摘要
对FGH97粉末高温合金盘件进行热处理,采用光学显微镜、扫描电子显微镜、能谱仪和蠕变试验机研究了不同固溶冷速下合金的显微组织、蠕变性能和蠕变机制。研究表明:随固溶冷速的增加,γ′相尺寸减小,富Ti、Nb、Hf的MC型碳化物由连续析出变为颗粒状弥散析出。在750℃/450 MPa蠕变试验条件下,固溶冷速为94℃/min的样品性能明显优于43℃/min。FGH97粉末高温合金在750℃/450MPa条件下的蠕变机制为位错切割γ′相,在晶界处产生应力集中导致裂纹的萌生,裂纹沿着晶界碳化物扩展,最终导致材料的断裂。弥散颗粒状分布的碳化物能有效抑制微裂纹的贯通。
FGH97 nickel-base superalloy was processed at different solution cooling rates.Then the microstructure and creep behavior of the superalloy were studied by optical microscope,scanning electron microscope,energy disperse spectroscopy and creep testing machine.The results show that the size ofγ′precipitates decreases and the carbide precipitation changes from continuous to discrete with the increase of the solution cooling rate,and GB carbides are rich in Ti,Nb,and Hf.The creep performance of the alloy with a solution cooling rate of 94℃/min is significantly better than that with a cooling rate of 43℃/min under 750℃/450 MPa.γ′cutting is the deformation mechanism of FGH97 alloy under 750℃/450 MPa,stress concentration at grain boundary leads to initial cracks,which then propagate along grain boundary and finally lead to fracture.The disperse-distribution carbides on grain boundary can inhibit the propagation of microcracks.
作者
张海
邹志欢
龙安平
王冲
欧业韬
Zhang Hai;Zou Zhihuan;Long Anping;Wang Chong;Ou Yetao(Shenzhen Wedge Central South Research Institute Co.,Ltd,Shenzhen 518045,China)
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2020年第7期2488-2493,共6页
Rare Metal Materials and Engineering
基金
广东省重点领域研发计划项目(2019B010935001)
深圳市海外高层次人才资金(20150128085205453)。
关键词
粉末高温合金
微观组织
蠕变
断裂
晶界碳化物
powder metallurgy superalloys
microstructure
creep
fracture
GB carbides
