Modification of titanium by high power electron beams

Irradiation of titanium was performed with high power electron beams. The electron energy was 800 keV, the pulse duration was 10 ns and energy density injected into the sample by one pulse was 20 J cm(-2). Hardness measurements of irradiated samples permit the detection of two different modified layers. The hardness of these two layers depends on the pulse number. The states of stress and the grain size in irradiated samples were determined by X-ray diffraction. XRD shows the presence of the high pressure omega phase in titanium after power electron beam exposure. The explanation of the results is based on stress waves, which arise due to such exposures. The observed hardening of irradiated titanium is a result of an intensive process of twinning produced by shear stress waves. (C) 1999 Elsevier Science S.A. All rights reserved.