【摘要】 利用扫描电镜（SEM）原位拉伸,观察了 Fe-3％Si 单晶体裂尖的变形和断裂过程。用网格法加计算机处理系统测出了裂纹尖端的应变场及氢对应变分布的影响。发现在Ⅰ型载荷下,主裂纹尖端应变呈不对称分布,形变带内应变梯度很大。形变带内应变分布为: ε_yy=f（x）exp（-Ar）.氢不改变裂纹尖端塑性变形特征,但能明显促进裂纹尖端局部塑性变形的非均匀增加。更多还原

【Abstract】 The deformation process and the strain field ahead of crack tip in Fe-3% Si single crystal were studied with SEM, grid method and computer image processing The distribution of strain field in plastic band around the crack tip is characterized by εyy= f(x)exp(-Ar) The general feature of the plastic deformation is similar in both charged or uncharged hydrogen specimens. However, the presence of hydrogen enhances the localized plastic band inhomogeneity and significantly increases the plasticity in high deep strain areaThe deformation process and the strain field ahead of crack tip in Fe-3% Si single crystal were studied with SEM, grid method and computer image processing The distribution of strain field in plastic band around the crack tip is characterized by εyy= f(x)exp(-Ar) The general feature of the plastic deformation is similar in both charged or uncharged hydrogen specimens. However, the presence of hydrogen enhances the localized plastic band inhomogeneity and significantly increases the plasticity in high deep strain area更多还原