ORCID Profile
0000-0003-2684-1994
Current Organisations
Monash University
,
Indian Institute of Technology Kanpur
,
North Carolina State University
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Publisher: Springer Science and Business Media LLC
Date: 09-06-2010
Publisher: Springer Science and Business Media LLC
Date: 27-03-2012
Publisher: InTech
Date: 30-03-2012
DOI: 10.5772/34928
Publisher: Pleiades Publishing Ltd
Date: 05-2020
Publisher: Elsevier BV
Date: 11-2020
Publisher: Association for Materials Protection and Performance (AMPP)
Date: 17-11-2020
DOI: 10.5006/3633
Abstract: In this work, nine nanocrystalline binary Mg alloys were synthesized by high-energy ball milling. The compositions, Mg-5 wt% M (M-Cr, Ge, Mn, Mo, Ta, Ti, V, Y, and Zn), were milled with the objective of achieving non-equilibrium alloying. The milled alloys were consolidated via cold compaction (CC) at 25°C and spark plasma sintering (SPS) at 300°C. X-ray diffraction (XRD) analysis indicated grain refinement below 100 nm, and the scanning electron microscopy revealed homogeneous microstructures for all compositions. XRD analysis revealed that most of the alloys showed a change in the lattice parameter, which indicates the formation of a solid solution. A significant increase in the hardness compared to unmilled Mg was observed for all of the alloys. The corrosion behavior was improved in all of the binary alloys compared to milled Mg. A significant decrease in the cathodic kinetics was evident due to Ge and Zn additions. The influence of the alloying elements on corrosion behavior has been categorized and discussed based on the electrochemical response of their respective binary Mg alloys.
Publisher: Elsevier BV
Date: 04-2012
Publisher: Elsevier BV
Date: 12-2019
Publisher: Association for Materials Protection and Performance (AMPP)
Date: 17-10-2013
DOI: 10.5006/0804
Abstract: Sensitization of 5xxx series Al alloys involving precipitation of β phase (Mg2Al3) at grain boundaries was studied for different exposure times at 100°C upon AA5083-H131 (UNS A95083). In this work, we reveal that fracture surfaces prepared by liquid gallium embrittlement can yield a quantification of grain boundary β phase with significant statistics on β phase size and spacing. This information is a necessary first step toward development of quantitative damage models to describe inter-granular corrosion (IGC) and stress corrosion (IGSCC).
Publisher: Elsevier BV
Date: 06-2020
Publisher: Elsevier BV
Date: 05-2023
Publisher: Springer Science and Business Media LLC
Date: 10-10-2022
Publisher: Elsevier BV
Date: 08-2022
Publisher: Elsevier BV
Date: 10-2023
Publisher: Springer Science and Business Media LLC
Date: 08-09-2022
Publisher: Elsevier BV
Date: 05-2013
Publisher: Springer Science and Business Media LLC
Date: 10-08-2022
Publisher: Association for Materials Protection and Performance (AMPP)
Date: 22-02-2013
DOI: 10.5006/0870
Abstract: The effect of varying the percent crystallinity on the electrochemical behavior of Mg65Cu25Y10 and Mg70Zn25Ca5 bulk metallic glasses was studied. The alloys were heat-treated to achieve desired microstructures ranging from fully amorphous to fully crystalline, providing a systematic basis for subsequent testing. Potentiodynamic experiments in 0.01 M sodium chloride (NaCl) were used, whereby both the amorphous and partially crystallized s les were observed to have more noble corrosion potentials and lower anodic kinetics. However, this was accompanied by more rapid cathodic kinetics relative to their fully crystalline counterparts, meaning that corrosion rates were not significantly lower in the amorphous state. To describe the electrochemical response as a function of the degree of crystallinity, differential scanning calorimetry (DSC), scanning electron microscopy, x-ray diffraction (XRD), and electrical conductivity measurements were undertaken, where it was found that crystallinity alone is not necessarily the controlling factor and microchemistry that evolves upon devitrification, plays a key role in the electrochemical response of these materials.
