Erosion Resistance of Thick Nitride and Carbonitride Coatings Deposited using Plasma Enhanced Magnetron Sputtering

Abstract

In this paper, we report the microstructural and erosion test results of thick coatings deposited using a PEMS technique. Nitrides (TiN, CrN, and ZrN) and nanocomposite carbonitride (TiSiCN) were deposited on Ti-6Al-4V disk coupon and turbine blade samples. The samples were analyzed using SEM with energy dispersive EDS, nanoindentation, and XRD. Selected samples were subjected to alumina erosion tests separately using two incident angles (30° and 90°, respectively). The nanohardness of the nitride coatings was 30 GPa for carbonitride. It was observed that at 30° TiSiCN renders the best erosion resistance. At 90° incidence, the erosion damage becomes more severe. However, one TiSiCN sample still showed an order of magnitude improved erosion resistance over the commercial TiN while delamination occurred on other samples. The delamination is believed to be the result of high internal stress of the TiSiCN coatings. A multilayered TiSiCN/Ti coating is proposed to maintain the high erosion resistance while reducing the internal stress. It is believed that this technology, once fully developed, may be applied to protect turbine engine blades and vanes from both solid particle erosion (SPE) and liquid droplet erosion (LDE) as well as piston rings of heavy-duty diesel engines from wear.