摘要
利用理论计算与实际观测等手段,研究了采用近液相线方法铸造的ZL201合金坯料在进行二次加热时,α晶粒形貌演变和长大的规律.结果表明,半固态二次加热时,α晶粒形态的整个演变过程可以分为三个阶段:第一阶段为共晶组织的熔化阶段;第二阶段为α晶粒的球化阶段;第三阶段为理论液固成分的平衡阶段.在第一、二阶段α晶粒以合并方式长大;第三阶段α晶粒按Ostwald模型长大.二次加热温度影响组织演化进程,而保温时间决定α晶粒球化效果.在较高的温度下进行二次加热,能够在较短的保温时间内得到适合于触变成形的均匀细小的近球形组织.
The semi-solid ZL201 alloys cast with near-liquidus casting technology were reheated, and its microstructural evolution and α-grain growth mechanism were studied by means of theoretical calculation and actual observation. The results indicated that the mierostructural evolution of the α-grain formation consists of three stages, i.e., euteetic structure melting, grain spheroidizing and theoretical liquid-solid equilibrium. The α-grains grow in form of coalescence in the first two stages in accordance to Ostwald model in the third stage. In addition, the mierostructure evolves faster with increasing reheating temperature, and the spheroidization of α-grain depends on the isothermal holding time. It implies that the homogeneous, fine and near-spherical mierostructure can be obtained via thixoforming at relatively higher reheating temperature within shorter holding time.
出处
《东北大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2006年第6期669-672,共4页
Journal of Northeastern University(Natural Science)
基金
国家自然科学基金资助项目(50374031)
作者简介
路贵民（1965-）,男,黑龙江绥化人,东北大学教授,博士生导师;Correspondent： LU Gui-min, professor, E-mail： lu_guimin @ yahoo.com. cn
崔建忠（1950-）,男,黑龙江双城人,东北大学教授,博士生导师.
