Laser Surface Modification of Metals and its Tribological Applications

Several methods and technologies for laser surface treatment of metals are reviewed in this paper. The tribological applications of this treatment and its future development are briefly discussed. Laser transformation hardening provides the treated workpieces with hard mar- tensitic surface that has compressive stresses. Hence, reduction in wear rate of treated surfaces is achieved. Laser cladding offers feasibility to apply high anti-wear, anti-corrosive and heat-resisting cladding alloys as well as ceramics on workpieces, the good tribological properties will be obtained by reducing the amount of dilution of cladding alloy with the workpieces. Laser alloying offers the possibility to produce high performance surfaces by selecting the alloying elements and substrate. Laser glazing gives potential to enhance wear-resistance by refining grain structure, reducing segregation, producing supersaturation solid solution body and metastable or amorphous phases. Laser shock hardening may change the structure and properties through forming shock wave and causing damage in the surface layer of metal.