Effect of Ni-Coated Reinforcement on Mechanical and Tribological Properties of Heat Treated Aluminium Composite

Abstract

The present work focusses on improving the mechanical and tribological properties of Al-5Si-3Cu alloy and Ni-coated TiC reinforced composite fabricated through liquid metallurgy route, through T6 heat treatment. Good interfacial bonding was developed between the matrix and coated reinforcement on microstructural investigation. There was an improvement in hardness for heat-treated alloy and composite by 34.5% and 14.7% respectively. Tensile strength for heat-treated alloy and composite was enhanced by 25.9% and 30.6% respectively. Pin on disc dry sliding wear test was carried out for Ni-coated TiC heat-treated composite for varying loads (10, 20, 30N), distances (500, 1000, 1500m) and velocities (1, 2, 3m/s) by using Taguchi's L27 Orthogonal Array. It was concluded that load had the highest influence on wear rate (71.88%), whereas the effects of sliding distance (8.23%) and velocity (3.45%) were nominal. Wear analysis revealed that, wear rate increased with an increase in load and sliding velocity and decreased with increasing sliding distance. Defects like delamination, grooving, and protrusions were observed on the worn surface. Thus, this kind of Ni-coated TiC reinforced composites can be used in camshafts, bearings and bushes for better wear resistance.

Keywords

• liquid metallurgy
• electroless nickel coating
• heat treatment
• dry sliding wear
• taguchi method