specified s ling length. The method is verified against optical data for nominally flat metallic specimens and applied to metallic and polymeric cylinders fabricated by powder bed fusion and material extrusion respectively. This research also assesses the influence of CT reconstruction thresholding as a process variable and finds that roughness profile data is only weakly influenced by thresholding settings, due to scattering effects at the surface — a novel finding that provides certainty for the industrial application of this method. The ability of the proposed method to accurately characterise the inherent surface roughness of these processes as well as the effect of specimen orientation is thus demonstrated, enabling full geometric characterisation supporting subsequent certification analysis. The method can be algorithmically implemented in combination with the generative design of complex lattice structures to support structural certification requirements.
Publisher: Springer Science and Business Media LLC
Date: 15-10-2020
Publisher: Elsevier BV
Date: 10-2004
Publisher: Elsevier BV
Date: 07-2008
Publisher: Elsevier BV
Date: 2018
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C7BM01016H
Abstract: Current understanding of the role of ordered and partially ordered surface topography in bone cell responses for bone implant design.
Publisher: Springer Science and Business Media LLC
Date: 22-09-2017
Publisher: Elsevier
Date: 2015
Publisher: Elsevier BV
Date: 11-2014
Publisher: Elsevier BV
Date: 12-2019
Publisher: Springer Science and Business Media LLC
Date: 25-09-2013
Publisher: Springer Science and Business Media LLC
Date: 21-03-2011
DOI: 10.1557/JMR.2011.13
Publisher: Trans Tech Publications, Ltd.
Date: 06-2010
DOI: 10.4028/WWW.SCIENTIFIC.NET/MSF.654-656.1339
Abstract: Turnbull’s transformation nucleus model initiated the concept of a growth barrier for a spherical-cap crystal nucleus growing on a small flat substrate. The recently developed free growth model provided a clear physical picture of the growth barrier concept with experimental and modelling support. Fletcher’s spherical substrate model enhanced the understanding of the geometrical effect of a substrate on nucleation. A recent novel analysis of Fletcher’s model furnished new insights into the similarities and differences between nucleation on spherical and flat substrates. It is necessary to distinguish between the undercooling required for nucleation and that for overcoming the growth barrier the greater one determines the early stages of grain formation.
Publisher: Springer Science and Business Media LLC
Date: 07-09-2013
Publisher: Elsevier BV
Date: 09-2021
Publisher: Elsevier BV
Date: 04-2018
Publisher: Springer Science and Business Media LLC
Date: 15-06-2010
Publisher: Springer Science and Business Media LLC
Date: 04-1996
DOI: 10.1007/BF00372201
Publisher: Elsevier BV
Date: 04-2018
Publisher: Springer Science and Business Media LLC
Date: 1999
Publisher: Elsevier BV
Date: 08-2011
Publisher: Springer Science and Business Media LLC
Date: 08-2015
Publisher: Elsevier BV
Date: 04-2016
Publisher: Research Square Platform LLC
Date: 02-2022
DOI: 10.21203/RS.3.RS-1295349/V1
Abstract: Additive Manufacturing (AM) technologies such as Laser-Based Powder Bed Fusion (LB-PBF) enables fabrication of complex lattice structures. However, LB-PBF processes inherently induce dimensional variation between idealised and as-manufactured specimens. This research proposes and implements a method to characterise the structurally relevant geometric properties of as-manufactured strut elements as demonstrated to characterise the effect of LB-PBF material (aluminium alloy and titanium) and geometric design parameters (polygon order, effective diameter and inclination angle) on the stiffness and strength of as-manufactured strut elements. Micro-computed tomography is applied to algorithmically characterise the as-manufactured variation and identify a threshold below which additional geometric resolution does not result in increased part quality. This methodology provides an algorithmic and robust Design for AM (DFAM) tool to characterise the effect of manufacturing and design parameters on the functional response of AM strut elements, as is required for certification and optimisation.
