ORCID Profile
0000-0003-1913-8301
Current Organisations
University of Queensland
,
Northeastern University
,
CSIRO
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Publisher: MDPI AG
Date: 16-05-2017
DOI: 10.3390/MET7050173
Abstract: Traditional fixed-frequency ultrasonic technology and a variable-frequency ultrasonic technology were applied to refine the as-cast microstructure and improve the mechanical properties of a ZK60 (Mg–Zn–Zr) alloy during large diameter semi-continuous casting. The acoustic field propagation was obtained by numerical simulation. The microstructure of the as-cast s les was characterized by optical and scanning electron microscopy. The variable-frequency ultrasonic technology shows its outstanding ability in grain refinement compared with traditional fixed-ultrasonic technology. The variable-frequency acoustic field promoted the formation of small α-Mg globular grains and changed the distribution and morphology of β-phases throughout the castings. Ultimate tensile strength and elongation are increased to 280 MPa and 8.9%, respectively, which are 19.1% and 45.9% higher than the values obtained from billets without ultrasonic treatment and are 11.6% and 18.7% higher than fixed-frequency ultrasound treated billets. Different refinement efficiencies appear in different districts of billets attributed to the sound attenuation in melt. The variable-frequency acoustic field improves the refinement effect by enhancing cavitation-enhanced heterogeneous nucleation and dendrite fragmentation effects.
Publisher: Hindawi Limited
Date: 09-06-2020
DOI: 10.1002/ER.5595
Publisher: IOP Publishing
Date: 25-05-2018
Publisher: Elsevier BV
Date: 11-2022
Publisher: Springer Science and Business Media LLC
Date: 18-03-2019
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1TA01471D
Abstract: A comprehensive review of the development of magnesium anodes for primary batteries. Excellent guidance for both beginners and veterans in this field.
Publisher: Elsevier BV
Date: 08-2023
Publisher: Springer Science and Business Media LLC
Date: 11-06-2022
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1TA04320J
Abstract: This work used both experiments and modeling methods to understand some critical issues of ultra-high-purity (UHP) Mg discharge behavior for Mg–air primary batteries.
Publisher: Elsevier BV
Date: 04-2023
Publisher: Elsevier BV
Date: 08-2023
Publisher: Springer Science and Business Media LLC
Date: 26-05-2022
Publisher: Elsevier BV
Date: 05-2023
Publisher: Elsevier BV
Date: 02-2022
Publisher: Elsevier BV
Date: 11-2021
Publisher: Elsevier BV
Date: 03-2020
Publisher: Elsevier BV
Date: 07-2020
Publisher: Hindawi Limited
Date: 06-07-2022
DOI: 10.1002/ER.8354
Publisher: Elsevier BV
Date: 09-2019
Publisher: Elsevier BV
Date: 04-2022
Publisher: MDPI AG
Date: 04-11-2022
Abstract: The cooling characteristic curves in a heated ingot with a diameter of 100 mm quenched by a water jet were measured under different conditions. A two-dimensional calculation model was established to calculate the HTC of magnesium alloy ingot with water spray cooling. Data from cast-in thermocouples trail were input into the model and the HTCs were back-calculated for the water quench region. The HTCs were calculated under different alloy types and roughness conditions, and the relationship between the ingot surface temperature, roughness, and the HTC was established accordingly. The results show that the greater the thermal conductivity of the alloy, the greater the heat transfer coefficient (HTC). The HTCs of AZ80, AZ31, and ZK60 alloys increase successively. With the decrease in the surface temperature, the HTC in both the impingement zone and the free−falling zone shows a trend of a rapid increase at first, then slowly increasing to the maximum value, and finally, a rapid decrease, with the peak value appearing at about 400 K. Considering the influence of the ingot surface temperature and the surface roughness on the HTC, the mathematical relationships between them are established.
