Microstructure and mechanical properties of as-cast Mg-8Sn-1Al-1Zn-xNi alloys
来源期刊：中南大学学报(英文版)2014年第9期
论文作者：QUE Zhong-ping(阙仲萍) MA Teng(马腾) WANG Jian(王剑) CHEN Jin(陈津) WANG Cai-hong(王彩虹) CHENG Wei-li(程伟丽)
文章页码：3426 - 3433
Key words：Mg-Sn-Al-Zn alloy; Ni; microstructure; mechanical properties
Abstract: Mg-8Sn-1Al-1Zn-xNi (x=0.5%, 1.0%, 1.5%, 2.0%, mass fraction) alloys were designed and prepared. The microstructures and the mechanical properties were studied by using optical microscope, scanning electronic microscope, energy dispersive X-ray spectroscope, X-ray diffraction and a standard universal testing machine. The results show that the microstructure of Ni-containing alloys consist of α-Mg, Mg2Sn, β-Mg-Ni-Al and γ-AlNi phases. No β-Mg-Ni-Al phase was observed in TAZ811-2.0Ni alloy due to its 1:1 atomic ratio of Ni/Al. The addition of Ni refines the α-Mg dendrites and suppresses the formation of coarse Mg2Sn phase. The tensile properties results show that the TAZ811-0.5Ni alloy presented the best mechanical properties, which is due to the rod-like β-Mg-Ni-Al phase, refined α-Mg dendrites and Mg2Sn phase, as well as γ-AlNi phase. The tensile fracture mechanism transits from cleavage to quasi-cleavage fracture with the increasing Ni addition.
QUE Zhong-ping(阙仲萍), MA Teng(马腾), WANG Jian(王剑), CHEN Jin(陈津), WANG Cai-hong(王彩虹), CHENG Wei-li(程伟丽)
(School of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, China)
Abstract:Mg-8Sn-1Al-1Zn-xNi (x=0.5%, 1.0%, 1.5%, 2.0%, mass fraction) alloys were designed and prepared. The microstructures and the mechanical properties were studied by using optical microscope, scanning electronic microscope, energy dispersive X-ray spectroscope, X-ray diffraction and a standard universal testing machine. The results show that the microstructure of Ni-containing alloys consist of α-Mg, Mg2Sn, β-Mg-Ni-Al and γ-AlNi phases. No β-Mg-Ni-Al phase was observed in TAZ811-2.0Ni alloy due to its 1:1 atomic ratio of Ni/Al. The addition of Ni refines the α-Mg dendrites and suppresses the formation of coarse Mg2Sn phase. The tensile properties results show that the TAZ811-0.5Ni alloy presented the best mechanical properties, which is due to the rod-like β-Mg-Ni-Al phase, refined α-Mg dendrites and Mg2Sn phase, as well as γ-AlNi phase. The tensile fracture mechanism transits from cleavage to quasi-cleavage fracture with the increasing Ni addition.
Key words:Mg-Sn-Al-Zn alloy; Ni; microstructure; mechanical properties
