Electrodeposition of Ni-La2O3 composite on AA6061 alloy and its enhanced hardness, corrosion resistance and thermal stability

In this work, the microstructure, microhardness, corrosion behavior and thermal stability of Ni-La2O3 composite on AA6061 aluminum alloy were studied. Corrosion behavior was studied with 3.5 wt% NaCl solution at room temperature in a static electrolyte condition. Ni-La2O3 showed nobler corrosion potential than the pure nickel and aluminum alloy and a maximum microhardness of 750 HV (Vicker's hardness) was observed at optimized conditions. It is evident that the incorporation of La2O3 in the Ni metal matrix leads to the corrosion resistance and the hardness improvement. Thermal stability was studied by using differential scanning calorimetry (DSC) as well as annealing at constant temperature of 500 °C for 5 h in a furnace and it shows better thermal stability of the composite. Electrodeposited Ni-La2O3 composites were characterized by SEM/FESEM, EDS, XRD and electrochemical techniques.