Publisher: Elsevier BV
Date: 09-2022
Publisher: The Electrochemical Society
Date: 03-2023
Abstract: Nanocrystalline supersaturated Al-V alloys produced by high-energy ball milling have been reported to exhibit enhanced corrosion resistance and mechanical properties compared to commercial Al alloys. Corrosion of passive alloys such as Al-V alloy relies on the characteristics of the surface film, which is studied using scanning/transmission electron microscopy and time-of-flight secondary ion mass spectrometry. The effect of microstructure and composition on the surface film has been investigated after different immersion periods (30 min, 2 h, and 1 day) in 0.1 M NaCl. The surface film was complex and composed of oxidized Al and V. The heterogeneous surface film was observed due to the presence of secondary phases and initiation of localized corrosion. The void formation was observed beneath the surface film that would potentially cause pitting corrosion. The generation of nano-sized voids was dependent on grain orientation. Compared to pure Al, the chloride penetration is suppressed in Al-V alloys. The effect of composition and microstructure on surface film formation and attendant corrosion behavior is discussed herein.
Publisher: Trans Tech Publications, Ltd.
Date: 06-2010
DOI: 10.4028/WWW.SCIENTIFIC.NET/MSF.654-656.1122
Abstract: Nanocrystalline and microcrystalline Fe-10Cr alloys were prepared by high energy ball milling followed by compaction and sintering, and then oxidized in air for 52 hours at 400°C. The oxidation resistance of nanocrystalline Fe-10Cr alloy as determined by measuring the weight gain after regular time intervals was compared with that of the microcrystalline alloy of same chemical composition (also prepared by the same processing route and oxidized under identical conditions). Oxidation resistance of nanocrystalline Fe10Cr alloy was found to be in excess of an order of magnitude superior than that of microcrystalline Fe10Cr alloy. The paper also presents results of secondary ion mass spectrometry of oxidized s les of nanocrystalline and microcrystalline Fe-Cr alloys, evidencing the formation of a more protective oxide scale in the nanocrystalline alloy.
Publisher: Springer Science and Business Media LLC
Date: 05-10-2011
Publisher: Elsevier BV
Date: 08-2013
Publisher: Elsevier BV
Date: 09-2023
Publisher: Elsevier BV
Date: 04-2022
Publisher: Informa UK Limited
Date: 14-10-2020
Publisher: Springer Science and Business Media LLC
Date: 10-2018
Publisher: Elsevier BV
Date: 08-2018
Publisher: Springer Science and Business Media LLC
Date: 19-03-2021
DOI: 10.1038/S41529-021-00158-5
Abstract: A compositionally complex alloy was designed, consisting of equiatomic concentrations of four low-cost commodity elements (Al, Fe, Mn, and Si). The alloy was characterized using scanning electron microscopy and energy-dispersive X-ray spectroscopy. The corrosion of the AlFeMnSi alloy, as evaluated using potentiodynamic polarization tests and electrochemical impedance spectroscopy in 0.6 M NaCl solution, was comparable with that of stainless steel (SS) 304L. Detailed X-ray photoelectron spectroscopy analysis was carried out, including the determination of high-resolution spectra and surface sputtering. In addition, scanning transmission electron microscopy was also used to study the surface film(s) developed after constant immersion. The AlFeMnSi alloy exhibited a unique form of ‘passivity’ that arises from the development of a silicon-rich surface film from dynamic incongruent dissolution.
Publisher: The Electrochemical Society
Date: 2013
DOI: 10.1149/2.001308JES
Publisher: Springer Science and Business Media LLC
Date: 20-01-2022
DOI: 10.1038/S41529-021-00215-Z
Abstract: Additive manufacturing (AM) is an emerging technology to produce engineering components. However, the major challenge in the practical application of AM is the inconsistent properties of additively manufactured components. This research presents a strategy of feedstock modification to improve the corrosion performance of selective laser melted (SLM) 316L stainless steel (SS). Modified feedstock powders were produced by ball-milling of commercial-316LSS powder with 1wt.% chromium nitride (CrN). The SLM coupons produced from modified feedstock powders (SLM-316L/CrN) exhibited significantly improved corrosion performance, as evident from the high pitting and repassivation potentials and absence of metastable pitting. The microstructural characterization revealed fine oxide-inclusions comprising Si, Mn, and S in SLM-316L and only Si and Mn in SLM-316L/CrN. The absence of sulfur-containing oxide-inclusions in SLM-316L/CrN and refined cellular structure, and the change in chemical composition were attributed to corrosion resistance enhancement due to the CrN addition.
