镍基高温合金疲劳裂纹急速扩展敏感温度及成因

江河, 佴启亮, 徐超, 赵晓, 姚志浩, 董建新

Sensitive Temperature and Reason of Rapid Fatigue Crack Propagation in Nickel-Based Superalloy

JIANG He, NAI Qiliang, XU Chao, ZHAO Xiao, YAO Zhihao, DONG Jianxin

图4 GH4720Li合金经不同温度疲劳裂纹扩展实验后显微组织的SEM像

Fig.4 Low (a, c, e, g) and high (b, d, f, h) magnified SEM images of GH4720Li alloy after fatigue crack propagation test at 650^oC (a, b), 700^oC (c, d), 750^oC (e, f), and 800^oC (g, h) ( $γ_{I}^{'}$ —primary γ′ phase, $γ_{I I}^{'}$ —secondary γ′ phase, $γ_{I I I}^{'}$ —tertiary γ′ phase)