TREATMENT OF METALLIC MATERIALS USING LAS ER SHOCK PRODUCED IN CONFINED GEOMETRY AT 248 NM

We report here some preliminary results of a study concerning basic ph ysical and metallurgical processes involved in laser-shock treatment o f materials. This laser shock processing consists of the use of a high power pulsed 248 nm excimer laser to generate a short duration, high amplitude pressure which propagates inside various metallic samples, a luminium, titanium and iron alloys. Pressure measurements on the rear side of the sample have been obtained in direct ablation and water-con fined plasma regimes. Experimental results are compared with an analyt ical model. Surface hardness, in-depth residual stresses and fatigue t ests have to be compared in both the interaction regimes.