Wear Behaviour of Ferrous Based Thermal Spray Coatings on A356

Abstract

Aluminium alloys are becoming a popular choice for engine blocks in automotive industries due to lesser weight as compare to cast iron. Cast A356 Al- alloy, which is a popular choice for automobile engine cylinder block material, has been limited in that use by its poor tribological properties. Many techniques have been explored to solve this problem, including the one addressed in this study, Thermal spray coatings are one of the solutions for improving poor tribological properties of aluminium alloys. In this paper, tribological properties of two types of ferrous based thermal spray coatings were analysed and compared with the cast iron which is a standard material used for cylinder liner. Process used for coating deposition on Al-Si alloy A356 substrate was High Velocity Oxy Fuel (HVOF). The pin and disc tribometer was used to carry out these tests under dry sliding conditions, sliding speed of 1 m/s and 2 m/s, sliding distance of 5000 m and normal load between 9.8 N-73.5 N. Tribological test results showed that, for the investigated conditions coating C-2 had more satisfactory values of wear and friction as compare to C-1 and cast iron, so the former could be adequate substitution for gray cast iron as a material for cylinder blocks.