Ti添加量对Al-12Si-4Cu-0.5Mg合金组织与强度性能的影响

Effect of Ti adding Content on Microstructure and Strength Property of Al-12Si-4Cu-0.5Mg alloy

通过向Al-12Si-4Cu-0.5Mg合金中添加不同含量的Ti元素进行细化处理。结果表明：Ti加入量在0.15%～0.78%区间范围内,当Ti添加量在0.45%左右时合金铸态下的强度性能最好,其σb和σ0.2分别为278和116 MPa;该合金在固溶时效处理后,其σb和σ0.2可达438和122 MPa,分别较铸态提高了57.6%和5.2%。Ti元素的加入,使合金的典型共晶组织弱化,而分别向α-Al基体和Si相分化。固溶时效处理后,以Si相为主的强化相边缘明显趋于圆化,主要以短棒状及颗粒状形态存在,并弥散分布在Al基体上。

The refinment of A1-12Si-4Cu-0.5Mg alloy was proceeded by additive element Ti with different dosages from 0.15% to 0.78%. The results indicate that strength performance is best when Ti adding content is about 0.45% in AI-12Si-4Cu-0.5Mg cast alloy, while бb and б0.2 are respectively 278 MPa and 116 MPa. In addition, after solution and aging treatment of the alloy, the strength can reach 438 MPa and 122 MPa , which are 57.6% and 5.2% higher than that of AI-12Si-4Cu-0.5Mg cast alloy, respectively. Owing to the addition of Ti, the typical eutectic microstructure of the alloy are weakened and α-A1 and Si phases differentiation form. After solution and aging treatment, the margin of Si phase-based strengthening phase tends to be circular change and mainly exists in the rod like and granular morphology, as well as dispersing in A1 matrix.