稀土元素钇及热处理对ZL101铝合金组织与力学性能的影响

The Effect of Rare Earth Element Yttrium and Heat Treatment on the Structure and Mechanical Properties of ZL101 Aluminum Alloy

摘要: 本文研究了稀土元素钇(Y)和固溶处理对Al-Si-Mg系ZL101微观组织以及力学性能的影响。结果表明，添加0.5%稀土Y可使合金内粗大的α-Al转变为均匀珊瑚状，发挥了明显的变质作用，同时可明显降低合金的抗拉强度和硬度，但对伸长率的提升并不显著。在固溶温度为525℃和时效温度为170℃时，依次对添加0.5% Y的ZL101进行1 h、2 h、3 h的固溶 + 时效处理。固溶 + 时效处理1 h时，珊瑚状α-Al变得粗大，共晶硅从过饱和固溶体中析出，ZL101的抗拉强度和伸长率明显提高。随着热处理时间的增加，共晶硅的形状逐渐粗化为长条状，拉伸断口解理断裂程度增加，力学性能逐渐下降。

Abstract: This article investigates the effects of rare earth element yttrium (Y) and solid solution treatment on the microstructure and mechanical properties of the Al-Si-Mg ZL101 system. The results show that the addition of 0.5% rare earth Y can make the coarse α-Al in the alloy into a uniform coral shape, which plays an obvious metamorphic effect, and can significantly reduce the tensile strength and hardness of the alloy, but the increase of the elongation is not significant. When the solution temperature was 525˚C and the aging temperature was 170˚C, the ZL101 with 0.5% Y was treated with solution and aging for 1 h, 2 h and 3 h successively. After solution and aging treatment for 1 h, the coral-like α-Al became coarse, the eutectic silicon was precipitated from the supersaturated solid solution, and the tensile strength and elongation of ZL101 were significantly improved. With the increase of heat treatment time, the shape of eutectic silicon gradually coarsened into long strips, the tensile cleavage fracture degree increased, and the mechanical properties gradually decreased.