【摘要】 为了提高铸造Al-7Si-0.3Mg-0.3Y合金的力学性能，对其进行热处理，然后通过扫描电镜、维氏硬度仪等设备研究最佳热处理工艺，并分析铸态、T5态、T6态合金的力学性能。结果表明，最佳固溶工艺为530℃×6 h，此时共晶Si尺寸最小且形貌较为圆润，固溶时间超过6 h时，共晶Si开始粗化；与铸态相比，T5态合金的抗拉强度提高了26.7%，伸长率提高了28.5%；最佳时效工艺为160℃×11.5 h，此时合金硬度达到峰值，与铸态合金相比抗拉强度提高了31.1%，伸长率提高了49.7%。因此，合金最佳热处理工艺为530℃×6 h+160℃×11.5 h。更多还原

【Abstract】 Heat treatment was carried out to improve the mechanical properties of cast Al-7Si-0.3Mg-0.3Y alloy. The optimal heat treatment process was explored by scanning electron microscope, Vickers hardness tester and other equipments, and the mechanical properties of alloys in as-cast, T5 and T6 states were analyzed. The results indicate that the optimal solid solution process is 530 ℃ × 6 h, where the size of eutectic Si reaches the minimun value with relatively round morphology. When the solid solution time exceeds 6 h, the eutectic Si is coarsened. The tensile strength and elongation of the alloy are increased by 26.7% and 28.5%, respectively, compared with that of ones in as-cast state. The optimum aging process is 160 ℃ × 11.5 h, where hardness of the alloy reaches the peak value, and the tensile strength and elongation are increased by 31.1% and 49.7%, respectively. Therefore, the heat treatment process of the alloy is 530 ℃ × 6 h solid solution + 160 ℃ × 11.5 h aging.更多还原