Al-Si合金在凝固过程中颗粒和枝晶组织的演变  

EVOLUTION OF GLOBULAR AND DENDRITIC STRUCTURES IN SOLIDIFICATION OF Al-Si ALLOYS

作　　者：赵建新[1] 朱鸣芳[1] 金宰民[2] 洪俊杓[2] 

机构地区：[1]东南大学材料科学与工程系,南京210096 [2]韩国延世大学冶金系,汉城120749

出　　处：《理化检验（物理分册）》2004年第9期433-438,共6页Physical Testing and Chemical Analysis(Part A:Physical Testing)

基　　金：国家自然科学基金资助项目(50371015);教育部留学回国人员科研启动基金资助项目

摘　　要：通过改变和控制浇注温度、冷却速度和半固态保温时间,研究了亚共晶Al Si合金在不同凝固条件下初生相形貌的演变。结果表明,浇注温度对初生相形貌的影响最大。当浇注温度在液相线附近,冷却速度为0.3℃/s,并在半固态状态下保温1～5min的条件下,初生相为理想的颗粒状组织。随着浇注温度和冷却速度的提高,初生相由颗粒状向枝晶组织演变。此外,添加晶粒细化剂有利于颗粒组织的形成。在试验的基础上,采用改进的CellularAutomaton(MCA)模型进行计算机数值模拟,研究了Al Si合金在凝固过程中初生相的演变机制。In this study, hypoeutectic Al-Si alloys were solidified under various conditions to investigate the evolution of the morphology of primary phase by changing and controlling pouring temperature, cooling rate, and semi-solid isothermal holding time.The results show that pouring temperature has the most important effect on the morphology of primary phase.When pouring temperature is low near to the liquids temperature with a low cooling rate of 0.3℃/s and isothermal holding for 1～5 min in semi-solid state. The morphology of primary phase is ideal globular microstructures.As the pouring temperature and the cooling rate increase, the morphology of the primary phase transfers from globular to dendritic.It was also found that inoculation favors the formation of globular structure.Based on the experiments, a Modified Cellular Automaton (MCA) model was applied to investigate the mechanism of evolution of the primary phase morphology during solidification of Al-Si alloys.

关 键 词：半固态成形 颗粒组织 枝晶组织 浇注温度 冷却速度 计算机模拟 

分 类 号：TP311.1[自动化与计算机技术—计算机软件与理论] TG140.21[自动化与计算机技术—计算机科学与技术]