钛、硼细化处理AZ91D半固态保温过程中组织演变  

Microstructural Evolution of AZ91D Refined with Ti-B during Semisolid Holding

作　　者：王瑞权[1] 冯旭东[2] 郭世敬[2] 贺睿[2] 曹晶晶[2] 王强[2] 

机构地区：[1]兰州理工大学甘肃省有色金属新材料省部共建国家重点实验室,甘肃兰州730050 [2]河南理工大学材料科学与工程学院,河南焦作454003

出　　处：《有色金属加工》2009年第3期9-11,19,共4页Nonferrous Metals Processing

摘　　要：研究了用钛、硼细化剂细化处理AZ91D镁合金的铸态组织和其在半固态重熔加热过程中的组织变化。结果表明,该合金的微观组织在此过程中经历了四个阶段:初期的快速粗化阶段、组织分离阶段、晶粒球状化阶段和最后的粗化阶段。在升温过程中,晶界处的共晶组织(α+β)中的β相先发生溶解,之后随着温度进一步升高,α相又发生熔化分离,并在等温处理过程中逐渐变为球状。当等温时间过长时,球状颗粒有长大的趋势。The as-cast structure of Mg-alloy AZ91D treated with refiner Ti-B and the structural evolution during semisolid reheating was investigated. The results indicated that during this process, its microstructure experienced four stages： initial coarsening stage, structure separation stage, grain spheroidizing stage and the final coarsening stage. During the temperature increasing, the βphase at grain interface of eutectic structures （α＋β） is dissolved firstly and then with the increasing of temperature α phase is melted and separated. The primary structure of AZ91D alloy takes the form of spherical structure gradually. If the isothermal time duration is excessive, the spherical structure will grow up.

关 键 词：AZ91D合金 细化剂 半固态 球状晶粒 

分 类 号：TG146.2[一般工业技术—材料科学与工程]