大尺寸镁-锌-锆合金挤压型材组织、织构和力学性能的研究(英文)

Microstructure, Texture and Mechanical Properties of Extruded Mg-Zn-Zr Mg Alloy Profiles

通过X射线衍射分析、金相分析和力学性能测试对大尺寸ZK60镁合金挤压型材的微观组织、织构取向和室温力学性能进行系统研究。结果显示,挤压态ZK60镁合金中主要由α-Mg和Mg Zn2相组成,此外还有少量的Mg2Zn11和Zn2Zr3相。挤压变形后初始的粗大铸态组织沿着挤压方向被极大地细化和破碎,同时伴有部分动态再结晶发生。大部分晶粒的基面沿着挤压方向和横向排列而不是常规的挤压纤维状取向分布。沿着45o方向取样展现出最好的断裂伸长率,其中间和边部分别为28%和23%,而最大抗力强度则体现在沿着挤压方向拉伸样品在中间和边部分别为325和312 MPa。

The microstructures, texture and mechanical properties of large scale ZK60 magnesium alloy profiles were systematically investigated by XRD diffraction, microstructure observation and tensile testing at room temperature. The results indicate that there are mainly two phases in the extruded ZK60 Mg alloy, i.e. a-Mg and MgZn2, while a small amount of Mg2Znll and Zn2Zr3 phases were also observed. Initial coarse grains were significantly refined and broken down along the extrusion direction （ED）, and partially dynamic recrystallization （DRX） also takes place during the hot extrusion process. The basal plane in most grains is aligned to ED and transverse direction （TD） rather than commonly extruded fiber texture. In the tensile test, the samples of 45ED direction exhibit the highest elongation to failure （δ=28% and 23%）, and the ED direction reveal the highest ultimate tensile strength （σb =325 MPa and 312 MPa） along middle and side parts, respectively.