Publisher: Springer Science and Business Media LLC
Date: 06-05-2019
Publisher: Elsevier BV
Date: 06-2020
Publisher: Elsevier BV
Date: 08-2021
Publisher: MDPI AG
Date: 19-05-2023
Abstract: Conventional billet rolling is being widely used in magnesium (Mg) alloys products, but this method gives rise to biological and environmental problems. The advantages of the short process on sheet fabrication have been widely proved in Mg alloy twin-roll casting (TRC). In this study, an attempt is made to create high-performance Mg alloy sheets via multi-pass unidirectional and cross hot rolling (UR, CR) after TRC for purposes of lowering edge defects and energy consumption. Then, the microstructural and mechanical response of Ce when microalloying AZ31 was observed using UR and CR, respectively. The mechanism of the performance improvement after the AZ31 microalloying is disclosed. In addition, the effect of the rolling parameters on the microstructural and mechanical properties are discussed. Experimental results revealed that the homogenization effect of the AZ31-0.2Ce alloy was the best after being kept at 440 °C for 24 h. The CR-rolled sheet had a more uniform and finer microstructure in the horizontal and center, while for the UR-rolled sheet, it was the opposing edge microstructure. This research is expected to prepare and optimize the microstructural and mechanical properties of microalloying AZ31 in a sheet-rolling process, a material that has important theoretical significance and engineering application value.
Publisher: Hindawi Limited
Date: 09-09-2022
DOI: 10.1002/ER.8703
Publisher: Elsevier BV
Date: 2022
Publisher: Trans Tech Publications, Ltd.
Date: 09-2019
DOI: 10.4028/WWW.SCIENTIFIC.NET/KEM.821.209
Abstract: The traditional fixed-frequency ultrasonic technology (FUT) and the variable-frequency ultrasonic technology (VUT) were used in direct-chill (DC) casting of an AZ80 magnesium alloy with the diameter of ∅255mm. The microstructure evolution, mechanical properties and macro-segment of Al element were investigated. The results show that both FUT and VUT can refine the α-Mg grain while the VUT has better efficiency which can reduce the grain size from 679-1454 μm (DC) to 150-241 μm. The homogeneity of grain size was also improved. These two technologies can also change the morphology and distribution of Mg 17 Al 12 phase and tiny and refined morphology of Mg 17 Al 12 phase and a homogeneous distribution can be obtained after VUT treatment. The YS and UTS were increased following the microstructure evolution, displaying the YS of 88.9-95.1 MPa and UTS of 164.3-173.1 MPa after VUT treatment. The segregation rate of Al element were improved with VUT treatment. Keywords: magnesium alloy variable frequency ultrasonic technology microstructure mechanical properties
Publisher: MDPI AG
Date: 27-02-2023
Abstract: In the process of open-roller conveying, magnesium alloy plates easily produce temperature drops and uneven temperatures. Ignoring the heat dissipation caused by the contact between the plate and the roller table, the process can be described as a process of air cooling. The present study aimed to investigate the temperature distribution and evolution of a magnesium alloy plate during the process. The air-cooling process of the AZ31B magnesium alloy plate was investigated and analyzed in detail under different initial temperatures and plate thicknesses, with a specific focus on the temperature distribution along both the width and thickness directions. The results show that the temperature-difference curves between the end face and the center under different air-cooling conditions appeared to have four stages: rapid increase, slow increase, basic stable and slow decline. To facilitate the establishment of the temperature model, the whole air-cooling process was approximately ided into two independent one-dimensional heat-conduction processes in the thickness direction and the width direction. Subsequently, one-dimensional steady-state heat-conduction models were developed in various directions, based on the fundamental principles of heat transfer and assuming that the adjacent temperature-drop layer satisfied the quadratic function distribution. Through the superposition of cooling with time in two directions, the temperature evolution at different positions in the process of air cooling can be solved accurately.
Publisher: Springer Science and Business Media LLC
Date: 02-10-2021
Publisher: Springer Science and Business Media LLC
Date: 08-11-2021
Publisher: Springer Science and Business Media LLC
Date: 11-03-2019
Publisher: Elsevier BV
Date: 02-2019
Publisher: IOP Publishing
Date: 05-06-2019
Publisher: Elsevier BV
Date: 11-2021
Publisher: Elsevier BV
Date: 07-2020
Publisher: Elsevier BV
Date: 2020
Publisher: Elsevier BV
Date: 11-2019
Publisher: MDPI AG
Date: 12-10-2017
DOI: 10.3390/MA10101167
Publisher: Elsevier BV
Date: 10-2019
Publisher: IntechOpen
Date: 25-03-2019
Publisher: Elsevier BV
Date: 04-2019
Publisher: Elsevier BV
Date: 2021
Publisher: Elsevier BV
Date: 05-2020
Publisher: MDPI AG
Date: 25-10-2022
Abstract: The secondary cooling of AZ80 during DC casting was investigated by measuring the temperature at a given position during steady state. The experiment was carried out under different parameters including the water flow rate density (Q*) and initial temperature (Ti) of the impingement points. To theorize the heat transfer of the secondary cooling zone in practical DC casting, we designed a series of experimental equipment to simulate the secondary cooling with differing Ti (between 473 and 673 K) and Q* (between 20 and 100 L min−1 m−1) based on the DC casting temperature-measurement experiment above. Detailed analysis was carried out of both the experimental results combined with Q*. The empirical formulae of Rohsenow and Weckman were modified due to the need to ide the secondary cooling zone into an impingement zone and a free-falling zone. Finally, a verification of the model’s accuracy was conducted by comparing the results of the finite volume numerical simulation and the experiment, which revealed that the model exhibited extremely high accuracy.
