摘要
对定向凝固 DZ4 合金 760℃和 800℃下的低周疲劳行为进行了研究,并结合断口观察,对其疲劳裂纹的萌生与扩展进行了分析。结果表明,DZ4 合金 760℃和 800℃下的低周疲劳属应力疲劳,其损伤以弹性损伤为主,弹性损伤与疲劳寿命具有很好的相关性。定向凝固 DZ4 合金高寿命低周疲劳裂纹易于萌生于试样内部或亚表面的柱状晶界。其疲劳裂纹的稳定扩展也较难形成典型的疲劳条带。
The low cycle fatigue (LCF) and fracture behaviors of directionally solidified DZ4 superalloy at 760degreesC and 800degreesC were studied. Combined with fracture observation, the fatigue crack initiation and propagation were analyzed. The results show that the LCF of DZ4 superalloy at 760degreesC and 800degreesC can be contributed to stress fatigue owing to the main elastic damage in LCF processing. The elastic damage has a favorite relativity to the fatigue life. The high life LCF cracks of DZ4 super alloy favorably initiate at the transverse segment of longitudinal grain boundary. And formation of typical fatigue striation on fatigue crack steady propagation is difficult.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2005年第2期217-220,共4页
Rare Metal Materials and Engineering
关键词
定向凝固合金
低周疲劳
弹性损伤
directionally solidified super alloy
low cycle fatigue
elastic damage
