等温处理对Al-7Si-4Cu合金组织和硬度的影响  

Effects of Isothermal Heat Treatment on Microstructure and Ambient Hardness of Al-7Si-4Cu Alloy

作　　者：戴世娟[1] 陈刚[1] 

机构地区：[1]江苏大学材料科学与工程学院

出　　处：《特种铸造及有色合金》2007年第3期224-226,共3页Special Casting & Nonferrous Alloys

基　　金：江苏省高新技术研究项目(BG2005026)

摘　　要：研究了铸造Al-7Si-4Cu合金在半固态等温处理过程中组织、性能的变化。结果表明,通过调整等温处理时间、温度不仅可以改善铸造铝硅铜合金的组织,而且提高了合金的力学性能。在一定的冷却速率下,适当延长等温处理时间、提高等温处理温度有利于硅相的圆整化、细化。在半固态温度下进行保温,当保温时间为5min时,可获得弥散相,保温温度高,弥散相多;延长保温时间至10min,未发现弥散相析出,而硅相圆整、细小,分布均匀,弥散相多,合金硬度就高。Effects of isothermal heat treatment on microstructure and properties of cast Al-7Si-4Cu alloy have been investigated.It is revealed that isothermal heat treatment,including adjusting time and temperature,can not only refine the microstructure of the alloy,but also improve the mechanical properties of the cast Al-7Si-4Cu alloy.The Si phase in microstructure of the alloy can be spheroidized and refined with extending isothermal time and increasing isothermal temperature in the condition of a given cooling rate.The disperoids in the microstructure can be observed at semi-solid temperature with holding time for 5 min,which becomes more and more with increasing in holding temperature,however,the disperoids would be disappeared with holding time for 10 min.The micro-hardness of the alloy can be improved with increasing in spheroidization and fine and uniform distribution of Si phase.

关 键 词：等温处理 铝硅铜合金 硬度 合金组织 

分 类 号：TG249.9[金属学及工艺—铸造]