Abstract
Mild steel specimens of 0.2% C were laser cladded using YAG Fiber laser at processing power of 2800 W and travelling speed of 4 mm/s. To prevent the oxidation, argon gas was used as a shielding gas. SiC and Al2O3 powders of 1.25 mu m particle size were used as reinforcement. Cladded, fusion and heat affected (HAZ) zones were produced. Composites reinforced with SiC were produced in cladded and fusion zones. In the cladded zone, long and parallel SiC dendrites were formed in martensitic matrix. Also, in the fusion zone, SiC dendrites formed in martensitic matrix. In the HAZ and near the fusion one, a mixture of pearlite with high percentage and bainite structures were resulted. In this case, the surface hardness of the cladded layer was improved as almost seven times as that of the substrate. In the second case, composites produced by dispersing Al2O3 particles in mostly martensitic matrix with coarse grains and some pores. The surface hardness of the cladded layer was improved as almost two times as that of the substrate. Hardened zones of 0.8 mm depth were produced. The wear resistance of the samples cladded with both powders (SiC and Al2O3) was improved. However, the effectiveness of SiC in wear reduction is higher than that of Al2O3 particles.