Al-Si-Cu三元共晶合金组织及性能影响因素研究

Influencing Factors on Microstructure and Mechanical Properties of Al-Si-Cu Ternary Eutectic Alloy

采用扫描电镜、能谱分析及力学性能表征,研究了微量合金元素、Si的变质工艺、热处理工艺对Al-Si-Cu三元共晶合金组织和力学性能的影响。结果表明,微量合金元素Ni含量在0.1%以下时,合金中的θ相为连续分布,而添加量为0.25%试样中θ相明显从连续分布变为断续分布;在Si经变质处理后,合金中的Si变为蠕球状,仍然存在的枝晶状、片状和初生Si的边缘部分也变得圆滑;固溶处理可进一步减少θ相对材料塑性的影响;当合金经过θ相的分布调整、Si变质、固溶、400℃高温等处理后,伸长率提高8.5%以上。

The effects of microalloying elements,modification process of Si and heat treatment process on the microstructure and mechanical properties of Al-Si-Cu ternary eutectic alloy were studied by SEM,EDS and mechanical properties characterization.The results show that theθphase distribution in the alloy is continuous when the Ni content is less than 0.1%,while theθphase distribution in the alloy with the Ni content of 0.25%is obviously discontinuous.After modification,the Si in the alloy becomes vermicular,and the edges of the existing dendritic,flaky and primary Si also become smooth.The effect ofθon material plasticity can be further reduced by solution treatment.Afterθphase distribution adjustment,Si modification,solid solution and 400℃high temperature treatment,the elongation of the alloy increases by more than 8.5%.