热处理对无凝固收缩铝硅合金组织和性能的影响

The effect of heat treatment on the structure and the mechanical property of the aluminum-silicon alloy without solidification shrinkage

为了寻找一种无凝固收缩铝硅合金的最佳热处理工艺,主要研究了热处理对无凝固收缩铝硅合金组织和力学性能的影响规律.结果发现:无凝固收缩铝硅合金的组织主要受固溶温度的影响,随固溶温度的提高,合金中化合物相减少、共晶硅和初生硅球化;无凝固收缩铝硅合金的硬度随固溶温度和时效温度的升高及时效时间的延长均具有先增大后减小的规律,固溶温度为803～813 K、时效温度为463 K、时效时间为10 h时合金的硬度提高最大;T6处理后无凝固收缩铝硅合金的抗拉强度达到了279～302 MPa,比国际上的类似成分合金KS270、KS271和KS272合金高了40%左右.

The effects of heat treatment on the structure and mechanical property of the aluminum-silicon alloy without solidification shrinkage have been studied with the purpose of obtaining the best parameters of heat treatment. The following results have been found：The structure of the alloy mainly depends on the solid solution temperature; Increasing the solid solution temperature makes the size and amount of the compound phase reduce and the eutectic silicon and the primary silicon nodulize. The hardness of the alloy increases at the begining and then decreases with increasing the solid solution temperature, the ageing temperature and the ageing time. The hardness reaches its maximum value when the solid solution temperature is 803 -813 K, the ageing temperature is 463 K and the ageing time is 10 hours. After T6 treatment, the tensile strength of the aluminum-silicon alloy without solidification shrinkage is as high as 279-302 MPa, which is 40 % higher than the similar alloy KS270, KS271 and KS272.