挤压态7075铝合金半固态加热过程中的组织演变  

Semi-solid Microstructure Evolution of As-extruded 7075 Aluminum Alloy during Semi-solid Reheating Process

作　　者：张靖宇[1] 刘洪军[1] 

机构地区：[1]兰州理工大学省部共建有色金属先进加工与再利用国家重点实验室

出　　处：《特种铸造及有色合金》2016年第7期717-721,共5页Special Casting & Nonferrous Alloys

基　　金：甘肃省自然科学基金资助项目(145RJZA082)

摘　　要：研究了加热温度和保温时间对部分重熔再结晶方法(RAP)制备7075铝合金半固态坯料过程中的组织演变的影响。结果表明,通过在半固态温度区间加热可以将挤压态7075铝合金的纤维组织转变为半固态颗粒状晶粒组织。随着加热温度的提高和保温时间延长,挤压态组织逐渐消失,颗粒状晶粒经再结晶生长并合并长大;颗粒状晶粒的尺寸随加热温度和保温时间的增加而变大。在试验条件下,高温短时间加热比低温长时间下获得的半固态组织更加细小均匀。通过试验得出RAP法制备7075铝合金半固态坯料的优化工艺参数为600℃下保温5min。Semi-solid 7075 aluminum alloy billets were prepared by recrystallization and partial remeltmg （RAP） technology. The influences of heating temperature and holding time on microstructure evolution were investigated. The results show that the fibrous microstructure in as-extruded 7075 aluminum alloy is transformed into semi-solid granular ones after heating treatment. As increasing in the heating tem- perature and holding time, the as-extruded microstructure gradually disappears, and the granular grains are generated and grown through recrystallization process. The size of semi-solid granular microstruc- ture is increased with the increase of heating temperature and holding time. Under the experimental conditions, the semi-solid microstructure heated at a higher temperature with short time is the more homo- geneous than that of ones heated at a lower temperature with long time. Based on experimental analysis, the satisfied semi-solid 7075 aluminum alloy billets by RAP method can be fabricated with heating at 600 ℃ for 5 min.

关 键 词：7075铝合金 半固态 RAP法 组织演变 

分 类 号：TG249.2[金属学及工艺—铸造]