Publisher: Springer Science and Business Media LLC
Date: 14-05-2020
Publisher: Elsevier BV
Date: 2018
DOI: 10.1016/J.ULTSONCH.2017.07.027
Abstract: Compared with other dual-frequency acoustic applications, melt-treatment with dual-frequency ultrasound was less researched, especially in magnesium field. In this present work, traditional single-frequency ultrasonic field (SUF) treatment and dual-frequency ultrasonic field (DUF) treatment were used to refine the as-cast microstructure and improve the mechanical properties of the ZK60 (Mg-Zn-Zr) magnesium alloy. The influences of DUF on the microstructure evolution and mechanical properties were systematically investigated, and the cavitation bubble's dynamic behaviors were investigated by numerical simulation. α-Mg grains and second phases were dramatically refined by introduced ultrasound, and DUF showed higher refinement efficiency than SUF. The DUF treatment promoted the formation of small α-Mg globular grains and changed the distribution and morphology of MgZn
Publisher: Elsevier BV
Date: 03-2022
Publisher: Elsevier BV
Date: 02-2020
Publisher: Elsevier BV
Date: 04-2020
Publisher: Elsevier BV
Date: 09-2020
Publisher: Elsevier BV
Date: 02-2019
Publisher: Elsevier BV
Date: 07-2021
Publisher: IOP Publishing
Date: 04-2021
Abstract: This work investigated the discharge properties of the Mg-6Al-xCd alloy as a potential anode material for the Mg–air battery. The influence of the Mg-6Al-xCd alloy with cadmium content ranging between 0.5% and 1% on the electrochemical and discharge performances was investigated by means of microstructure characterization, electrochemical performance measurement and discharge test of the alloys. The results show that Mg-6Al-1.0Cd has the highest anode efficiency and specific capacity of 41.38% and 993.54 mAh/g, respectively. This good discharge performance is attributed to the addition of cadmium, which can inhibit self-corrosion and reduce the galvanic corrosion of the magnesium anode. The Mg-6Al-1.0Cd alloy can be used as a potentially ideal material for the Mg–air battery anode.
Publisher: Elsevier BV
Date: 2021
Publisher: MDPI AG
Date: 29-09-2022
DOI: 10.3390/CMD3040031
Abstract: Recent progress is reviewed. Recent developments include: (i) accumulation of evidence that electrochemical measurements of the Mg corrosion rate often do not agree with the steady state Mg corrosion rate as measured by weight loss (ii) low Fe tolerance limits are caused by heat treatment of nominally high-purity Mg and the presence of Si, (iii) the intrinsic Mg corrosion rate is 0.3 mm/y in a chloride solution as measured by weight loss, (iv) there are many Mg alloys with corrosion rates between 0.3 and 1.0 mm/y, (v) there are few Mg alloys with corrosion rates less than 0.3 mm/y, (vi) experimental evidence contradicts the enhanced catalytic activity mechanism of Mg corrosion, (vii) experiments support the uni-positive Mg+ mechanism, (viii) new compelling experimental evidence supporting the uni-positive Mg+ corrosion mechanism has been provided by electrochemical impedance spectroscopy (EIS), and (ix) the uni-positive Mg+ corrosion mechanism provides new insights for understanding the performance of Mg-air batteries and for the development of better Mg anodes.
Publisher: Elsevier BV
Date: 08-2020
Publisher: Springer Science and Business Media LLC
Date: 06-05-2021
Publisher: Elsevier BV
Date: 09-2021
Publisher: Elsevier BV
Date: 11-2021
Publisher: CRC Press
Date: 17-02-2023
Publisher: IOP Publishing
Date: 21-09-2018
No related grants have been discovered for Xingrui Chen.