Studies on cathodic arc PVD grown TiCrN based erosion resistant thin films

Titanium chromium nitride (TiCrN) coatings with varying Cr content in two configurations, mono- and multilayer, were deposited on high speed steel substrates using a cylindrical cathodic arc physical vapor deposition technique. The physical, mechanical, and erosion behavior of the coatings were investigated. Among the monolayer coatings, the thicker Ti0.48Cr0.52N coatings yielded the best erosion resistance property. But with the increase in thickness, a considerable increase in residual stress is observed. Toward minimizing the stress accumulation, the effect of multilayering with periodic in situ heat treatment (after each 1 μm film growth) was studied by growing films in Ti0.52Cr0.48N/Ti0.40Cr0.60N bilayer configuration. A new approach based on % area of erosion damage for measuring relative wear rate of thin films has been proposed and implemented. The multilayer coatings exhibited superior erosion performance compared to the well-known erosion resistant TiN coatings that are in use for compressor blades from past few decades. Further, the erosion failure mechanisms in TiCrN coatings were also studied and found to be clearly different for mono- and multilayer configurations. The results reveal that the thicker multilayer TiCrN coatings (20 μm) exhibit promising choice for erosion resistance applications.