Enhancing longevity and performance: The effects of ZrO2 and TaC coatings on pistons in internal combustion engines

Coating of pistons with ZrO2 and TaC improves their longevity and performance in internal combustion engines by enhancing the resistance to wear, heat and corrosion. In this study the plasma spray coating is performed on crown of the piston with the combination of the percentage composition namely, 95 % ZrO2 + 5 % TaC, 98 % ZrO2 + 2 % TaC and 100 % ZrO2. Among the three 95 % ZrO2 + 5 % TaC composition shows better results. The increase in ZrO2 content leads to the formation of a more integrated scale with fewer pores. Higher concentrations of ZrO2 in the coatings lead to the increased interaction with discharge sparks and instability of the process. At elevated temperatures, a two-phase material of cubic zirconium dioxide and hexagonal corundum was formed. The bonding strength of the coating is influenced by the addition of TaC and the power input during the spraying operation. The microstructure of ZrO2 and TaC coatings on aluminium alloy is characterized by granular structure, tightly packed pores and partially melted ZrO2 particles. The coating had a uniform structure with columnar and cluster-like elements, influenced by ZrO2 concentration.