等通道转角挤压对Mg-6Zn合金显微组织和力学性能的影响  

Effects of Equal Channel Angular Pressing on Microstructure and Mechanical Properties of Mg-6Zn Alloy

作　　者：费洪旗 严凯[1] 金朝阳[1] 程宏辉[1] 宋奎[1] 

机构地区：[1]扬州大学机械工程学院,江苏扬州225127

出　　处：《热加工工艺》2017年第13期76-79,共4页Hot Working Technology

摘　　要：利用等通道转角挤压(ECAP)技术,在200℃对Mg-6Zn合金进行了不同道次的挤压。结果表明,经ECAP挤压后合金显微组织明显细化、均匀化,平均晶粒尺寸由15μm减小到3μm;ECAP过程中粗大的块状共晶相变形破碎、细化,并在周围诱发新相析出。通过XRD分析发现析出相主要是Mg_4Zn_7和MgZn_2。经过2道次ECAP挤压后,Mg-6Zn合金的抗拉强度可达275 MPa,屈服强度达到245 MPa,伸长率为24%。当ECAP道次增加到4道次和6道次后,强度反而下降。Mg-6Zn alloy at 200 ℃ was extruded in different times by using equal channel angular pressing （ECAP） technique. The results show that the microstrueture of the alloy is refined and homogenized after ECAP extrusion, and the average grain size decreases from 15 μm to 3 μm; in the process of ECAP, the massive eutectic phases are broken and refined, and the new phase precipitates around eutectic phases. XRD analysis reveals that the precipitates are mainly Mg4Zn7 phase and MgZn2 phase. After 2 times of ECAP extrusion, the tensile strength, the yield strength and the elongation of Mg -6Zn alloy reach to 275 MPa, 245 MPa and 24%, respectively. When the ECAP increases to 4 times and 6 times, the strength decreases.

关 键 词：Mg-6Zn合金 显微组织 力学性能 等通道转角挤压 形变诱发析出 

分 类 号：TG376[金属学及工艺—金属压力加工]