混合稀土对AZ91合金铸态组织及力学性能的影响

Effect of Mixed Rare Earth on As-Cast Microstructure and Mechanical Properties of AZ91 Alloy

利用SEM、TEM、XRD、WDW3300等仪器设备,研究了混合稀土添加量对AZ91合金铸态组织及力学性能的影响。结果表明:加入稀土元素,AZ91合金的初生相α-Mg和β-Mg17Al12相明显细化,晶粒尺寸变小;合金的力学性能得到提高。当添加量为0.5%时,抗拉强度达到最大值,为167 MPa,比未添加时提高了约17.6%;当添加量为1.5%时,伸长率和硬度达到了峰值,分别为6.2%和62 HBW,比未添加时分别提高了约59%和25.1%。

The effects of addition of mixed rare earth on as cast microstructure and mechanical properties of AZ91 magnesium alloy were studied by using of SEM, TEM, XRD, WDW3300 and other equipment. The results show that the effect is obvious, the effect of rare earth elements can make the primary phase of α-Mg and β- Mg17Al12 phase of AZ91 refine, grain size changed small. The mechanical properties of the alloy were improved. When the addition was 0.5 %, the maximum tensile strength is 167 MPa, which was increased by 17.6 % compared with the alloy without rare earth. When the addition was 1.5 %, elongation and hardness all reached the peak, namely 6.2 % of the elongation and HBW 62 of hardness, and compared with alloy without rare earth they were increased by about 59 % and 25.1%, respectively.