Erosive wear characteristic of Mo-TiN composite coatings on turbocharger compressor wheel using Taguchi experimental design

Abstract

In the present work, Mo coating (S1) and Mo–TiN coatings with varied compositions (S2: Mo–5 wt% TiN, S3: Mo–10 wt% TiN, and S4: Mo–15 wt% TiN) were deposited using atmospheric plasma spray system on to Al-Si substrate. The solid particle erosion wear response of these coatings was studied following Taguchi experimental design. The signal-to-noise ratio was analyzed to investigate the influence of operating parameters (torch input power, erodent size, impact velocity, erodent temperature, impingement angle) on the erosion wear rate. In the case of Mo-coatings, erodent size is found to be the most influencing parameter. However, with incorporation of TiN powder to the molybdenum matrix, torch input power level is playing a significant role. Erosion rate is found to be decreased with increasing torch input power in the range of 15–30 kW in Mo-TiN coatings. In Mo–10 wt% TiN coating (S3), the least erosion rate is observed at 30 kW. The surface morphology of the eroded coatings shows less micro-cracks in S3 coating compared to others.