Microstructures and mechanical properties of double hot-extruded AZ80+xSr wrought alloys
The effects of Sr addition on microstructures and tensile properties of the as-cast and hot-extruded AZ80 alloys were studied by OM,SEM,EDS,XRD,DSC and Instron tester.The results show that the microstructures of as-cast alloys consist of α-Mg and β-Mg17Al12 phase.Sr gathers on the boundaries,and dissolves into β-Mg17Al12 phase or forms Mg17Sr2 phase.The grains of as-cast alloys are refined and discontinuous net-shaped structure is formed.The compound phases on the boundaries become thicker with increasing Sr content.The ultimate tensile stress(UTS) and elongation are improved compared with the corresponding Sr-free alloy.After preliminary hot-extruding,the UTS is up to 308.320 MPa and elongation reaches 8.0％.13.5％.After double hot-extrusion,the dynamic recrystallization completes totally,and the UTS is up to 310.355 MPa,but the elongation does not change apparently.The alloy with 0.02％Sr (mass fraction) obtains the best comprehensive performance with the UTS of 355 MPa and elongation of 13.2％.The SEM morphology of fracture surface shows that the alloys with Sr present good ductility after double hot-extrusion.
AZ80 magnesium alloy Sr double hot-extrusion ultimate tensile strength elongation
GUAN Shao-kang ZHU Shi-jie WANG Li-guo YANG Qing CAO Wen-bo
School of Materials Science and Engineering,Zhengzhou University,Zhengzhou 450002,China Received 15 July 2007;accepted 10 September 2007
国际会议
2007年国际有色金属大会(International Conference of Nonfereous Materials 2007)(ICNFM)
长沙
英文
2007-11-28（万方平台首次上网日期，不代表论文的发表时间）