Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10675775 | Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms | 2005 | 7 Pages |
Abstract
High current pulsed electron beam (HCPEB) is now developing as a useful tool for surface modification of materials. When concentrated electron flux transferring its energy into a very thin surface layer within a short pulse time, superfast processes such as heating, melting, evaporation and consequent solidification, as well as dynamic stress induced may impart the surface layer with improved physico-chemical and mechanical properties. This paper presents our research work on surface modification of steels and magnesium alloy with HCPEB of working parameters as electron energy 27 keV, pulse duration â¼1 μs and energy density â¼2.2 J/cm2 per pulse. Investigations performed on carbon steel T8, mold steel D2 and magnesium alloy AZ91HP have shown that the most pronounced changes of phase-structure state and properties occurring in the near-surface layers, while the thickness of the modified layer with improved microhardness (several hundreds of micrometers) is significantly greater than that of the heat-affected zone. The formation mechanisms of surface cratering and non-stationary hardening effect in depth are discussed based on the elucidation of non-equilibrium temperature filed and different kinds of stresses formed during pulsed electron beam melting treatment. After the pulsed electron beam treatments, samples show significant improvements in measurements of wear and corrosion resistance.
Keywords
Related Topics
Physical Sciences and Engineering
Materials Science
Surfaces, Coatings and Films
Authors
Shengzhi Hao, Bo Gao, Aimin Wu, Jianxin Zou, Ying Qin, Chuang Dong, Jian An, Qingfeng Guan,