Publisher: IEEE
Date: 10-2012
Publisher: Elsevier BV
Date: 06-2006
Publisher: Elsevier BV
Date: 2021
Publisher: Elsevier BV
Date: 07-2021
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C6PY01075J
Abstract: Advances and applications of synthetic genetic polymers (xeno-nucleic acids) are reviewed in this article. The types of synthetic genetic polymers are summarized. The basic properties of them are elaborated and their technical applications are presented. Challenges and prospects of synthetic genetic polymers are discussed.
Publisher: Wiley
Date: 08-04-2016
Abstract: Enzyme mimics or artificial enzymes are a class of catalysts that have been actively pursued for decades and have heralded much interest as potentially viable alternatives to natural enzymes. Aside from having catalytic activities similar to their natural counterparts, enzyme mimics have the desired advantages of tunable structures and catalytic efficiencies, excellent tolerance to experimental conditions, lower cost, and purely synthetic routes to their preparation. Although still in the midst of development, impressive advances have already been made. Enzyme mimics have shown immense potential in the catalysis of a wide range of chemical and biological reactions, the development of chemical and biological sensing and anti-biofouling systems, and the production of pharmaceuticals and clean fuels. This Review concerns the development of various types of enzyme mimics, namely polymeric and dendrimeric, supramolecular, nanoparticulate and proteinic enzyme mimics, with an emphasis on their synthesis, catalytic properties and technical applications. It provides an introduction to enzyme mimics and a comprehensive summary of the advances and current standings of their applications, and seeks to inspire researchers to perfect the design and synthesis of enzyme mimics and to tailor their functionality for a much wider range of applications.
Publisher: Elsevier BV
Date: 05-2002
Publisher: Springer Science and Business Media LLC
Date: 30-05-2015
Publisher: Springer Science and Business Media LLC
Date: 05-2020
Publisher: Elsevier BV
Date: 02-2015
Publisher: Elsevier BV
Date: 07-2012
Publisher: Elsevier BV
Date: 03-2005
Publisher: IOP Publishing
Date: 03-2016
Publisher: Elsevier BV
Date: 11-2020
Publisher: Elsevier BV
Date: 08-2020
Publisher: Elsevier BV
Date: 11-2017
Publisher: Elsevier BV
Date: 06-2013
Publisher: Springer Science and Business Media LLC
Date: 22-06-2023
DOI: 10.1007/S40964-023-00457-0
Abstract: Additive manufacturing (AM) is a developing manufacturing technology, which provides excellent attributes compared to other manufacturing techniques. However, one of the critical challenges is the presence of defects that hinder the mechanical properties of the parts, particularly the fatigue life. Experimental understanding of fatigue is a cumbersome process. Therefore, numerical prediction based on specified conditions (such as porosity and applied load) can be an alternative to experimental analysis at the design stage of AM parts. In this study, elastic–plastic finite element analysis (FEA) is performed to obtain the stress distribution around pores, and their resultant effect on fatigue life for L-PBF (laser powder bed fusion) produced AlSi10Mg alloy s les. The stress field is calculated for both single and multiple pore models, where stress concentration is evaluated as a function of the pore’s location and its size. It is found that both pore location and size affect the stress field however, location effects dominate over pore size. For the same remote applied stress level, the stress concentration around the pore increases with an increase in pore size, and the local maximum stress occurs near the pores that are closest to the surface. The current study also evaluates the relative effect of porosity fraction, average pore size, and location. It is found that the magnitude and sensitivity of stress concentration are hierarchically controlled by porosity location, pore size, and porosity density. A multi-scale finite element (FE) model is proposed based on inherent porosity data measured using Computed Tomography (CT) to predict overall fatigue life. The fatigue cycles are calculated using the rainflow counting algorithm in FE Safe using the stress–strain data obtained from the proposed FEA model. Using the proposed model, it is possible to generate S–N curves for any loading condition for a given porosity condition (porosity density and average pore size). The S–N curve results obtained from the FE model are compared to the experimental observations. The predicted fatigue life shows approximately 5% error with experimental results at high stress loading conditions. However, the proposed model overpredicts the fatigue life at low stress loading by almost 30%.
