P Hosseini Tehrani - Automotive Dept., Iran University of Science and Technology
M. H. Shojaeefard
K. Khorshidi

Technological advances necessitate the use of material in increasingly extreme and aggressive conditions, such as corrosive atmospheres and abrasive wear situations. Laser hardening is widely used to improve the mechanical properties of highly stressed, ferrous and non ferrous machine parts. Surface hardening increases wear resistance and fatigue life through micro structural changes induced in the metal surface during laser processing[IIJ. Output beams are easily shaped by optical components into squares, circles, lines orinto more complex axi-symetric shapes for special purposes. This makes it easy to heattreat not only nat surfaces. but also complex curved surface, such as bearing races, gears, shafts, cylinders, camshafts and so on. Pulsed laser surface modification has been identified as one of the promising technologies for enhancing surface properties. This technique includes shock and pulsed transformation hardening. In this paper considering temperature and pressure dependent material constants. stress and strain fields are illustrate. It is shown that compressive residual stress would occur near the surface as a result of laser shock surface treatment. Compressive residual stress may improve surface hardening and fatigue life.

Laser Shock, Wave, Hardening,Thermoelastoplasticity,