EFFECT OF HEAT TREATMENT ON THE TRIBOLOGICAL PROPERTIES OF PVD-COATED TiAlN COATINGS DEPOSITED ON STAINLESS STEEL SUBSTRATE

Understanding the effect of heat treatment on the wear resistance of physical vapor deposition (PVD)-coated materials is vital for industries such as machining, metalworking, and aerospace, which shall help in increased productivity. Hence, this study investigates the influence of heat treatment on the mechanical and tribological behaviors of PVD TiAlN coatings on 316L stainless steel substrate. The coated samples were subjected to annealing heat treatment by heating them to 500∘C, 600∘C, 700∘C, and 800∘C, respectively, for a duration of 2 h and subsequently cooling them in air to room temperature. Wear tests were conducted using a ball on disc configuration with a 6 mm diameter alumina ball as a counterface in a 3.5 wt.% NaCl solution. This specific testing environment simulates corrosive conditions typical of marine and industrial applications, highlighting the relevance and novelty of this study. Nanohardness measurements on the samples indicated a reduction in hardness with an increase in the heat treatment temperature. The coefficient of friction (COF) is observed to increase with the heat treatment temperature, primarily due to the formation of oxide layers on the surface, except for the 800∘C treatment, which exhibited a significant decrease in wear resistance. Notably, the wear resistance of the coated samples improved with increasing heat treatment temperature, except for the 800∘C treatment, which exhibited a significantly low wear resistance. The enhanced wear resistance observed at lower temperatures is attributed to the formation of oxide layers at the interface between the coating and the alumina ball, reducing wear and improving the coating’s durability.