Publisher: Elsevier BV
Date: 09-2015
Publisher: Elsevier BV
Date: 09-2023
Publisher: MDPI AG
Date: 11-08-2020
DOI: 10.3390/MET10081082
Abstract: Intergranular corrosion (IGC) and pitting transition caused by grain boundary β-phase saturation of aluminum alloy AA5083 sensitized at 150 °C was investigated in 3.5 wt% NaCl solution. The change in the localized corrosion mechanism from IGC to pitting was studied by microstructural and electrochemical analysis, where IGC was found to be the primary mechanism at low degrees of sensitization (DoS) and pitting corrosion was observed to develop after grain boundary β-phase saturation. Evaluation of the double layer capacitance by electrochemical impedance spectroscopy (EIS) and charge passed through the specimens by potentiostatic current monitoring demonstrated a well differentiated three-stage dissolution mechanism.
Publisher: Elsevier BV
Date: 02-2009
Publisher: Elsevier BV
Date: 09-2022
DOI: 10.1016/J.GIM.2022.05.014
Abstract: Single-nucleotide variations (SNVs) (formerly single-nucleotide polymorphism [SNV]) influence genetic predisposition to endometrial cancer. We hypothesized that a polygenic risk score (PRS) comprising multiple SNVs may improve endometrial cancer risk prediction for targeted screening and prevention. We developed PRSs from SNVs identified from a systematic review of published studies and suggestive SNVs from the Endometrial Cancer Association Consortium. These were tested in an independent study of 555 surgically-confirmed endometrial cancer cases and 1202 geographically-matched controls from Manchester, United Kingdom and validated in 1676 cases and 116,960 controls from the UK Biobank (UKBB). Age and body mass index predicted endometrial cancer in both data sets (Manchester: area under the receiver operator curve [AUC] = 0.77, 95% CI = 0.74-0.80 UKBB: AUC = 0.74, 95% CI = 0.73-0.75). The AUC for PRS19, PRS24, and PRS72 were 0.58, 0.55, and 0.57 in the Manchester study and 0.56, 0.54, and 0.54 in UKBB, respectively. For PRS19, women in the third tertile had a 2.1-fold increased risk of endometrial cancer compared with those in the first tertile of the Manchester study (odds ratio = 2.08, 95% CI = 1.61-2.68, P An endometrial cancer risk prediction model incorporating a PRS derived from multiple SNVs may help stratify women for screening and prevention strategies.
Publisher: Elsevier BV
Date: 12-2018
Publisher: Springer Science and Business Media LLC
Date: 08-05-2012
Publisher: Elsevier BV
Date: 12-2018
Publisher: The Electrochemical Society
Date: 07-07-2022
DOI: 10.1149/MA2022-01161013MTGABS
Abstract: Additive manufacturing (AM) is an emerging technology that can build 3d-component in a single step via the layer-by-layer process. Selective laser melting (SLM) is a popular powder bed fusion (PBF) – AM technique that involves rapid heating and cooling cycles with broad temperature gradients and complex thermal history. Moreover, the SLM components are often reported to have lower build densification due to stochastic porosity. The complex thermal cycles and stochastic porosity can negatively influence the corrosion performance of SLM printed 316L Stainless steel (SLM-316L) alloys. The corrosion performance of SLM-316L can be improved by optimizing the SLM processing parameters to improve the density and/or performing post-processing. However, post-processing increases the cost and time to deliver the components and is desired to avoid. Therefore, modifying the feedstock to increase corrosion resistance and therefore tolerance of the pores would help streamline the workflow and eliminate expensive post-manufacturing steps. In this research, the feedstock modification was conducted using ball milling of various additives and 316L powder. Corrosion performance of the SLM specimen was dependent on the additive used to modify the feedstock. Some of the additives imparted significantly improved corrosion performance, as evident from the high pitting and repassivation potentials and absence of metastable pitting. Observed corrosion performance was correlated with the microstructure which was studied using scanning and transmission electron microscopes. X-ray photoelectron spectroscopy and time of flight secondary ion mass spectrometry was used to study the surface film. Role of additives on microstructure and corrosion performance will be discussed.
