Mn含量对Mg-Zn-Mn变形镁合金显微组织和力学性能的影响

Effects of Mn Content on Microstructure and Mechanical Properties of Mg-Zn-Mn Wrought Alloys

摘要:

通过对3种不同Mn含量的Mg-6Zn-XMn变形镁合金的微观组织的观察及力学性能的测定，研究了Mn含量对Mg-Zn-Mn镁合金显微组织和力学性能的影响。结果表明：Mn元素以单质形式弥散地分布于Mg-Zn-Mn合金中，起到阻碍晶粒长大的作用，即随着Mn含量的增加，晶粒尺寸减小；Mn含量的变化对合金的屈服强度有一定的影响，即随着Mn含量的增加，屈服强度增加，其中挤压态增幅最大，双级时效次之，增幅分别是14%和5%；而Mn含量的变化对T6、T4+双级时效后合金的抗拉强度和延伸率的影响规律不明显，其中含0.68%Mn(质量分数, 下同)的合金整体性能较优，经双级时效后具有最高抗拉强度，达到360 MPa，伸长率为5.2%

Abstract:

By observing the microstructures and measuring mechanical properties of three kinds of Mg-6Zn-XMn wrought magnesium alloys, the effects of Mn content on microstructures and mechanical properties of Mg-Zn-Mn magnesium alloy was studied. The results show that Mn element distributes dispersively in the matrix mainly as pure Mn particles which can hamper the grain growth, i.e. the grains become finer with Mn content increasing. Mn content has a certain impact on the yield strength of the three alloys, that is, the yield strength increases with Mn content increasing, and the increment of the extruded and the two-stage aged alloys are 14% and 5%, respectively. On the other hand, Mn content has no obvious effect on the tensile strength and elongation of T6 and T4+2-stage aged alloys. The alloy with 0.68wt% Mn after two-stage aging has better overall mechanical properties, whose tensile strength is the highest, 360 MPa, and whose elongation is 5.2%