铸态Mg-11Al-1.2Zn-(-0.3Sc)合金的显微组织与力学性能

Microstructuse and Mechanical Properties of Mg-11Al-1.2Zn-(-0.3Sc) Alloy

通过熔炼铸造方法,制备了Sc含量为0.3%的Mg-11Al-1.2Zn合金,采用X射线衍射、金相观察、扫描电镜及力学性能测试,研究了Sc的添加对铸态合金显微组织与力学性能的影响。结果显示,基体合金中添加Sc后,铸态合金的晶粒明显得到细化,Mg17Al12相的形态与分布得到有效改善,显微组织主要由α-Mg基体相、Mg17Al12相及MgAlSc相组成。力学性能显示,Sc的添加使铸态合金的室温抗拉强度提高了23.7%。

Mg-11Al-1.2Zn alloys containing 0.3% Sc were prepared by ingot metallurgy. The effects of scandium addition on the mechanical properties and microstructure of the as-cast alloy have been investigated by X-ray diffraction(XRD),optical microscope(OM),scanning electron microscope (SEM) and tensile testing. The results indicate that the microstructure of the alloys is mainly composed of primary α-Mg phase,Mg17Al12 phase and MgAlSc phase,in which the grain size and morphology and distribution of Mg17Al12 phase can be evidently improved with Sc addition. In addition,the tensile strength of the alloy at room temperature can be increased by more than 10% with the Sc addition.