Publisher: Elsevier BV
Date: 02-2013
Publisher: Elsevier BV
Date: 04-2011
Publisher: Elsevier BV
Date: 11-2012
Publisher: Elsevier
Date: 2015
Publisher: Elsevier BV
Date: 10-2017
Publisher: Springer Science and Business Media LLC
Date: 25-06-2020
Publisher: Elsevier BV
Date: 03-2014
Publisher: Elsevier BV
Date: 09-2023
Publisher: Trans Tech Publications, Ltd.
Date: 06-2010
DOI: 10.4028/WWW.SCIENTIFIC.NET/MSF.654-656.910
Abstract: Plate s les of Al-2Sc were processed with an electron beam (EB) gun in a vacuum of 10-3 Pa at 50kV and 30 µA. EB processing suppressed the formation of primary Al3Sc, altered the morphology of the eutectic (Al)-Al3Sc, and increased the solubility of Sc in the eutectic (Al). In addition, its cyclic heating effect induced the precipitation of Al3Sc. EB processing resulted in more profound hardening than conventional high temperature solid solution and ageing.
Publisher: Springer Science and Business Media LLC
Date: 2014
Publisher: Elsevier BV
Date: 10-2021
Publisher: Elsevier BV
Date: 07-2021
Publisher: Elsevier BV
Date: 03-2006
Publisher: AIP Publishing
Date: 05-06-2009
DOI: 10.1063/1.3146810
Abstract: Fletcher’s spherical substrate model [J. Chem. Phys. 29, 572 (1958)] is a basic model for understanding the heterogeneous nucleation phenomena in nature. However, a rigorous thermodynamic formulation of the model has been missing due to the significant complexities involved. This has not only left the classical model deficient but also likely obscured its other important features, which would otherwise have helped to better understand and control heterogeneous nucleation on spherical substrates. This work presents a rigorous thermodynamic formulation of Fletcher’s model using a novel analytical approach and discusses the new perspectives derived. In particular, it is shown that the use of an intermediate variable, a selected geometrical angle or pseudocontact angle between the embryo and spherical substrate, revealed extraordinary similarities between the first derivatives of the free energy change with respect to embryo radius for nucleation on spherical and flat substrates. Enlightened by the discovery, it was found that there exists a local maximum in the difference between the equivalent contact angles for nucleation on spherical and flat substrates due to the existence of a local maximum in the difference between the shape factors for nucleation on spherical and flat substrate surfaces. This helps to understand the complexity of the heterogeneous nucleation phenomena in a practical system. Also, it was found that the unfavorable size effect occurs primarily when R& r∗ (R: radius of substrate and r∗: critical embryo radius) and diminishes rapidly with increasing value of R/r∗ beyond R/r∗=5. This finding provides a baseline for controlling the size effects in heterogeneous nucleation.
Publisher: Elsevier BV
Date: 08-2016
Publisher: Springer Science and Business Media LLC
Date: 13-07-2018
Publisher: Springer Science and Business Media LLC
Date: 27-10-2021
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C8NH00369F
Abstract: A new in situ , simple and economical method, that combines both doping (carbon or nitrogen) and mechanical exfoliation processes to produce large quantities of doped nanosheets in one-step.
