机械搅拌工艺对Al-30Si合金初生Si组织的影响

Influences of Mechanical Stirring on Microstructure of Primary Silicon in Hypereutectic Al-30Si Alloys

研究了机械搅拌工艺对Al-30Si合金初生Si组织的影响。利用光学显微镜和金相分析软件对不同机械搅拌工艺下未变质和变质Al-30Si合金组织进行观察、分析和计算。结果表明,控制搅拌温度和搅拌速度可以细化和球化初生Si颗粒,细化需要较高的搅拌速度和较低的搅拌温度,球化需要较高的搅拌速度和较高的搅拌温度。搅拌速度为900r/min、搅拌温度为680℃时未变质Al-30Si合金中初生Si颗粒细化效果最佳;搅拌速度为900r/min、搅拌温度为765℃时变质Al-30Si合金中初生Si颗粒球化效果最佳。

The influences of mechanical stirring on microstructure of primary silicon in hypereutectic Al-Si alloys were analyzed.The microstructure of modified and un-modified Al-30 Si alloys were observed by optical microscope and metallographic analysis software.The results show that the primary silicon particles can be refined and spheroidized obviously by controlling the stirring temperature and speed,where the refinement of grain is dependent on the higher speed and lower temperature,and spherodization of primary phase is controlled by the higher speed and higher temperature.With stirring at 900r/min and680 ℃,primary silicon particles exhibit the satisfied refinement in un-modified Al-Si alloy,while with at900r/min and 765 ℃,primary silicon particles have the acceptable spheroidization effects in modified Al-Si alloy.