摘要
对镍基高温合金GH4049在相同载荷、不同温度下疲劳小裂纹扩展规律进行了试验,利用复型技术和光学显微镜观测了裂纹尺寸演化全过程,发现小裂纹扩展速率的趋势是先快后慢,且温度升高,扩展速率反而下降。这与小裂纹的闭合效应有关,在700℃小裂纹的氧化诱发闭合效应比650℃时明显。
Propagation behaviour of the small fatigue cracks in Ni-base superalloy GH4049 at high temperature was researched. The evolution process of cracks＇length was observed by using replication method and optical microscopes. The experiment results indicate that the small crack growth rate is rapid at first, and become slow then. Its growth rate decreases with the increase of the temperature, and is quite different from that of the large cracks. This is associated with the closure effect of small cracks. The effect of the oxide-induced closure at 700℃ is more obvious than that at 650℃.
出处
《金属热处理》
EI
CAS
CSCD
北大核心
2005年第11期38-40,共3页
Heat Treatment of Metals
基金
国家自然科学基金项目(50041010)
关键词
镍基高温合金
高温疲劳小裂纹
裂纹扩展速率
裂纹闭合效应
Ni-base superalloy
high temperature small fatigue crack
crack growth rate（CGR）
crack closure effect
