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Effect of Heat-treatment on the Microstructures and Mechanical Properties of Mg-10Zn-5Al-0.1Sb-xCu Magnesium Alloy

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Journal of Wuhan University of Technology(Materials Science) 2013年第4期28卷 834-839页

作者：游志勇 ZHANG Yuhua cheng weili ZHANG Jinshan WEI Yinghui College of Materials Science and Engineering Taiyuan University of Technology

The effects of the solution and aging treatment on microstructures and mechanical properties of the Mg-10Zn-5A1-0.1Sb-XCu cast magnesium alloys were investigated by brinell hardness measurement, scanning electron microscopy （SEM）, energy spectrum analyzing apparatus and X-ray diffraction （XRD）. The experimental results show that the strip-like t-Mg32 （A1, Zn）49 phase is shown at the grain boundaries and Mg2Cu phase become smaller, even granular after solution treatment at 350 ~C for 24 h. By ageing treatment at 180 ~C, the ternary strengthening phase （r phase） precipitates gradually at or around grain boundary. With increasing aging time, the micro-hardness improves obviously and up to the maximum （105.9 HV） at aging time of 36 h. In addition, the tensile-strengths at room temperature and at an elevated temperature respectively reach 228 MPa and 176 MPa, which is increased by 20% and 10%, respectively.

关键词： solution and aging magnesium alloy microstructure mechanical property

Hot deformation behavior and workability characteristic of a fine-grained Mg–8Sn–2Zn–2Al alloy with processing map

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Journal of Materials Science & Technology 2019年第6期35卷 1198-1209页

作者： weili cheng Yang Bai Shichao Ma Lifei Wang Hongxia Wang Hui Yu Shanxi key Laboratory of Advanced Magnesium-Based Materials Taiyuan University of Technology Taiyuan 030024 China Key Laboratory of Interface Science and Engineering in Advanced Materials Ministry of Education Taiyuan University of Technology Taiyuan 030024China School of Materials Science and Engineering Taiyuan University of Technology Taiyuan 030024 China School of Materials Science and Engineering Hebei University of Technology Tianjin 300132 China

The hot deformation behavior of a fine-grained Mg–8 Sn–2 Zn–2 Al(TZA822, in wt%) alloy was investigated in the temperature range of 150–350°C and the strain rate of 0.01–10 s^-1 employing thermomechanical simulator. In most of the cases, the material showed typical dynamic recrystallization(DRX) features i.e., a signal peak value followed by a gradual decrease or to reach a steady state. The work hardening rate was found to increase with decreasing temperature and increasing strain rate, while strain rates had great effects on work hardening behavior. Meanwhile, the constitutive analysis indicated that cross-slip of dislocations was likely to be the dominant deformation mechanism. In addition, the processing map at the strain of 0.1–0.7 showed two stability domains with high power dissipation efficiencies and the optimum hot working parameters for the studied alloy was determined to be 350°C/0.01 s^-1 and 350°C/10 s^-1, at which continuous DRX(CDRX) and discontinuous DRX(DDRX) as main softening mechanism. The instability regions occurred at 200–250°C/10 s^-1 and the main flow instability mechanism was twinning and/or flow localization bands, which were prone to induce cracks and caused in-consistent mechanical properties of the alloy.

关键词： Mg-Sn based alloy Hot deformation Processing map Dynamic recrystallization

Effects of Ce addition on microstructure, mechanical properties and corrosion resistance of as-cast AZ80 magnesium alloy

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China Foundry 2014年第3期11卷 157-162页

作者： Wang Wei Xu Chunxiang Zhang Jinshan cheng weili Niu Xiaofeng College of Materials Science and Engineering Taiyuan University of Technology

In this study, Ce was introduced into the AZ80 alloy and the effects of Ce addition on the microstructure, mechanical properties and corrosion resistance of the as-cast AZ80 magnesium alloy were investigated. The results show that the addition of Ce into the AZ80 alloy can not only refine the microstructure, but also result in the formation of the needle-like Al4Ce phase. These tiny Al4Ce phases are homogeneously distributed at grain boundaries and within grains. An appropriate Ce addition can also change the β-Mg17Al12 phase at the grain boundaries from continuous network to small island-like. At the same time, with the increase of Ce content from 0 to 2.0wt.%, the macro-hardness of the as-cast alloy is enhanced linearly, while impact toughness, tensile strength and elongation all firstly increase and then decrease. The AZ80 alloy containing 1.0wt.% Ce exhibits the optimal properties. Its macro-hardness, impact toughness, tensile strength and elongation are 61.90 HB, 15.50 J·cm-2, 171.80 MPa and 3.35%, increase by 9.95%, 63%, 13.3% and 36.7%, respectively compared with the base alloy. In addition, Ce can enhance the corrosion resistance of the AZ80 magnesium alloy.

