Effect of laser surface melting on surface integrity of Al-4.5Cu composites reinforced with SiC and MoS2
(1. Department of Mechanical Engineering, Karunya Institute of Technology and Science, Coimbatore, Tamil Nadu 641114, India;
2. Department of Mechanical Engineering, National Institute of Technology Manipur, Imphal 795004, India;
3. Department of Mechanical Engineering, Indian Institute of Technology Guwahati, Assam 781039, India)
2. Department of Mechanical Engineering, National Institute of Technology Manipur, Imphal 795004, India;
3. Department of Mechanical Engineering, Indian Institute of Technology Guwahati, Assam 781039, India)
Abstract: Two types of composites were prepared with Al-4.5Cu alloy as a matrix using stir casting method. One was reinforced with 10 wt.% of SiC and 2 wt.% of MoS2. The other was reinforced with 10 wt.% of SiC and 4 wt.% of MoS2. Their surfaces were remelted using a CO2 laser beam with an objective to study the influence of laser surface melting (LSM). The topography, microhardness, corrosion resistance and wear resistance of the laser melted surfaces were studied. Overall surface integrity after LSM was compared with as-cast surface. LSM enhanced the microhardness and wear resistance of the surface in each case. Porosity of the laser melted surface was low and corrosion resistance was high. Thus, LSM can be conveniently applied to enhancing the surface integrity of the aluminium composites. However, there is an optimum laser specific energy, around 38 J/m2 in this study, for obtaining the best surface integrity.
Key words: aluminium composites; silicon carbide; molybdenum disulfide; laser surface melting; microhardness; corrosion resistance