Crater Formation on the Surface of Pure Metal and Alloy Irradiated by High Current Pulsed Electron Beam

Abstract

A detailed investigation concerning the formation mechanism of craters of pure metal and alloy surface after high-current pulsed electron beam (HCPEB) processing has been carried out. After HCPEB irradiation, typical craters were homogeneously distributed on the entire surface of 3Cr13 stainless steel, resulting from local sublayer melting and eruption through the solid outer surface. Comparatively, almost no craters were created of pure zirconium, which was associated with the shallow melting site and incomplete treated surface. Furthermore, a large number of ultrafine grains were formed on the irradiated surface, indicating that surface melting was the dominant interaction mechanism between HCPEB irradiation and pure zirconium. It is apparent that "crater free" phenomenon plays a dominant role in surface modification of zirconium and zirconium alloys.