关键词： Ce AZ80 magnesium alloy microstructure mechanical properties corrosion resistance

A High Gain, Noise Cancelling 2515-4900 MHz CMOS LNA for China Mobile 5G Communication Application

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Computers, Materials & Continua 2020年第8期64卷 1139-1151页

作者： Xiaorong Zhao weili cheng Hongjin Zhu Chunpeng Ge Gengyuan Zhou Zhongjun Fu College of Computer Engineering Jiangsu University of TechnologyChangzhou213001China Jiangsu Agri-Animal Husbandry Vocational College Taizhou225300China University of Wollongong WollongongNSW 2522Australia

With the development of the times,people’s requirements for communication technology are becoming higher and higher.4G communication technology has been unable to meet development needs,and 5G communication technology has emerged as the times *** article proposes the design of a low-noise amplifier(LNA)that will be used in the 5G band of China Mobile Communications.A low noise amplifier for mobile 5G communication is designed based on Taiwan Semiconductor Manufacturing Company(TSMC)0.13μm Radio Frequency(RF)Complementary Metal Oxide Semiconductor(CMOS)*** LNA employs self-cascode devices in current-reuse configuration to enable lower supply voltage operation without compromising the *** design uses an active feedback amplifier to achieve input impedance matching,avoiding the introduction of resistive negative feedback to reduce gain.A common source(CS)amplifier is used as the input of the low noise *** order to achieve the low power consumption of LNA,current reuse technology is used to reduce power *** cancellation techniques are used to eliminate *** simulation results in a maximum power gain of 22.783,the reverse isolation(S12)less than-48.092 dB,noise figure(NF)less than 1.878 dB,minimum noise figure(NFmin)=1.203 dB,input return loss(S11)and output return loss(S22)are both less than-14.933 dB in the frequency range of 2515-4900 *** proposed Ultra-wideband(UWB)LNA consumed 1.424 mW without buffer from a 1.2 V power supply.

关键词： Common source low noise amplifier current reuse noise cancelling

Texture evolution induced by twinning and dynamic recrystallization in dilute Mg-1Sn-1Zn-1Al alloy during hot compression

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Journal of Magnesium and Alloys 2020年第3期8卷 899-909页

作者： Meijuan Hao weili cheng Lifei Wang Ehsan Mostaed Liping Bian Hongxia Wang Xiaofeng Niu School of Materials Science and Engineering Taiyuan University of TechnologyTaiyuan 030024China Shanxi Key Laboratory of Advanced Magnesium-Based Materials Taiyuan University of TechnologyTaiyuan 030024China Department of Materials Science and Engineering Michigan Technological UniversityHoughtonMI 49931USA

Texture evolution of an extruded dilute Mg-1Sn-1Zn-1Al alloy was thoroughly investigated based on the twinning and dynamic recrystallization(DRX)behavior via hot compression at a strain rate of 10 s^(-1)and temperature of 225℃.It was found that the types and intensities of the texture are strongly dependent on the fraction of twins and DRX modes as well as regions where sub-grain boundaries(sub-GBs)are intensively *** the initial stage of deformation,the formation of compression direction(CD)-tilted basal texture was mainly determined by the occurrence of{101^(-)2}extension *** the strain increases,the variation in the texture intensity was greatly dominated by the DRX modes but the type of main texture remained *** findings are of great importance for texture modification of wrought Mg-Sn-based alloys during post-deformation.

关键词： Mg-1Sn-1Zn-1Al Hot deformation Twinning Dynamic recrystallization Texture

In vitro evaluation of Zn-10Mg-xHA composites with the core-shell structure

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Frontiers of Materials Science 2024年第3期18卷 19-33页

作者： Zeqin Cui Qifeng Hu Jianzhong Wang Lei Zhou Xiaohu Hao Wenxian Wang Weiguo Li weili cheng cheng Chang College of Materials Science and Engineering Taiyuan University of TechnologyTaiyuan 030024China Shanxi-Zheda Institute of Advanced Materials and Chemical Engineering Taiyuan 030000China State Key Laboratory of Porous Metal Materials Northwest Institute for Non-ferrous Metal ResearchXi'an 710016China Engineering Training Center Taiyuan University of TechnologyTaiyuan 030024China Guangdong Provincial Key Laboratory of Modern Surface Engineering Technology National Engineering Laboratory of Modern Materials Surface Engineering TechnologyInstitute of New MaterialsGuangdong Academy of SciencesGuangzhou 510651China

Zinc-based composites represent promising materials for orthopedic implants owing to their adjustable degradation rates and excellent *** this study,a series of Zn-10Mg-xHA(x=0-5 wt.%)composites with the core-shell structure were prepared through spark plasma sintering,and their microstructural,mechanical,and in vitro properties were systematically *** showed that the doped hydroxyapatite(HA)is concentrated at the outer edge of the MgZn2 shell *** compression strength of the Zn-1oMg HA composite gradually decreased with the increase of the HA content,while its corrosion rate decreased initially and then *** corrosion resistance of the composite with the addition of 1 wt.%HA was improved compared to that of ***,the further increase of the HA content beyond 1 wt.%resulted in a faster degradation of the ***,the Zn-10Mg-1HA composite significantly enhanced the activity of Mc3T3-E1 *** on such findings,it is revealed that the composite containing 1 wt.%HA exhibits superior overall properties and is anticipated to serve as a promising candidate for bone implantmaterials.

