摘要
采用单边缺口试样对316L不锈钢扩散连接接头进行显微疲劳试验,实现微观尺度下界面裂纹扩展和微孔隙演化的原位观测.试验观察表明:动载荷下界面裂纹扩展时,裂纹尖端晶粒内产生局部的塑性变形,但几乎观测不到界面微孔隙的扩展,也未见微孔隙与微孔隙的相连;微孔隙对界面裂纹萌生和扩展的影响不大;扩散连接过程中所形成的谷脊状界面可以改变裂纹的扩展路径.
Micro-fatigue test was performed on a single-edge notched specimen of diffusion bonded joints of 316L stainless steel in order to realize the in-situ observation of interfacial crack growth and microvoids evolution on microscale. Test results show that there is no shape change in microvoids as the crack propagates under dynamic loads,and plastic deformation occurs in grains adjacent to the crack tip. No coalescence among microvoids is observed during the repeated tests. Microvoids have little effect on the initiation and propagation of interfacial fatigue crack. The ridge-like interface formed in diffusion bonded joints due to surface roughness will change the crack path and can resist the growth of fatigue crack.
出处
《材料科学与工艺》
EI
CAS
CSCD
北大核心
2010年第1期141-144,共4页
Materials Science and Technology
基金
国家自然科学基金(50225517
50475068)
教育部霍英东青年教师基金(101054)
关键词
扩散连接接头
界面疲劳裂纹
显微疲劳试验
裂纹扩展
微孔隙
diffusion bonded joints
interfacial fatigue crack
micro-fatigue test
crack propagation
microvoids