Publisher: Informa UK Limited
Date: 05-12-2014
Publisher: Informa UK Limited
Date: 10-04-2014
Publisher: Elsevier BV
Date: 10-2017
Publisher: Elsevier BV
Date: 05-2018
Publisher: Association for Materials Protection and Performance (AMPP)
Date: 07-07-2016
DOI: 10.5006/1703
Publisher: Elsevier BV
Date: 03-2015
Publisher: Elsevier BV
Date: 03-2021
Publisher: Elsevier BV
Date: 11-2015
Publisher: The Electrochemical Society
Date: 2014
DOI: 10.1149/2.056404JES
Publisher: The Electrochemical Society
Date: 09-10-2022
DOI: 10.1149/MA2022-0211724MTGABS
Abstract: Al alloys with far-from-equilibrium compositions and microstructures are reported to possess high corrosion resistance and strength. These alloys produced are by non-equilibrium processing techniques such as high-energy ball milling, sputtering, and ion implantation. Depending on the processing techniques and conditions, the microstructure of the alloys could be heterogeneous. For ex le, alloys produced by high-energy ball milling and subsequent consolidation comprise a matrix with high solid solubility of the solute and uniformly distributed secondary phases. Such a heterogeneous microstructure is expected to influence the passive film composition and localized corrosion mechanisms. In the present study, passive film composition on the ball-milled alloys was studied using a combination of scanning transmission electron microscope, X-ray photoelectron spectroscopy, and secondary ion mass spectrometry (SIMS). Additionally, pits and regions near pits were investigated which helped in understanding factors causing pit initiation and repassivation.
Publisher: MDPI AG
Date: 03-08-2023
DOI: 10.20944/PREPRINTS202308.0307.V1
Abstract: The objective of this study is to examine a nonparametric estimate , using the kernel approach, of the conditional distribution function of a scalar response variable that is given a random variable whose values take place in a separable real Hilbert space. The observations will be dependent on one another in a quasi-associated fashion. The pointwise practically perfect consistencies with rates of this estimator are established by us under some broad conditions. The study’s major objective is to investigate the convergence rate of the proposed estimator and its application in the convergence rate and asymptotic normality of the hazard function. The asymptotic normality of the developed estimator is established precisely. Simulation studies were conducted to investigate the behavior of the asymptotic property in the context of finite s le data.
Publisher: Elsevier BV
Date: 07-2021
Publisher: Springer International Publishing
Date: 2017
Publisher: MDPI AG
Date: 23-11-2020
DOI: 10.3390/MA13225306
Abstract: Titanium carbide (TiC) reinforced nickel (Ni) matrix composites were processed via mechanical alloying (MA) followed by spark plasma sintering (SPS) process. Mechanical alloying has gained special attention as a powerful non-equilibrium process for fabricating amorphous and nanocrystalline materials, whereas spark plasma sintering (SPS) is a unique technique for processing dense and near net shape bulk alloys with homogenous microstructure. TiC reinforcement varied from 5 to 50 wt.% into nickel matrix to investigate its effect on the microstructure and mechanical behavior of Ni-TiC composites. All Ni-TiC composites powder was mechanically alloyed using planetary high energy ball mill with 400 rpm and ball to powder ratio (BPR) 15:1 for 24 h. Bulk Ni-TiC composites were then sintered via SPS process at 50 MPa pressure and 900–1200 °C temperature. All Ni-TiC composites exhibited higher microhardness and compressive strength than pure nickel due to the presence of homogeneously distributed TiC particles within the nickel matrix, matrix grain refinement, and excellent interfacial bonding between nickel and TiC reinforcement. There is an increase in Ni-TiC composites microhardness with an increase in TiC reinforcement from 5 to 50 wt.%, and it reaches the maximum value of 900 HV for Ni-50TiC composites.