关键词： zinc-based composite hydroxyapatite mechanical property in vitro degradationbehavior biocompatibility

Enhanced mechanical properties of LPSOp/Mg composites using super high pressure treatment

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Journal of Rare Earths 2024年第12期42卷 2249-2258页

作者： Wei Yu Zhongjie Li Chao Liu Qiuming Peng weili cheng Huashun Yu Kwang Seon Shin Hui Yu School of Materials Science and Engineering Hefei University of Technology School of Materials Science and Engineering Shandong University Tianjin Key Laboratory of Materials Laminating Fabrication and Interfacial Controlling Technology School of Materials Science and Engineering Hebei University of Technology State Key Laboratory of Metastable Materials Science and Technology Yanshan University School of Materials Science and Engineering Taiyuan University of Technology Magnesium Technology Innovation Center Seoul National University

The super high pressure（SHP） technique was employed to fabricate the magnesium matrix composites（MMCs） reinforced with long-period stacking order structure powder（LPSOp） by cubic-anvil large-volume press with six rams. The LPSOp was optimized through high energy ball milling（HEBM） with a chemical composition of Mg85Zn6Y9（at%）. The microstructure and mechanical properties of LPSOp/Mg composite was characterized by X-ray diffraction（XRD）, scanning electron microscopy/transmission electron microscopy（SEM/EDS）, transmission electron microscopy（TEM）, microhardness and compressive tests. The microhardness of LPSOp exhibits a notable increase after HEBM, and the thermal stability of LPSOp is affirmed through elevated annealing. The SHPed LPSOp/Mg consists of Mg and LPSO phase. Upon annealing at 400℃ for 1 h, the LPSO phase precipitates from solid solution of Mg and W phase is also identified. The strength of composites by SHP treatment and subsequently annealing is significantly improved compared with the pure Mg without LPSOp, which demonstrates the maximum compression yield strength（CYS） of 250 MPa and ultimate compression strength（UCS） of 375 MPa with satisfactory ductility. The enhanced mechanical properties are attributed to the synergistic reinforcement effects of the dispersed and 3D skeletal structure of LPSOp with excellent interfacial bonding, the coexistence of nano-scale LPSO and W phase and partial solid solution strengthening.

关键词： Long-period stacking ordered Mechanical property Mg composite Microstructure Rare earths Super-high pressure

Effect of Cu addition on microstructure and properties of Mg-10Zn-5Al-0.1Sb high zinc magnesium alloy

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China Foundry 2012年第1期9卷 43-47页

作者： You Zhiyong Zhang Yuhua cheng weili Zhang Jinshan Wei Yinghui College of Materials Science and Engineering Taiyuan University of TechnologyTaiyuan 030024ShanxiChina

To improve the strength, hardness and heat resistance of Mg-Zn based alloys, the effects of Cu addition on the as-cast microstructure and mechanical properties of Mg-10Zn-5Al-0.1Sb high zinc magnesium alloy were investigated by means of Brinell hardness measurement, scanning electron microscopy （SEM）, energy dispersive spectroscopy （EDS）, XRD and tensile tests at room and elevated temperatures. The results show that the microstructure of as-cast Mg-10Zn-5AI-0.1Sb alloy is composed of α-Mg, τ-Mg32（Al, Zn）49, Ф-Al2MgsZn2 and Mg3Sb2 phases. The morphologies of these phases in the Cu-containing alloys change from semi-continuous long strip to black herringbone as well as particle-like shapes with increasing Cu content. When the addition of Cu is over 1.0wt.%, the formation of a new thermally-stable Mg2Cu phase can be observed. The Brinell hardness, room temperature and elevated temperature strengths firstly increase and then decrease as the Cu content increases. Among the Cucontaining alloys, the alloy with the addition of 2.0wt.% Cu exhibits the optimum mechanical properties. Its hardness and strengths at room and elevated temperatures are 79.35 HB, 190 MPa and 160 MPa, which are increased by 9.65%, 21.1% and 14.3%, respectively compared with those of the Cu-free one. After T6 heat treatment, the strengths at room and elevated temperatures are improved by 20% and 10%, respectively compared with those of the ascast alloy. This research results provide a new way for strengthening of magnesium alloys at room and elevated temperatures, and a method of producing thermally-stable Mg-10Zn-5Al based high zinc magnesium alloys.

关键词： microstructure mechanical properties high zinc magnesium alloy Mg2Cu phase

Synthesis of 5-（Sulfamoylmethyl）indoles by Mild Negishi Coupling and Their Application in Almotriptan

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Chemical Research in Chinese Universities 2015年第4期31卷 539-542页

作者： LI Xiaolong QIU Rui WAN weili cheng Xu HE Yi HAI Li WUYong Key Laboratory of Drug-Targeting and Drug-Delivery Systems of Ministry of Education Department of Medicinal Chemistry West China School of Pharmacy Sichuan University Chengdu 610041 P R. China

A new synthetic route of almotriptan was described. The application of Negishi coupling reaction simpli- fied the process and significantly improved the yield. The synthetic route was also expected to be general for t... 详细信息

关键词： Negishi coupling Almotriptan 5-(Sulfamoylmethyl)indole