时效热处理对新型Co-Ni基高温合金组织和性能的影响

Effect of Aging Treatment on Microstructure and Properties of Novel Co-Ni Based Superalloy

使用不同的热处理工艺对新型Co-Ni基高温合金进行时效处理,通过扫描电子显微镜和维氏硬度仪分析了时效热处理工艺对合金显微组织及性能的影响。结果表明,经时效热处理后,新型Co-Ni基高温合金组织内部析出了近似球状的γ'相,并且γ'相的体积分数达到50%以上。析出的γ'相的粒径尺寸随着时效温度和时效时间的增加而增大,而γ'相的体积分数主要由时效温度决定,与时效时间无关,且随着时效温度的升高而减少;根据弱对偶耦合和强对偶耦合模型,计算得出最佳的γ'相粒径尺寸在35~40 nm。

A new type of Co-Ni based superalloy was aged by different heat treatment processes.The effects of aging treatment on the microstructure and properties of the alloy were analyzed by scanning electron microscope(SEM)and Vickers hardness tester.The results show that spherical γ' phase precipitates in the microstructure of the new Co-Ni based superalloy after aging treatment,and the volume fraction of γ' phase reaches more than 50%.The grain size of the precipitated γ' phase increases with the increasing of aging temperature and time,while the volume fraction of γ' phase is mainly determined by aging temperature,and has nothing to do with aging time,and decreases with the increasing of aging temperature.According to the weak and strong dual coupling models,the optimal particle size of γ' phase is calculated to be between 35 and 40 nm.