定向凝固钴基合金DZ40M高温缺口疲劳性能及其断口研究  

Studies of High-Temperature Notch Fatigue Property and Fracture of a Directional Solidified Co-Base Superalloy

作　　者：姜文辉[1] 姚向东[1] 管恒荣[1] 胡壮麒[1] 

机构地区：[1]中国科学院金属研究所,沈阳110015

出　　处：《稀有金属材料与工程》1998年第6期340-343,共4页Rare Metal Materials and Engineering

摘　　要：研究了定向凝固钴基高温合金DZ40M700℃和900℃缺口疲劳性能及疲劳断口。结果表明，DZ40M合金具有较高的抗高温缺口疲劳破坏能力，700℃和900℃缺口疲劳强度分别为285MPa和203MPa，且表现出低的疲劳缺口敏感性，700℃和900℃疲劳缺口敏感度仅为0．146和0．153。在交变载荷作用下，700℃缺口疲劳裂纹是以小平面方式、沿着｛111｝滑移面扩展；而900℃缺口疲劳裂纹是在交变载荷和环境氧化综合作用下，开始沿着｛001｝解理面，随后以疲劳辉纹方式扩展。DZ40M合金的独特显微组织结构和优异的静态力学性能（特别是塑性）是其具有良好的抗高温缺口疲劳性能的主要原因。The notch fatigue behaviours of a directionally solidified Co-base superalloy at 700℃ and 900℃ in air have been investigated and the fracture surfaces have been observed using SEM. The results show that the alloy possesses a high notch fatigue resistance, and that the notch fatigue limits at 700℃ and 900℃ are 285 MPa and 203 MPa, respectively. The alloy exhibits low notch sensitivity(about 0. 15). At 700℃, a fatigue crack propagates along the {111} slip plane, while at 900℃, under the effect of a cyclic stress and environmental oxidization, the crack grows initially along the {001} cleavage plane and then propagates with a striate mode. The high notch fatigue resistance of the alloy is attributed to its peculiar microstructure and excellent static mechanical properties, especially high ductility.

关 键 词：定向凝固 钴基高温合金 缺口疲劳性能 疲劳断口 

分 类 号：TG146.16[一般工业技术—材料科学与工程] TG132.32[金属学及工艺—金属材料]