Thermomechanical Fatigue Behavior of Powder Metallurgical Nickel Based Superalloy FGH96  

作　　者：GU Yu-li TAO Chun-hu HE Yu-huai 

机构地区：[1]Beijing Institute of Aeronautical Materials, Beijing 100095, China

出　　处：《Journal of Iron and Steel Research International》2010年第6期74-79,共6页

基　　金：Item Sponsored by National Science and Technology Pillar Programin the 11th Five-Year Plan of China (2006225)

摘　　要：The fracture behavior of the thermomechanical fatigue （TMF） of the powder metallurgical nickel based superalloy FGH96 was investigated under in-phase （IP） and out-of-phase （OP） loadings in the temperature range from 550 ℃ to 720 ℃ and the mechanical strain amplitude range from 0.3% to 0.8%. The results show that the FGH96 TMF fracture character is intergranular for the IP samples and transgranular cleavage-like for the OP samples, at the same strain amplitude, the fatigue life is shorter for the IP than that for the OP samples that is related to crack propagation along grain boundary on the IP samples, the γ′ size is larger in the IP than that in the OP sample, which is related to the bulk diffusion processes accelerated by the tensile strain during the high temperature portion of the IP cycle. Dislocation pairs and stacking faults are main microstructures induced by IP TMF, and they are hindered by the grain boundary, which likely resulted in the crack propagation along the grain boundary in the IP samples.The fracture behavior of the thermomechanical fatigue （TMF） of the powder metallurgical nickel based superalloy FGH96 was investigated under in-phase （IP） and out-of-phase （OP） loadings in the temperature range from 550 ℃ to 720 ℃ and the mechanical strain amplitude range from 0.3% to 0.8%. The results show that the FGH96 TMF fracture character is intergranular for the IP samples and transgranular cleavage-like for the OP samples, at the same strain amplitude, the fatigue life is shorter for the IP than that for the OP samples that is related to crack propagation along grain boundary on the IP samples, the γ′ size is larger in the IP than that in the OP sample, which is related to the bulk diffusion processes accelerated by the tensile strain during the high temperature portion of the IP cycle. Dislocation pairs and stacking faults are main microstructures induced by IP TMF, and they are hindered by the grain boundary, which likely resulted in the crack propagation along the grain boundary in the IP samples.

关 键 词：nickel based superalloy powder metallurgy thermomechanical fatigue γ′ size DISLOCATION 

分 类 号：TG146.15[一般工业技术—材料科学与工程] V261.3[金属学及工艺—金属材料]