Publisher: Elsevier BV
Date: 2020
Publisher: Elsevier BV
Date: 06-2010
Publisher: Elsevier BV
Date: 05-2015
Publisher: Springer Science and Business Media LLC
Date: 10-02-2015
Publisher: Elsevier BV
Date: 04-2019
Publisher: Elsevier BV
Date: 07-2019
Publisher: Elsevier BV
Date: 10-2021
Publisher: Springer Science and Business Media LLC
Date: 02-01-2019
Publisher: Springer Science and Business Media LLC
Date: 24-03-2015
Publisher: Springer Science and Business Media LLC
Date: 18-09-2017
Publisher: Elsevier BV
Date: 11-2013
Publisher: Elsevier BV
Date: 09-2012
Publisher: Elsevier BV
Date: 2023
DOI: 10.2139/SSRN.4548909
Publisher: Springer Science and Business Media LLC
Date: 28-10-2021
Publisher: Elsevier BV
Date: 09-2012
Publisher: Informa UK Limited
Date: 02-2003
Publisher: Springer Science and Business Media LLC
Date: 31-05-2023
DOI: 10.1038/S41586-023-05952-6
Abstract: Titanium alloys are advanced lightweight materials, indispensable for many critical applications 1,2 . The mainstay of the titanium industry is the α–β titanium alloys, which are formulated through alloying additions that stabilize the α and β phases 3–5 . Our work focuses on harnessing two of the most powerful stabilizing elements and strengtheners for α–β titanium alloys, oxygen and iron 1–5 , which are readily abundant. However, the embrittling effect of oxygen 6,7 , described colloquially as ‘the kryptonite to titanium’ 8 , and the microsegregation of iron 9 have hindered their combination for the development of strong and ductile α–β titanium–oxygen–iron alloys. Here we integrate alloy design with additive manufacturing (AM) process design to demonstrate a series of titanium–oxygen–iron compositions that exhibit outstanding tensile properties. We explain the atomic-scale origins of these properties using various characterization techniques. The abundance of oxygen and iron and the process simplicity for net-shape or near-net-shape manufacturing by AM make these α–β titanium–oxygen–iron alloys attractive for a erse range of applications. Furthermore, they offer promise for industrial-scale use of off-grade sponge titanium or sponge titanium–oxygen–iron 10,11 , an industrial waste product at present. The economic and environmental potential to reduce the carbon footprint of the energy-intensive sponge titanium production 12 is substantial.
Publisher: Elsevier BV
Date: 04-2021
Publisher: Elsevier
Date: 2019
Publisher: Elsevier BV
Date: 06-2023
Publisher: Ivyspring International Publisher
Date: 2016
DOI: 10.7150/THNO.15850
Publisher: Springer Science and Business Media LLC
Date: 1999
Publisher: Elsevier BV
Date: 11-2012
Publisher: Informa UK Limited
Date: 09-1990
Publisher: Elsevier BV
Date: 07-2010
Publisher: Elsevier
Date: 2015
Publisher: Springer Science and Business Media LLC
Date: 2001
Publisher: Springer Science and Business Media LLC
Date: 04-03-2022
DOI: 10.1007/S11837-021-05144-5
Abstract: Additively manufactured (AM) lattice structures are applied in high-value applications such as lightweight aerospace design and biomedical implants. However, uncertainties of the geometry of as-manufactured AM lattice structures results in uncertainties in the associated mechanical response. This research proposes a non-destructive digital-twin certification methodology that quantifies the functional response of in idual strut elements (and associated statistical distributions) from x-ray micro-computed tomography (µCT) data for as-manufactured AM lattice structures. This methodology may be algorithmically applied, as is required for the cost-effective certification of high-value lattice structures. The proposed methodology is demonstrated for a digital twin of over 2000 strut elements within a Ti-6AI-4V lattice fabricated with laser-based powder bed fusion. This digital twin allows various geometric or functional analyses to be performed, and in this case is demonstrated by acquiring statistical distributions of the predicted critical buckling load as a function of the strut element build orientation.
Publisher: Springer Science and Business Media LLC
Date: 30-06-2021
Publisher: Elsevier BV
Date: 12-1994
Publisher: Springer Science and Business Media LLC
Date: 07-2005
Publisher: Elsevier BV
Date: 04-2019
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C4RA15622F
Abstract: The creation of nanoporous Cu 3 Sn–Cu–Cu 6 Sn 5 composite structures in the form of self-supporting foils through the concurrence of de-alloying and re-alloying.
