Al -18Si合金熔体的热速处理

采用熔体热速处理工艺，研究其对 Al-18Si 合金微观组织和力学性能的影响。结果发现，随过热温度升高及保温时间延长，合金初晶硅尺寸先减小后增大，合金力学性能先提高后降低。在过热温度为 930oС ，保温时间为 20 min 时，初晶硅的平均尺寸由常规熔炼工艺下的 70 μm 减小到 16 μm；拉伸强度和布氏硬度分别提高到 175. 65 MPa 和 49. 5，与常规熔炼工艺相比，分别提高 15. 38%和 8. 08%。

Thermal-Rate Treatment of Al-18Si Alloy Melt

Effects of thermal-rate treatment technique on the microstructure and mechanical properties of Al-18Si alloy were studied.The results show that the size of primary silicon tends to decrease first and then increase with the rising of superheating temperature and the prolonging of holding time,however,the change of mechanical properties of the ally sholos opposite trend.When the superheating temperature is 930 ℃ and the holding time is 20 min,the average size of primary silicon is decreased from 70 μm obtained by conventional casting technique to 16 μm;the tensile strength and the brinell hardness are increased to 175.65 MPa and 49.5,increased by 15.38% and 8.08%,respectively,compared with that obtained by the conventional casting technique.