Publisher: Springer Science and Business Media LLC
Date: 23-09-2020
DOI: 10.1007/S12529-020-09932-2
Abstract: Few in iduals with metastatic prostate cancer have access to prostate cancer-specific exercise support, despite demonstrated benefits. eHealth tools, such as websites, may be viable options for increasing access. To be effective and acceptable, future eHealth websites need to consider end-users' perspectives, capacity and needs. We aim to provide insight into these factors by exploring daily priorities, activities and health literacy of in iduals with metastatic prostate cancer and their perspectives towards exercise and exercise-based web-based eHealth interventions. Semi-structured interviews explored participant's experiences and understanding of their disease, exercise levels, advice received from health care providers, as well as acceptability of and suggested content for an eHealth tool. A thematic analysis was undertaken. Interviews were conducted with eighteen Australians (55-83 years M = 71.5, SD = 8.9) living with metastatic prostate cancer. Needing to perform daily responsibilities was a key priority. Participants had limited understanding of the benefits of prostate cancer-specific exercise, and less than half discussed exercise with their health team. Fourteen men felt they could report metastases location, but only four could provide detailed information, which has clinical implications for exercise prescription. A potential web-based intervention was considered acceptable by seventeen men for reasons such as affordability, accessibility and convenience. User-friendly design and practitioner support were important. Results identified key aspects useful for person-centred design of exercise programs. Participants were positive towards the proposed web-based tool and expressed the need for in idualised, user-friendly and reliable information with support from a professional embedded. Lastly, not all participants could accurately report metastasis locations.
Publisher: The Electrochemical Society
Date: 05-01-2020
Abstract: Commercial aluminum alloys exhibit localized corrosion when exposed to environments containing aggressive anions. Alloying of Al with specific elements (M: Cr, Mo, V, Nb, etc) using non-equilibrium processing techniques has been reported to result in significantly improved corrosion resistance due to the formation of a supersaturated solid solution and uniform distribution of M in the matrix. Several theories describing the corrosion behavior of Al–M alloys have been postulated. This paper presents an overview of the most common non-equilibrium alloying techniques implemented for the production of the metastable Al–M alloys and posited corrosion mechanisms for the improved corrosion resistance.
Publisher: Elsevier BV
Date: 02-2023
Publisher: Elsevier BV
Date: 12-2022
Publisher: Elsevier BV
Date: 02-2021
Publisher: MDPI AG
Date: 24-06-2021
DOI: 10.3390/MA14133536
Abstract: Carbon nanotubes (CNTs) and graphene nanoplatelets (GNPs) with exceptional mechanical, thermal, chemical, and electrical properties are enticing reinforcements for fabricating lightweight, high-strength, and wear-resistant metal matrix composites with superior mechanical and tribological performance. Nickel–carbon nanotube composite (Ni-CNT) and nickel–graphene nanoplatelet composite (Ni-GNP) were fabricated via mechanical milling followed by the spark plasma sintering (SPS) technique. The Ni-CNT/GNP composites with varying reinforcement concentrations (0.5, 2, and 5 wt%) were ball milled for twelve hours to explore the effect of reinforcement concentration and its dispersion in the nickel microstructure. The effect of varying CNT/GNP concentration on the microhardness and the tribological behavior was investigated and compared with SPS processed monolithic nickel. Ball-on-disc tribological tests were performed to determine the effect of different structural morphologies of CNTs and GNPs on the wear performance and coefficient of friction of these composites. Experimental results indicate considerable grain refinement and improvement in the microhardness of these composites after the addition of CNTs/GNPs in the nickel matrix. In addition, the CNTs and GNPs were effective in forming a lubricant layer, enhancing the wear resistance and lowering the coefficient of friction during the sliding wear test, in contrast to the pure nickel counterpart. Pure nickel demonstrated the highest CoF of ~0.9, Ni-0.5CNT and Ni-0.5GNP exhibited a CoF of ~0.8, whereas the lowest CoF of ~0.2 was observed for Ni-2CNT and Ni-5GNP composites. It was also observed that the uncertainty of wear resistance and CoF in both the CNT/GNP-reinforced composites increased when loaded with higher reinforcement concentrations. The wear surface was analyzed using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) analysis to elucidate the wear mechanism in these composites.
