固溶时效处理对ZL108铝合金组织和性能的影响

Study of Solution Aging Treatment on Microstructure and Properties of ZL108 Aluminum Alloy

采用OM、SEM和拉伸试验机研究了固溶时效处理对ZL108铝合金组织与性能的影响。结果表明:ZL108铝合金铸态组织中存在大量长棒状或块状的共晶硅相;经固溶时效处理后,粗大的共晶硅相减少,呈短棒状或者蠕虫状。铸态ZL108铝合金中呈块状分布的析出相含有较高的Si、Mn等元素;经固溶时效处理后,大部分粗大共晶硅相重溶进入基体,数量明显减少。但由于这些共晶硅相具有较好的热稳定性,在较短的固溶时间较内不能充分溶解。固溶时效处理后,粗大共晶硅相转变为稳定的细小沉淀相,分布范围更加广泛,提高了合金的抗拉强度,但沉淀相质地较脆,使得合金的塑性略有下降。

The effect of solution aging treatment on microstructure and properties of ZL108 aluminum alloy was studied by OM, SEM and tensile testing machine. The results showed that there were a large number of long rod or block eutectic silicon phases in as-cast ZL108 aluminum alloy. After solution aging treatment, the coarse eutectic silicon phase was greatly reduced and appeared as a short rod or worm. The precipitates in as-cast ZL108 aluminum alloy contained high Si, Mn and other elements and distributed in blocks. After solution aging treatment, most of the coarse eutectic silicon phase remelted into the matrix, and the number was greatly reduced. However, eutectic silicon phases had good thermal stability, they were not fully dissolved in a short solution time. After solution aging treatment, the coarse eutectic silicon phase turned into a stable fine precipitate phase, which was more widely distributed, so improved the tensile properties of the alloy, but the precipitate phase was brittle, which made the plasticity slightly reduce.