【摘要】 对面心立方结构多晶纯铜和纯铝在低周冲击疲劳载荷下循环形变的微观机制进行了研究。疲劳过程中用扫描电子显微镜 (SEM )对试样表面进行观察 ,结果表明 :在冲击疲劳载荷下 ,滑移和孪生是面心立方金属变形的主要方式。疲劳初期 ,纯铜试样表面还出现晶粒的弹性凹凸变形。孪晶和晶粒凹凸变形这类瞬态或快速形变机制的发生 ,是冲击疲劳不同于常规疲劳的显著特点更多还原

【Abstract】 A study has been performed relating to the micromechanisms of cyclic deformation in polycrystalline copper and aluminium under low cycle impact fatigue (LCIF) loading. In fatigue process the surface topography of specimen was observed by scanning electron microscope. The results show that in LCIF the primary mechanisms of cyclic deformation are slip, twinning. And the concave-convex deformation of grains surface occurred in the early stage of fatigue in copper.It is the distinct feature of LCIF that the frequent appearance of rapid and instant response mechanism such as twinning and elastic distortion.更多还原