Publisher: The Electrochemical Society
Date: 2012
DOI: 10.1149/2.062211JES
Publisher: Elsevier BV
Date: 06-2021
Publisher: The Electrochemical Society
Date: 07-07-2022
DOI: 10.1149/MA2022-01161017MTGABS
Abstract: Corrosion is a massive disaster in many sectors that caused the loss of billions of dollars. For ex le, it was reported that the total direct estimated cost of corrosion was about $ 276 billion in 1998 in the US, which is 3.1% of the nation’s GDP. Therefore, a necessity to develop methods to overcome this challenge arose in the last few decades. Thus, the development of corrosion resistive coatings is significantly attracted researchers' attention. In combination with the corrosion inhibitors, organic and conversion coatings are used to improve the corrosion resistance of high-strength Al alloys. However, many corrosion inhibitors are carcinogenic: Chromate conversion coating performed very well, but alternative options need to be explored due to restrictions on its applications due to the health and environmental regulations. Moreover, organic coatings provide good corrosion resistance, but poor wear resistance and mechanical damage lead to corrosion issues. Metallic coatings are an alternative, and galvanized steel is one of the prominent ex les. However, metallic coatings produced by elements such as Cr, Ni, Ti, or Ta are noble for Al or Mg-based alloys. Therefore, in any event of coating breakdown, the substrate would be more active and act as an anode and, corrode rapidly by galvanic interaction. Thus, such metallic coatings produced by the above-mentioned corrosion resistance elements are not very attractive for Al alloys. We present a sacrificial metallic coating with outstanding corrosion resistance. Al was alloyed with V using high-energy ball milling (HEBM) which enabled the formation of a superstrated solid solution of V in Al. Al-V alloy powder produced by HEBM was used for coating the high-strength substrate using cold spray. The corrosion behavior and corrosion mechanisms of cold sprayed specimens were investigated using advanced electrochemical and analytical techniques. The cold sprayed specimens exhibit high pitting potential, low corrosion current density, and a less noble corrosion potential than the substrate. This indicates that in any event of coating breakdown, the coating would corrode (i.e., act as a sacrificial anode) and prevent the substrate from corrosion. Alloy composition is chosen such that corrosion of coating releases chemical species that could inhibit corrosion by decreasing the cathodic efficiency of the substrate.
Publisher: Elsevier BV
Date: 11-2015
Publisher: Springer International Publishing
Date: 2021
Publisher: Elsevier BV
Date: 10-2022
Publisher: Elsevier BV
Date: 09-2022
Publisher: Elsevier BV
Date: 09-2020
Publisher: Springer Science and Business Media LLC
Date: 17-02-2022
DOI: 10.1038/S41529-022-00225-5
Abstract: Supersaturated solid solutions of Al and corrosion-resistant alloying elements (M: V, Mo, Cr, Ti, Nb), produced by non-equilibrium processing techniques, have been reported to exhibit high corrosion resistance and strength. The corrosion mechanism for such improved corrosion performance has not been well understood. We present a fundamental understanding of the role of V in corrosion of an Al-V alloy, which will provide a theoretical background for developing corrosion-resistant Al alloys. High-energy ball milling of the elemental powder of Al and V produced an in situ consolidated Al-V alloy, which exhibited high solid solubility of V. The corrosion resistance of Al-V alloy was significantly higher than that of pure Al, which was attributed to the (1) enrichment of V at the passive film/substrate interface, (2) incorporation of V into the passive film, and (3) deposition of V on the iron-containing cathodic particles and therefore, retardation of cathodic reaction.
Publisher: Association for Materials Protection and Performance (AMPP)
Date: 09-04-2023
DOI: 10.5006/4245
Abstract: Laser powder bed fusion (LPBF), a metal additive manufacturing technique, was conducted on feedstock-modified 316L stainless steel (316L) powder produced by ball-milling of commercial 316L and 1 wt% additive (cerium oxide—CeO2, lanthanum (III) nitrate hexahydrate—La(NO3)3·6H2O, and chromium nitride—CrN). The feedstock-modified LPBF-316L specimens were sensitized at 675°C for 24 h, and the influence of additives on intergranular corrosion (IGC) was investigated following ASTM G108-94 and A262-14 standards. The LPBF-316L with La(NO3)3·6H2O showed higher IGC resistance. The microstructure of the LPBF specimen was investigated and correlated to understand the improved IGC resistance of LPBF-316L with La(NO3)3·6H2O additive.
