Nd改性AZ91合金的显微组织和力学性能

Effects of Different Nd Content on Microstructure and Mechanical properties of AZ91 Alloy

稀土Nd加入AZ91合金中可生成Al-Nd相并细化合金晶粒。Nd含量影响合金中Al-Nd相的种类、形貌、大小和分布,从而改变合金的室温拉伸力学性能。当Nd含量为1.0%时,合金中析出的Al-Nd相主要为针状的Al11Nd3相;当Nd含量为到2.0%时,针状的Al11Nd3相已经比较少,块状的Al2Nd相为主要的Al-Nd相;当Nd含量为到2.5%时,析出的Al-Nd相几乎全部为块状的Al2Nd相。Nd含量由1.0%增加到2.0%时,合金的伸长率、抗拉强度和屈服强度分别增加33%、14%和4%;Nd含量由1.0%增加到2.5%时,上述三者分别增加44%、18%和6%。

Al-Nd phase can be generated and the grain can be refined in the AZ91 magnesium alloy with Nd addition. The tensile strength at room temperature of the alloy can be improved due to Nd content affecting the type,morphology,size and distribution of Al-Nd phase. Acicular Al11Nd3 phase is major in the alloy with 1.0% Nd addition,and bulk Al2Nd phase is obviously increased with acicular Al11Nd3 phase reduction in the alloy with 2.0% Nd addition,and the Al2Nd particle phase is almost dominant in the one with 2.5% Nd addition. Compared with those of one with 1.0% Nd addition,the elongation,tensile strength and yield strength of the one with 2.0% Nd addition are increased by 33%,14% and 4%,respectively,and those of alloy with 2.5% Nd addition are increased by 44%,18% and 6%,respectively.