Publisher: Elsevier BV
Date: 05-2010
Publisher: Elsevier BV
Date: 10-2014
Publisher: Elsevier
Date: 2015
Publisher: Wiley
Date: 02-2014
Publisher: Elsevier BV
Date: 03-2020
Publisher: Elsevier BV
Date: 03-2022
Publisher: Elsevier BV
Date: 2020
Publisher: Elsevier BV
Date: 02-2017
Publisher: Wiley
Date: 09-2007
Publisher: Elsevier BV
Date: 09-1970
Publisher: Elsevier BV
Date: 12-2012
Publisher: Elsevier BV
Date: 10-2018
Publisher: Elsevier BV
Date: 12-2013
Publisher: Informa UK Limited
Date: 20-10-2021
Publisher: Wiley
Date: 18-03-2019
Publisher: Elsevier BV
Date: 05-2020
Publisher: Elsevier BV
Date: 12-2020
Publisher: Elsevier BV
Date: 04-2022
Publisher: Springer Science and Business Media LLC
Date: 06-01-2020
Publisher: Elsevier BV
Date: 2024
Publisher: Elsevier BV
Date: 04-1996
Publisher: Elsevier BV
Date: 07-2023
Publisher: Springer Science and Business Media LLC
Date: 29-03-2011
Publisher: Elsevier BV
Date: 07-2013
Publisher: Springer Science and Business Media LLC
Date: 09-04-2020
Publisher: Informa UK Limited
Date: 04-2002
Publisher: Springer Science and Business Media LLC
Date: 08-2012
Publisher: Elsevier
Date: 2018
Publisher: Elsevier BV
Date: 2019
Publisher: Springer Science and Business Media LLC
Date: 29-01-2015
Publisher: Elsevier BV
Date: 06-2017
Publisher: Elsevier BV
Date: 12-2020
Publisher: SAE International
Date: 03-03-2003
DOI: 10.4271/2003-01-1365
Publisher: Elsevier BV
Date: 06-2006
Publisher: Elsevier BV
Date: 12-1994
Publisher: Elsevier BV
Date: 07-2004
Publisher: Mary Ann Liebert Inc
Date: 02-2021
Publisher: Springer Science and Business Media LLC
Date: 03-04-2023
DOI: 10.1007/S00170-023-11251-1
Abstract: Additive manufacturing (AM) technologies such as laser-based powder bed fusion (LB-PBF) facilitate the fabrication of complex lattice structures. However, these structures consistently display dimensional variation between the idealised and as-manufactured specimens. This research proposes a method to characterise the impact of common LB-PBF powders (aluminium and titanium alloys) and geometric design parameters (polygon order, effective diameter, and inclination angle) on section properties relevant to stiffness and strength of as-manufactured strut elements. Micro-computed tomography (µCT) has been applied to algorithmically characterise the as-manufactured variation and identify a scale threshold below which additional geometric resolution does not influence the section properties of as-manufactured parts. This methodology provides a robust and algorithmic design for additive manufacturing (DFAM) tool to characterise the effects of manufacturing and design parameters on the functional response of AM strut elements, as is required for certification and optimisation.
Publisher: Elsevier
Date: 2010
Publisher: Elsevier BV
Date: 12-2014
Publisher: Elsevier BV
Date: 09-2011
Publisher: Elsevier BV
Date: 07-2013
Publisher: Hindawi Limited
Date: 2013
DOI: 10.1155/2013/101508
Abstract: Metallic glass powder of the composition Al 86 Ni 6 Y 4.5 Co 2 La 1.5 was consolidated into 10 mm diameter s les by spark plasma sintering (SPS) at different temperatures under an applied pressure of 200 MPa or 600 MPa. The heating rate and isothermal holding time were fixed at 40°C/min and 2 min, respectively. Fully dense bulk metallic glasses (BMGs) free of particle-particle interface oxides and nano-crystallization were fabricated under 600 MPa. In contrast, residual oxides were detected at particle-particle interfaces (enriched in both Al and O) when fabricated under a pressure of 200 MPa, indicating the incomplete removal of the oxide surface layers during SPS at a low pressure. Transmission electron microscopy (TEM) revealed noticeable nano-crystallization of face-centered cubic (fcc) Al close to such interfaces. Applying a high pressure played a key role in facilitating the removal of the oxide surface layers and therefore full densification of the Al 86 Ni 6 Y 4.5 Co 2 La 1.5 metallic glass powder without nano-crystallization. It is proposed that applied high pressure, as an external force, assisted in the breakdown of surface oxide layers that enveloped the powder particles in the early stage of sintering. This, together with the electrical discharge during SPS, may have benefitted the viscous flow of metallic glasses during sintering.
