【摘要】 研究了六方金属纯锌和TC4钛合金在低周冲击疲劳载荷下的循环变形和损伤机制。在疲劳过程中用扫描电子显微镜(SEM)对试样表面形貌进行跟踪观察。发现六方金属在冲击疲劳载荷下变形的主要形式是孪生;TC4钛合金沿孪晶界发生"挤出",微裂纹沿挤出脊形成,并沿孪晶界按Z字形扩展。另外,在纯锌试样表面上可以观察到普遍的畸变和翘曲。更多还原

【Abstract】 A study has been performed on micromechanisms of cyclic deformation and fatigue damage in pure Zinc and TC4 Titanium alloy under low-cycle impact fatigue (LCIF) loading. In LCIF process the surface topography of specimens were observed by SEM. The results show that under LCIF the dominative mechanism of cyclic deformation is twinning, and in TC4 the extrusion occurred along twins boundary. Micro crack was initiated at extrusion ridge and grew along it in Zigzag. In addition, in Zinc a widespread distortion and warp of grain surface occurred.更多还原