Publisher: Pleiades Publishing Ltd
Date: 05-2018
Publisher: Informa UK Limited
Date: 08-2010
Publisher: Elsevier BV
Date: 05-2014
Publisher: Association for Materials Protection and Performance (AMPP)
Date: 2013
DOI: 10.5006/0833
Publisher: Elsevier BV
Date: 10-2008
Publisher: The Electrochemical Society
Date: 2012
DOI: 10.1149/2.002201EEL
Publisher: The Electrochemical Society
Date: 09-0007
Publisher: Springer Science and Business Media LLC
Date: 24-03-2021
Publisher: Springer Science and Business Media LLC
Date: 17-02-2017
Publisher: Wiley
Date: 08-06-2015
Publisher: Springer Science and Business Media LLC
Date: 24-04-2018
Publisher: The Electrochemical Society
Date: 08-01-2020
DOI: 10.1149/OSF.IO/EW86M
Abstract: A new class of compositionally complex alloy, consisting of equiatomic concentrations of Al, Fe, Mn and Si is reported. The alloy was characterized using scanning electron microscopy and energy-dispersive X-ray spectroscopy. Corrosion behavior of the AlFeMnSi alloy, as evaluated using potentiodynamic polarization tests and electrochemical impedance spectroscopy in 0.6 M NaCl solution, was comparable with that of stainless steel (SS) 304L. X-ray photoelectron spectroscopy was used to study the AlFeMnSi surface film. The AlFeMnSi alloy also exhibited a lower cost, lower density, and a higher hardness as compared with SS 304L, rendering it a promising alloy for bespoke applications.
Publisher: CRC Press
Date: 06-04-2023
Publisher: Elsevier BV
Date: 11-2018
Publisher: Association for Materials Protection and Performance (AMPP)
Date: 02-10-2018
DOI: 10.5006/2967
Publisher: Association for Materials Protection and Performance (AMPP)
Date: 04-2014
DOI: 10.5006/1117
Publisher: Elsevier BV
Date: 03-2021
Publisher: Elsevier BV
Date: 09-2021
Publisher: Association for Materials Protection and Performance (AMPP)
Date: 31-05-2013
DOI: 10.5006/0948
Abstract: The influence of Mg content on the degree of sensitization (DoS) of Al-xMg-0.5Mn (wt%) alloys (where x varies from 3.36 wt% to 8.85 wt%) was investigated via the nitric acid mass loss test (NAMLT). NAMLT upon sensitized specimens revealed that mass loss was negligible below ~4.01 wt% Mg, while for Mg content ≥4.01 wt%, mass loss increased monotonically. The calculated equilibrium β-phase fractions were contrast with the DoS values. Additionally, the influence of the Mg content on corrosion was investigated via potentiodynamic polarization testing, in conjunction with microhardness measurements. We found that Mg additions lead to an increase in hardness without causing any significant impact on electrochemically determined corrosion current density however, Mg content has a major impact on intergranular corrosion as determined from NAMLT.
Publisher: Elsevier BV
Date: 09-2020
Publisher: Association for Materials Protection and Performance (AMPP)
Date: 10-2016
DOI: 10.5006/1637
Publisher: Informa UK Limited
Date: 04-05-2021
Publisher: The Electrochemical Society
Date: 09-2017
Abstract: The corrosion of metallic materials in a given environment depends on the microstructure stemmed from the concurrent influence of the composition, production route, thermomechanical processing, and service conditions. Microstructures and therefore the properties of the alloys produced via high-energy ball milling are known to be significantly different than that produced via conventional techniques even for the same alloy composition. Grain refinement, extended solid solubilities, formation of metastable phases, unique grain boundaries, super saturation of vacancies, high stored energy, increased diffusivities are some of the principle characteristics of the microstructure produced by the high-energy ball milling process. It has been shown recently that development of corrosion resistant light alloys (Al alloys and Mg alloys) is possible by high-energy ball milling in combination with the suitable alloying elements. Al- transition metal alloys have been produced by the high-energy ball milling and subsequent consolidation. X-ray diffraction analysis and scanning electron microscopy indicated significantly higher solid solubility of the transition metals in Al and nanoscale grain refinement. The cyclic potentiodynamic polarization tests revealed significant ennoblement of pitting and repassivation potentials of the high-energy ball milled Al -transition metal alloys. The Grain refinement 100 nm and high solid solubility also increased mechanical strength- compressive yield strength exceeding 1 GPa. High-energy ball milling has been found capable of improving corrosion resistance and strength simultaneously. Mechanisms of the improved corrosion and mechanical properties of the high-energy ball milled alloys will be discussed.
