Co对Al-20Si-2Cu-1Ni-0.5Mn合金微观组织和力学性能的影响

采用扫描电镜(SEM)、图像定量分析软件等,研究了在Al-20Si-2Cu-1Ni-0.5Mn合金中分别添加质量分数为0.5%、0.9%、1.5%的Co对合金微观组织和力学性能的影响。结果表明,随着Co含量的增加,合金中的含Co金属间化合物的体积分数和平均直径均有所增加,其形态也由小团块状转变为发达的树枝晶。合金的力学性能随Co含量的增加逐渐降低。Co元素对于初生Si没有明显的变质作用。

Effects of Co on Microstructure and Mechanical Properties of Al-20Si-2Cu-1Ni-0.5Mn Alloy

With the help of scanning electron microscopy(SEM) and quantitative photograph analysis software,the effects of Co content varied from 0 to 1.5% on microstructure and mechanical properties of Al-20Si-2Cu-1Ni-0.5Mn alloy were investigated.The results show that,the volume fraction and average diameter of Co-containing intermetallic compounds are increased with the increase of Co content.Meanwhile,the morphology of Co-containing phases is converted from small bulky structure to well-developed dendrites.The addition of Co has a worse effect on the tensile strength of the hypereutectic Al-Si alloy.In addition,the modification effects of Co content on primary Si in the alloy can be ignored.