喷射成形7075铝合金欠时效回归再时效热处理
Retrogression and Reaging Treatment of Underaged Spray Forming 7075 Aluminum Alloy
曲迎东 1苏睿明 1唐才宇 2李荣德 1解骐鸣 1尤俊华1
作者信息
- 1. 沈阳工业大学材料科学与工程学院
- 2. 沈阳鼓风机集团股份有限公司
- 折叠
摘要
采用透射电镜、拉伸测试等方法,研究欠时效回归再时效处理对喷射成形7075铝合金显微组织和力学性能的影响,并与单级峰值时效和常规回归再时效处理相比较.结果表明,采用120℃×12 h欠时效预处理比120℃×24 h峰值时效预处理更有利于在回归处理后合金晶内析出相的回溶,回归处理过程可使合金晶界析出相充分断开,再时效后晶内的析出相细小弥散,合金抗拉强度和屈服强度分别为776和723 MPa,均高于T6峰值时效和常规回归再时效水平.
Abstract
Effects of retrogression and reaging (RRA) treatment on microstructure and mechanical properties of underaged spray forming 7075 aluminum alloy were investigated by transmission electron microscope (TEM) and tensile testing,and compared with those of alloys under peak aging and conventional RRA treatment.The results show that underaging at 120 ℃ for 12 h as preaging treatment is more beneficial for the re-dissolution of precipitates in matrix than peak aging (T6,120 ℃ × 24 h) in retrogression treatment.By retrogression treatment,the precipitates on the grain boundary are disconnected completely.After reaging treatment,fine and dispersed precipitates can be observed in the grain.And the tensile strength and yield strength of the alloy reach 776 MPa and 723 MPa,respectively,which are higher than those in T6 or conventional RRA treatment.
关键词
喷射成形/7075铝合金/欠时效/回归再时效/显微组织Key words
Spray Forming/7075 Aluminum Alloy/Underage/Retrogression and Reaging/Microstructure引用本文复制引用
基金项目
辽宁省高等学校优秀人才计划资助项目(LR2011003)
沈阳市工业科技攻关资助项目(F11-033-2-00)
辽宁省创新团队资助项目(LT2002004)
出版年
2014
NETL
NSTL
维普
万方数据