1. Introduction

Laser heating offers considerable advantages over the conventional methods such as precision of operation, local treatment, and low cost. Laser at high intensity when interacts with the solid surface, the absorption takes place. This in turn causes internal energy gain of the substrate material and heat release from the irradiated region. Since the process, in general, is fast, temperature gradients remain high in the irradiated region. This results in high thermal strain and thermally induced stresses in this region. Moreover, in laser treatment process, the end product is important from the application point view. The high stress levels formed in the irradiated region may cause failure of the surface through stress induced cracking. Consequently, a care needs to be taken during the laser treatment process. This chapter provides the information about the importance and limitations of the laser treatment process in terms of the thermal stresses formed in the irradiated region.