(1. 东北大学材料与冶金学院，沈阳 110819；
2. 上海空间推进研究所，上海201112；
3. 东北大学材料各向异性与织构教育部重点实验室，沈阳 110819)
摘 要: 研究温度、保温时间及拉伸速度对半连续铸造Al-13.7Si合金高温力学性能和显微组织的影响。结果表明：半连续铸造Al-13.7Si合金在450℃拉伸时伸长率达到85.34%；Al-13.7Si合金表现出较高的高温塑性主要是由整个铝基体向细化的等轴晶转变引起的；Al-13.7Si合金适宜的热变形温度为450~500 ℃；当热变形温度高于450 ℃时，随着温度的升高或保温时间的延长，合金的伸长率和抗拉强度均呈下降趋势；随着拉伸速度的降低，各温度下合金的抗拉强度下降，而伸长率呈上升趋势。
关键字: 铝硅合金；高温力学性能；组织演变；过共晶
（1. School of Materials and Metallurgy, Northeastern University, Shenyang 110819, China;
2. Shanghai Institute of Space Propulsion, Shanghai 201112, China;
3. Key Laboratory for Anisotropy and Texture of Materials, Ministry of Education,
Northeastern University, Shenyang 110819, China）
Abstract:The high-temperature mechanical properties and microstructure of DC cast hypereutectic Al-13.7Si alloy were investigated at different temperatures, holding time and tensile velocities. The results show that the elongation of Al-13.7Si alloy is 85.43% at 450℃. Excellent ductility of the studied alloy at high temperature is due to the transformation of fine equiaxed grains in the whole Al matrix. The suitable hot deformed temperature of Al-13.7Si alloy is from 450 ℃ to 500 ℃. When the temperature of tensile is higher than 450 ℃, with increasing the temperature or prolonging the holding time, the elongation and tensile strength of the Al-13.7Si alloy decrease. With decreasing the tensile velocity, the tensile strength decreases while the elongation of the Al-13.7Si alloy increases.
Key words: Al-Si alloy; high temperature mechanical property; microstructure evolution; hypereutectic
