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研究了凝固条件和热处理及微量锶对Ａ３５６合金组织与性能的影响。试验结果表明，锶的加入不仅对显微组织而且对合金中αＡｌ固溶体的弥散析出行为也有较大的改变，加入锶后的合金在冷却过程中（“隐形热处理”）的一次弥散相和随后热处理的二次弥散相都要比Ａ３５６合金细得多。这种细化作用较普通光学显微组织对力学性能的影响还要大。即使通过长时间的热处理，锶和冷却速度对显微组织的影响仍没有实质的变化。同时比较了定向凝固的Ａ３５６合金在铸态与热处理态下的质量指数，结果显示其明显高于普通条件下的Ａ３５６合金的质量指数。
The effects of solidification conditions, heat treatment and strontium on the microstructure and properties of A356 alloy were investigated. The experimental results show that the addition of strontium not only affects the microstructure but also the dispersion and precipitation behavior of the αAl solid solution in the alloy. The addition of strontium to the alloy after cooling (“invisible heat treatment”) and subsequent heat treatment The secondary dispersion are much smaller than the A356 alloy. This refinement than ordinary optical microstructure on the mechanical properties even greater impact. The effect of strontium and cooling rate on the microstructure is not substantially changed even after prolonged heat treatment. The quality index of as-cast A356 alloy in as-cast and heat-treated state was also compared. The results show that it is obviously higher than the quality index of A356 alloy under normal conditions.