摘要
研究了高温合金GH4169惯性摩擦焊(IFW)焊接接头在室温(23℃)和高温(650℃)下的疲劳裂纹扩展规律。利用金相显微镜(OM)、扫描电镜(SEM)对合金的显微组织和断口形貌进行观察分析。结果表明:在相同温度下,焊缝的裂纹扩展速率低于母材的裂纹扩展速率,这是由于焊缝中的晶界及第二相对裂纹的阻碍效应较强所致。随着温度的升高,母材及焊缝的裂纹扩展速率明显加快,这是由于在高温下晶界弱化,且裂纹尖端加速氧化以及屈服强度和弹性模量降低的共同作用的结果。
The fatigue crack growth tests on different zones of inertia friction welded （IFWed） joints of GH6149 alloy were carried out at 23℃ and 650℃ temperatures,respectively.The microstructure and fracture surfaces were observed by OM and SEM.The results show that the fatigue crack growth rate（FCGR） of IFWed weld metal（WM） is lower than that of base metal（BM）,due to the interaction of fine-grain strengthening and brittle precipitations.FCGR of three different zones of IFWed joints all increase along with the rise of temperature,resulting from the weakening crystal and grain boundary,accelerate oxidization in front of crack tip and the decrease of yield strength and elastic modulus at high temperature.
出处
《航空材料学报》
EI
CAS
CSCD
北大核心
2013年第6期45-50,共6页
Journal of Aeronautical Materials
