Formation of Fine Spheroidal Microstructure of Semi-Solid Al—Zn—Mg—Cu Alloy by Hyperthermally and Subsequent Isothermally Reheating  

作　　者：Gang Chen Jufu Jiang Zhiming Du Qi Cao Hongwei Li Xin Zhang 

机构地区：[1]School of Materials Science and Engineering,Harbin Institute of Technology [2]Technology Institute,Beijing North Vehicle Group Corporation [3]Beijing Engineering Research Center for Advanced Manufacturing and Elevation of Special Vehicle Parts

出　　处：《Journal of Materials Science & Technology》2013年第10期979-982,共4页材料科学技术（英文版）

基　　金：the National Natural Science Foundation of China under Grant Nos.50774026,50875059 and 51174064

摘　　要：The high strength 7xxx series aluminium alloys are usually difficult to be prepared as semi-solid feedstock, because some dispersoid particles （soluble only in liquid） could pin at grain and subgrain boundary to make the alloy difficultly recrystallise. In this work, a novel multistep reheating regime is developed for recrystallisation and partial melting （RAP） route to prepare fine spheroidal microstructure of semi-solid AI-Zn- Mg-Cu alloy. After reheating to 665 ℃, holding for 4 min and subsequent isothermally holding at 620 ℃ with total heating time of 15 min, fine spheroidal microstructures with grain size of-40 μm were prepared without remained unrecrystallised grains and directionality, which are much finer than the conventionally obtained microstructures （-100 μm）.The high strength 7xxx series aluminium alloys are usually difficult to be prepared as semi-solid feedstock, because some dispersoid particles （soluble only in liquid） could pin at grain and subgrain boundary to make the alloy difficultly recrystallise. In this work, a novel multistep reheating regime is developed for recrystallisation and partial melting （RAP） route to prepare fine spheroidal microstructure of semi-solid AI-Zn- Mg-Cu alloy. After reheating to 665 ℃, holding for 4 min and subsequent isothermally holding at 620 ℃ with total heating time of 15 min, fine spheroidal microstructures with grain size of-40 μm were prepared without remained unrecrystallised grains and directionality, which are much finer than the conventionally obtained microstructures （-100 μm）.

关 键 词：Al-Zn--Mg--Cu alloys MICROSTRUCTURE SEMISOLID Recrystallization 

分 类 号：TG146.21[一般工业技术—材料科学与工程]