Surface Hardening of Aluminium by Laser alloying with Molybdenum and Zirconium powder

摘要

Aluminium is one of the common elements that has attracted researcher all over the world because ofthe light weight to strength, but the hardness values and wear resistance is low which limited usage inthe area of applications. This research work is based on the surface hardening of aluminum by laseralloying with binary combinations of molybdenum and zirconium metallic powders. The laser wasperformed with 4.4 kW Rofin Sinar Nd:YAG. The laser alloyed surfaces produced were characterizedusing standard techniques. The electrochemical, wear and micro-hardness tests were used to determinethe possible area of application. The results showed that laser alloying of aluminium with molybdenumand zirconium metallic powders enhanced the hardness values, wear and corrosion resistance. Thehardness values of 6-times and wear resistance of 16-stimes were obtained over the substrate atoptimum condition of 50%Mo and 50% Zr, laser power of 4 kW and speed of 1.4 m/min. The variousmicrostructures obtained were the main factor responsible for the improvement in properties. Thisresearch work has established that binary combinations of molybdenum and zirconium powders can beused to enhance the properties of laser alloyed aluminium.