Publisher: AIP Publishing
Date: 07-03-2018
DOI: 10.1063/1.5020517
Abstract: Surface wettability plays a critical role in a variety of key areas including orthopaedic implants and chemical engineering. Anisotropy in wettability can arise from surface grooves, which are of particular relevance to orthopaedic implants because they can mimic collagen fibrils that are the basic components of the extracellular matrix. Titanium (Ti) and its alloys have been widely used for orthopaedic and dental implant applications. This study is concerned with the fabrication of Ti-coated microgrooves with different groove widths and the characterisation of the anisotropy in wettability through measuring water contact angles, compared with both the Wenzel and Cassie models. Experimental results revealed that there existed significant anisotropy in the wettability of Ti-coated microgrooves, and the degree of anisotropy (Δθ) increased with an increasing groove width from 5 μm to 20 μm. On average, the contact angle measured parallel to the groove direction (θ//) was about 50°–60° smaller than that measured perpendicular to the groove direction (θ⊥). In general, the Wenzel model predicted the contact angles along the surface groove direction reasonably, and so did the Cassie model for the contact angles perpendicular to the groove direction. Osteoblast spreading was affected by the anisotropy in wettability, which occurred preferably along, rather than perpendicular to, the groove direction. These findings are informative for the design of Ti implant surfaces when anisotropy in wettability matters.
Publisher: Japan Society of Mechanical Engineers
Date: 1999
Publisher: Elsevier BV
Date: 06-2018
Publisher: Elsevier BV
Date: 04-2013
Publisher: Informa UK Limited
Date: 02-2014
Publisher: Springer Science and Business Media LLC
Date: 29-08-2017
DOI: 10.1557/JMR.2017.345
Publisher: Elsevier BV
Date: 2006
Publisher: Elsevier BV
Date: 04-2023
Publisher: Elsevier BV
Date: 12-2017
Publisher: Springer Science and Business Media LLC
Date: 17-07-2017
Publisher: Elsevier BV
Date: 04-2012
Publisher: Elsevier
Date: 2019
Publisher: Springer Science and Business Media LLC
Date: 24-01-2020
Publisher: Elsevier BV
Date: 03-2020
Publisher: Springer Science and Business Media LLC
Date: 22-01-2016
Publisher: Trans Tech Publications Ltd.
Date: 15-03-2006
Publisher: Springer Science and Business Media LLC
Date: 13-08-2009
Publisher: Wiley
Date: 02-2014
Publisher: Elsevier BV
Date: 12-2019
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Start Date: 2022
End Date: 2025
Funder: Marsden Fund
View Funded ActivityStart Date: 2020
End Date: 12-2024
Amount: $456,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2015
End Date: 12-2019
Amount: $310,700.00
Funder: Australian Research Council
View Funded ActivityStart Date: 03-2022
End Date: 03-2025
Amount: $450,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2014
End Date: 05-2017
Amount: $475,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2009
End Date: 08-2012
Amount: $750,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 10-2014
End Date: 06-2020
Amount: $5,000,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2014
End Date: 04-2015
Amount: $890,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 06-2015
End Date: 12-2020
Amount: $420,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2018
End Date: 05-2021
Amount: $367,734.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2003
End Date: 07-2006
Amount: $84,099.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2023
End Date: 12-2023
Amount: $450,294.00
Funder: Australian Research Council
View Funded ActivityStart Date: 06-2015
End Date: 06-2018
Amount: $360,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2017
End Date: 06-2018
Amount: $1,100,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 07-2014
End Date: 06-2016
Amount: $250,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 07-2014
End Date: 03-2018
Amount: $295,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 07-2005
End Date: 12-2014
Amount: $22,550,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2011
End Date: 12-2012
Amount: $430,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2013
End Date: 12-2015
Amount: $390,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 01-2012
End Date: 12-2015
Amount: $350,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 03-2019
End Date: 03-2025
Amount: $4,889,410.00
Funder: Australian Research Council
View Funded Activity