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利用高温金相显微镜动态观察了GH169合金在疲劳/蠕变复合作用下的变形和断裂过程。结果表明,疲劳/蠕变复合作用下的变形方式有晶内滑移、孪生和晶界滑动,其失效方式因显微组织而不同。沿晶裂纹源于晶界滑动在三叉点处产生的W型裂纹和晶界局部形变区,其扩展机制为空洞的形核、聚集长大和相互连接;穿晶裂纹源于晶内形变损伤区,其扩展机制为沿滑移面的剪切断裂。
The deformation and fracture process of GH169 alloy under the combination of fatigue and creep were dynamically observed by high temperature microscopy. The results show that the deformation modes under the combination of fatigue and creep have intracrystalline slip, twin and grain boundary sliding, and the failure modes vary with microstructure. The grain boundary cracks originate from W-type cracks and grain boundary dendrites generated at the trigeminal point due to the grain boundary sliding. The expanding mechanism is void nucleation, aggregation, growth and interconnection; the transgranular cracks originate from the in-grain deformation damage zone, Its extension mechanism is shear fracture along the slip surface.