Thermal Spray Coating Applications in Tribology: Recent Case Studies

Abstract

Thermal spray coating techniques have been rooted deep down in the automotive industry providing groundbreaking solutions for different problems. This technology is capable of optimizing and revolutionizing the face of engineering in tribological applications and associated industrial problems. This paper reviews the development of wear resistant coating on cylinder surface of Al and Mg engine blocks and cylinder bores for improved corrosion and abrasion resistance. Wear mechanism and crack propagation can be prevented by [Cr + (Cr,Al)2O3] nanocomposite coating synthesized by plasma spraying technique which enhances the Al substrate properties by infusion with nanocomposites. This infusion results in the improvement of tribological characteristics. The recent developments in area of wear behavior and tribological characterization are discussed for the high velocity oxyfuel (HVOF) sprayed CrC and CrN coated piston ring applications and engine cylinder accounting for weight reduction, wear rate and the coefficient of friction (COF). The mechanical and tribological properties are compared for HVOF CrC75 (NiCr20)25 coatings sprayed from three different agglomerated feedstock powders with different size distributions.