Publisher: Elsevier BV
Date: 07-2018
Publisher: Informa UK Limited
Date: 03-11-2017
Publisher: Elsevier BV
Date: 09-2014
Publisher: The Electrochemical Society
Date: 07-07-2022
DOI: 10.1149/MA2022-01161005MTGABS
Abstract: Characteristics of the passive film and the ability of an alloy to repassivate in any event of passive film breakdown control the corrosion. Studying the passive film has been of great interest since late 1836 when first-time iron was called altered iron. Significant progress in understanding the passive film composition and factors causing breakdown, pit growth and repassivation has been made over the past several decades. However, the role of metallurgical parameters on the passive film structure, composition, crystallinity, chloride ion interaction needs further research attention. The composition and structure of the passive film in Al alloys and stainless steels have been studied using advanced analytical techniques with high depth and spatial resolution have been presented herein. We have used a combination of time of flight secondary ion mass spectrometry (ToF-SIMS), X-ray photoelectron microscopy (XPS), and scanning transmission electron microscopy to study the passive film and pits. The surface film was studied after potentiostatic polarization as well as immersion tests in NaCl solution with immersion time varying from 30 minutes to four weeks. The crystallinity of the passive film was dependent on the composition and microstructure of the alloy. The incorporation of chloride and its distribution in the passive film was dependent on the material and conditions used to produce the passive film. The thickness of the passive film was found to depend on the microstructure of the underlying substrate. The role of the microstructure on passive film structure, breakdown, and repassivation or pit growth will be discussed.
Publisher: Elsevier BV
Date: 12-2022
Publisher: Elsevier BV
Date: 12-2022
Publisher: Elsevier BV
Date: 09-2018
Publisher: CRC Press
Date: 06-04-2023
Publisher: Elsevier BV
Date: 04-2021
Publisher: Elsevier BV
Date: 12-2020
Publisher: Wiley
Date: 25-09-2022
Abstract: The effect of V addition on the hardness and corrosion of aluminum alloy 2024 (AA2024) produced by high‐energy ball milling has been investigated. High‐energy ball milled alloys exhibited enhanced solid solubility of alloying elements and ultrafine grains. The addition of V improved the corrosion resistance of the AA2024 alloy, which was attributed to the deposition of V on the cathodic particles and therefore decrease in their ability to sustain large cathodic currents.
Publisher: MDPI AG
Date: 06-01-2021
Abstract: In this study, a compact cold sprayed (CS) Ti coating was deposited on Mg alloy using a high pressure cold spray (HPCS) system. The wear and corrosion behavior of the CS Ti coating was compared with that of CS Al coating and bare Mg alloy. The Ti coating yielded lower wear rate compared to Al coating and Mg alloy. Electrochemical impedance spectroscopy (EIS) and cyclic potentiodynamic polarization (CPP) tests revealed that CS Ti coating can substantially reduce corrosion rate of AZ31B in chloride containing solutions compared to CS Al coating. Interestingly, Ti-coated Mg alloy demonstrated negative hysteresis loop, depicting repassivation of pits, in contrast to AZ31B and Al-coated AZ31B with positive hysteresis loops where corrosion potential (Ecorr) repassivation potential (Erp) indicating irreversible growth of pits. AZ31B and Al-coated AZ31B were most susceptible to pitting corrosion, while Ti-coated Mg alloy indicated noticeable resistance to pitting in 3.5 wt % NaCl solution. In comparison to Al coating, Ti coating considerably separated the AZ31BMg alloy surface from the corrosive electrolyte during long term immersion test for 11 days.
No related grants have been discovered for Rajeev Gupta.