GH742合金中γ′相粗化动力学研究  

γ′ Particles Coarsening Kinetics in Nickel-base Superalloy GH742

作　　者：李红宇[1] 左玲立[1] 宋西平[1] 王艳丽[1] 陈国良[1] 

机构地区：[1]北京科技大学新金属材料国家重点实验室,北京100083

出　　处：《材料工程》2007年第8期8-11,共4页Journal of Materials Engineering

基　　金：国家自然科学基金资助项目(50471097)

摘　　要：采用场发射扫描电镜观察和定量金相分析等方法,研究了GH742合金在900,950,1050℃时效时,基体中γ′相的粗化规律。结果表明:合金在一定温度时效时,基体中初期析出的高密度细小γ′相随时效时间延长逐渐长大为低密度粗大γ′相,即发生Ostwald熟化;在1050℃时效2880min后γ′相形貌出现方化并沿一定方向排列;合金在时效过程中γ′相长大规律符合传统的LSW理论,并且随时效温度增高,γ′相粗化速率增加;用作图法得出了GH742合金中γ′相粗化激活能为(289.53±1.48)kJ/mol,这同Al,Ti等元素在Ni中的扩散激活能相当,说明GH742合金中γ′相的长大粗化主要由Al,Ti等元素在Ni基体中的扩散所控制。FEG-SEM observation and quantitative phase analysis technique were employed to study the coarsening behavior and coarsening kinetics of γ′ particles after 900,950,1050℃ heat treatment in superalloy GH742. The results showed that with the increase of time,the number of small sphere γ′particles decreased meanwhile the big cube γ′particles increased because of the Ostwald ripening . The coarsening behavior of γ′particles obeyed the LSW theory at different temperature and the growth rate of γ′ particles increased at elevated temperature. The activation energy of γ′ particles coarsening in GH742 is （289. 53±1.48） kJ /mol, which mean that the γ′ particles coarsening are controlled by the diffusion mechanics of the Al, Ti in the Ni matrix.

关 键 词：高温合金 γ′相 粗化动力学 激活能 

分 类 号：TG132.32[一般工业技术—材料科学与工程]