(1. 河北科技大學(xué) 材料科學(xué)與工程學(xué)院，石家莊 050018；
2. 北京交通大學(xué) 機(jī)械與電子控制工程學(xué)院，北京 100044)
摘 要: 采用電磁攪拌法制備具有不同微觀初始組織特征的半固態(tài)合金熔體，利用半固態(tài)擠壓鑄造法鑄造螺旋線試樣，使用定量金相技術(shù)分析試樣的初始組織、成形的螺旋線試樣不同長度上的初生相微觀組織特征參數(shù)(固相率、晶粒尺寸和形狀因子)，研究半固態(tài)合金熔體充型過程中初生相組織的演變規(guī)律。結(jié)果表明：初生固相率在充型的沿程流動過程中變化較小；初生相的晶粒尺寸、形狀因子沿充型長度呈現(xiàn)波浪形變化，波峰和波谷出現(xiàn)的位置與充型長度沒有明確的關(guān)系；充型后初生相晶粒尺寸的變化幅度與充型前半固態(tài)合金熔體初生相晶粒尺寸的大小有對應(yīng)關(guān)系。
關(guān)鍵字: 初始組織；組織演變；半固態(tài)；充型過程
primary phase in mold filling
（1.School of Material Science and Engineering, Hebei University of Science and Technology,
Shijiazhuang 050018, China;
2. School of Mechanical and Electronic Control Engineering, Beijing Jiaotong University, Beijing 100044, China）
Abstract:Semi-solid alloy melt with different initial structure prepared by electromagnetic stirring method was poured into a special mold and a series of the spiral samples were obtained by semi-solid squeeze casting process. The characteristic parameters of the primary structure such as solid phase rate, grain size and shape factor of the spiral samples located at different filling length were investigated by the quantitative metallographic techniques to explore the evolution of primary phase of the semi-solid alloy melt during the mold filling. The results show that the variance of solid phase rate of primary phase is small along the path of mold filling. The grain size and shape factor vary in a wave-shape along the filling length. The positions of peak and trough of the wave have no clear relationship with the filling length. The range of variation of grain size after filling has a coincidence relation with that of primary phase before filling.
Key words: initial structure; microstructure evolution; semi-solid; filling process
