摘要
喷射沉积材料具有细小的等轴晶组织,是优良的半固态加工(Semisolid metalprocessing,SSM)的坯料。喷射沉积材料在半固态加工过程中主要的组织转变是晶粒长大,如何控制其晶粒长大速度是喷射沉积材料半固态加工的关键问题。通过对喷射沉积A356铝合金在不同温度下保温不同的时间后进行组织观察,探索半固态加工工艺对组织和性能的影响规律。结果表明:半固态成形温度提高,固相分数降低,晶粒长大速度提高,在接近液相线温度约600℃时,组织出现异常长大的趋势,因此加热温度是控制半固态加工的关键因素;在低于550℃的半固态温度范围内加热时,保温时间的增加对晶粒长大的影响将减缓。
The spray deposition was suitable billet for semisolid metal processing （SSM） with finer equiaxed structure. The main microstructure change was grain growing in the SSM process, and the growing rate controlling was the key factor. The effect of SSM technology on microstructure was investigated by microstructure analysis of spray-deposited A356 alloy annealed at different temperatures for various times. The results showed that the solid phase fraction decreased and the growing rate of grain size increased with the increasing of temperature, the abnormal grain growth occurred at about 600℃ near the liquidus of A356 alloy. Therefore, the heating temperature was the key factor in the SSM processing. The grain growing rate decreased below the semisolid temperature of 550 ℃ with increasing time.
出处
《上海金属》
CAS
2009年第5期19-23,共5页
Shanghai Metals
关键词
A356铝合金
喷射沉积
半固态加工
显微组织分析
A356 Aluminum Alloy, Spraying Deposition, Semisolid Metal Processing （SSM）, Microstructure Analysis
