Al-Cu-Mg合金粉末在半固态的组织演变及晶粒粗化机制  

Microstructure Evolution and Grain Coarsening Mechanism of Al-Cu-Mg Alloy Powder in Semi-solid State

作　　者：吴敏 刘健 罗霞 刘允中[3] 蔡仁烨 徐伟 陈晓 WU Min;LIU Jian;LUO Xia;LIU Yunzhong;CAI Renye;XU Wei;CHEN Xiao(School of Automobile and Transportation Engineering,Guangdong Polytechnic Normal University,Guangzhou 510665,China;School of New Energy and Materials,Southwest Petroleum University,Chengdu 610500,China;National Engineering Research Center of Near-net-shape Forming for Metallic Materials,South China University of Technology,Guangzhou 510640,China)

机构地区：[1]广东技术师范大学汽车与交通工程学院,广州510665 [2]西南石油大学新能源与材料学院,成都610500 [3]华南理工大学机械与汽车工程学院,广州510640

出　　处：《材料导报》2022年第24期175-181,共7页Materials Reports

基　　金：广州市科技计划项目(202102080110);国家金属材料近净成形工程技术研究中心重点实验室开放基金(2018006);四川省科技计划(2020YFH0151);国家自然科学基金(51704255)。

摘　　要：将Al-Cu-Mg合金粉末及其粉末烧结体分别加热到833 K、843 K、853 K、863 K、873 K、883 K和893 K,并保温60 min、50 min、40 min、30 min、20 min、10 min和0 min后水冷得到其半固态微观组织。通过计算半固态粉末及其烧结体的晶粒尺寸、形状因子和晶粒粗化速率,分析其组织演变规律,同时对比分析了相同成分下粉末与致密材料在半固态下的晶粒粗化机理。结果表明:随着半固态温度的提高和保温时间的延长,粉末的晶粒尺寸增加;为避免获得粗大晶粒,Al-Cu-Mg合金半固态粉末成形的参考温度应低于883 K,保温时间应在40 min以内;随着温度的提高,粉末的晶粒粗化速率增大,在883 K时达到19μm^(3)/s,但远远小于同成分下致密材料的粗化速率,这是半固态粉末成形技术能够获得细小组织的一个重要原因。The Al-Cu-Mg alloy powder and its sintered body were heated to 833 K,843 K,853 K,863 K,873 K,883 K and893 K,respectively,and then were water-cooled to obtain their semi-solid microstructures after being held for 60 min,50 min,40 min,30 min,20 min,10 min and0 min,respectively. By calculating the grain size,shape factor and grain coarsening rate of thesemi-solid powder and its sintered body,thegrain coarsening mechanism of the powder and the dense material(with the same composition)at semi-solid state was compared and analyzed. The results show that with the increase of the semi-solid temperature and the holding time,the grain size of the powder increases. The temperature of Al-Cu-Mg alloy during semi-solid powder forming is recommended less than 883 K,and the holding time is supposed to be within40 min. As the temperature increases,the coarsening rate of powder at a semisolid state increases,and the coarsening rate reaches19 μm^(3)/s at883 K,which is much less than that of the dense material with the same composition,however. This is an important reason why the semi-solid powder forming technology can obtain fine microstructure.

关 键 词：AL-CU-MG合金 半固态粉末 组织演变 晶粒长大 粗化速率 

分 类 号：TG306[金属学及工艺—金属压力加工]