半固态触变模锻7A04合金的力学性能  

Mechanical properties of semi-solid thixoforging 7A04 alloy parts

作　　者：田文彤[1] 

机构地区：[1]常州工学院机电工程学院,江苏常州213002

出　　处：《锻压技术》2012年第5期63-66,共4页Forging & Stamping Technology

基　　金：江苏省高校自然科学基础研究资助项目(07KJD460007)

摘　　要：采用2000kN压力机,对半固态7A04合金进行了触变模锻实验。结果表明:半固态触变模锻成形可以获得组织致密、轮廓清晰、充型完整的成形件;半固态触变模锻件的微观组织和力学性能与坯料的制备方法有关,采用SIMA法所获得的成形件的微观组织为晶粒细小、均匀的再结晶组织,因此其组织致密,在拉伸过程中部分晶粒发生塑性变形,断口中多处出现撕裂棱,其力学性能明显好于挤压态坯料;在加热温度为600℃、保温时间为10min时SIMA坯料模锻件的伸长率和抗拉强度最高,接近于热挤压态棒料的力学性能,优于同等条件下挤压态合金的半固态模锻成形件,其抗拉强度和伸长率分别提高11.8%和78.5%。Thixoforging tests were conducted on a 2000 kN press to form semi-solid 7A04 alloy parts.The results show that integrally formed part with compact structure and clear shape is obtained by thixoforging process.The microstructure and mechanical properties of thixoforging parts are related to their billets making method.The microstructure of such parts made by SIMA method is mainly the fine and uniform recrystallization texture.In addition,plastic deformation was found locally during the elongated process and tearing ridges were found at fracture surfaces,which make the mechanical properties of thixoforging parts superior to that of extruded billet.The elongation rate and strength of thixoforging parts came to the highest value when the SIMA billet was reheated to 600 ℃ for 10 min,which is similar to that of hot extruding billet.Compared to the extruded state,the strength and elongation rate made by SIMA method were increased to 11.8% and 78.5%,respectively.

关 键 词：半固态 触变模锻 7A04合金 力学性能 

分 类 号：TG249.9[金属学及工艺—铸造]