Use of high temperature pulsed plasma fluxes in modification of metal materials

The results of the modification of metal materials treated by high temperature pulsed plasma fluxes (HTPPF) with a specific power of incident flux changing in the (3-100) x 10(9) W m(-2) range and a pulse duration lying from 15 to 50 mu s have been presented. Results of HTPPF action were studied on the stainless steels of 18Cr-10Ni, 16Cr-15Ni, 13Cr-2Mo types; on the structural steels of 13Cr, St. 3, St. 45 types; on the tool steels of U8, 65G types, and others; on nickel and high nickel alloy of 20Cr-45Ni type; on zirconium-base alloys and other metals. The microstructure and properties of modified materials (mechanical, tribological, erosion and other properties) and surface alloying of metals exposed to HTPPF action have been investigated. It was found that the material modification by HTPPF resulted in a simultaneous increase of several properties of the units treated: microhardness of the surface and layers of 40-60 mu m in depth, tribological characteristics (friction coefficient, wear resistance), mechanical properties (sigma(y), sigma(0.2), sigma(r)) on retention of the initial plasticity, corrosion resistance, radiation erosion under ion irradiation and others. The determining factor of the changes observed is the formation of the fine cellular structure in the near-surface layers at a depth of 20 mu m with dimensions of the cells changing in the range from 0.1 to 1.5 mu m depending on the kind of material, its preliminary treatment and the parameters of plasma fluxes. (C) 1997 Elsevier Science S.A.