Currently, while light alloys are useful for automotive industries, their weak wear behavior is a limiting factor. The excimer laser carburizing process reported here has been developed to enhance the mechanical and chemical properties of aluminum alloys. An excimer laser beam is focused onto the alloy surface in a cell containing 1 bar methane or/and propylene gas. A vapor plasma expands from the surface, the induced shock wave dissociates and ionizes the ambient gas. Carbon atoms diffuse into the plasma in contact with the irradiated surface. An aluminum carbide layer is created by carbon diffusion in the surface liquid layer during the recombination phase of the plasma. (C) 2002 Elsevier Science B.V. All rights reserved.