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研究了总应变控制下比例加载和不同相位差(45°和90°)的非比例加载条件下GH4169镍基高温合金650℃双轴疲劳的断口特性.结果表明,比例加载时,裂纹在试样表面均匀萌生;随非比例度提高,裂纹萌生的数量明显减少.比例加载的断口表面有明显的撕裂条带,且沿径向扩展;而非比例加载时这些撕裂条带减少,相应地撕裂面增多,在相位差为90°时断口表面完全为撕裂面,且沿圆周方向扩展.在两裂纹扩展的交界处,发现有疲劳条纹,沿径向分布.在瞬间断裂区,随着非比例度的增加,韧窝逐渐加深,且撕裂面逐渐加大.
The fracture characteristics at 650 ℃ of GH4169 nickel base superalloy under proportional strain and non-proportional loading (45 ° and 90 °) under total strain control were studied.The results show that when the specimen is loaded proportionally, And the number of crack initiation decreased obviously with the increase of non-proportional degree.On the surface of the proportionally loaded fracture surface, there were obvious tear bands and radially expanded, while those of non-proportional load decreased, correspondingly When the phase difference is 90 °, the fracture surface is completely tearing surface and extends in the circumferential direction. At the boundary between the two cracks, there are some fatigue stripes which are distributed in the radial direction. In the instantaneous fracture zone, With the increase of non-proportional, dimple gradually deepened, and tear surface gradually increased.