熔体过热处理对过共晶Al-Si合金微观组织的影响

摘要

The effect of melt superheating treatment on microstntcture of primary silicon was studied in Al-Si alloys with 12.6 wt.%, 15 wt.%, 18 wt.% and 25wt.% silicon content. The alloys were superheated at 600-1 100 ℃ and cooled with a constant cooling rate of'3.5 K/s. We used the CAZ-2MAY metallographic analysis software to test the particle morphology, size distribution, initial volume fraction and the shape factor of crystalline silicon particles. The experimental results show that the size of primary silicon particle decreased with increasing superheating temperature. The volume fraction of primary silicon particle showed a slightly decrease with the increasing superheating temperature.%研究了熔体过热处理对于含12.6％、15％、18％和25％Si的过共晶铝硅合金组织形貌的影响.熔体过热处理温度范围600～1100℃,恒定冷却速度为3.5 K/s,利用CAZ-2MAY金相分析软件测试了初晶硅的粒子形貌、尺寸分布、初晶硅粒子的体积百分含量及形状因子.结果显示,随着熔体过热处理温度的升高,初晶硅粒子的微观组织形态发生变化,初晶硅粒子尺寸呈现持续减小的趋势,有明显的变质效果；初晶硅体积分数呈现小幅度的降低.