Microstructure evolution of semi-solid 2024 alloy during two-step reheating process  

作　　者：王顺成 李元元 陈维平 郑小平 

机构地区：[1]School of Mechanical Engineering and Automotive,South China University of Technology,Guangzhou 510640, China

出　　处：《中国有色金属学会会刊：英文版》2008年第4期784-788,共5页Transactions of Nonferrous Metals Society of China

基　　金：Project(20060400749) supported by the Postdoctoral Science Foundation of China;Project supported by the Postdoctoral Novel Science Foundation of South China University of Technology,China

摘　　要：A two-step reheating process was proposed and applied to perform reheating experiments on the semi-solid 2024 alloy billet. In this process, the semi-solid billet was firstly heated over liquidus temperature and then isothermally held at solid-liquid zone temperature. Microstructure evolution of the semi-solid billet during two-step reheating was studied by optical microscope and compared with that during isothermal reheating. The results show that the remelting rate of the semi-solid billet during two-step reheating is faster than that during isothermal reheating. Under the same reheating time, the grains of the semi-solid billet reheated by two-step reheating process are finer and rounder than those by isothermal reheating process. The present experimental results indicate that accelerating the formation of liquid phase during the two-step reheating process can restrain the coalescence of grains to a certain extent, and thus refine the grain size and promote the grain spheroidization.A two-step reheating process was proposed and applied to perform reheating experiments on the semi-solid 2024 alloy billet. In this process, the semi-solid billet was firstly heated over liquidus temperature and then isothermally held at solid-liquid zone temperature. Microstructure evolution of the semi-solid billet during two-step reheating was studied by optical microscope and compared with that during isothermal reheating. The results show that the remelting rate of the semi-solid billet during two-step reheating is faster than that during isothermal reheating. Under the same reheating time, the grains of the semi-solid billet reheated by two-step reheating process are finer and rounder than those by isothermal reheating process. The present experimental results indicate that accelerating the formation of liquid phase during the two-step reheating process can restrain the coalescence of grains to a certain extent, and thus refine the grain size and promote the grain spheroidization.

关 键 词：半固态金属 2024合金 微观结构 两步加热过程 

分 类 号：TG115[金属学及工艺—物理冶金]