Effect of structure defects on the surface craters induced by high current pulsed electron beam
结构缺陷对电子束诱发纯铝表面熔坑的影响

The pure aluminum in various pre-deformation extents was irradiated with 4 J/cm2 energy density using a high-current pulsed electron beam (HCPEB) source. The effect of the structure defects on the crater formation was investigated using optical microscopy and scanning electron microscopy (SEM). The temperature rises faster at a subsurface layer than that at the outermost surface due to the maximum energy deposition located at subsurface depth of the beam. The crater distribution density along the grain boundary and slipping band of dislocation were determined. The crater distribution density increases with increasing the pre-deformation extents of the aluminum sample, and the crater prefers to form at the structure defects such as grain boundary and slipping band of dislocation, which seem to be embryos for craters.