Paper MG+AS+EM+NS+SA+SE+SP+SS+TF-FrM6
Erosion Resistant Physical Vapor Deposition Coatings for High Temperature Polymer Matrix Composites Applications

Friday, November 1, 2013, 10:00 am, Room 202 B

The advantages of replacing metals in aircraft turbine engines with High-Temperature Polymer Matrix Composites (HTPMC’s) include weight savings accompanied by high strength to weight ratio, and lower manufacturing costs. Most of the nacelle of a modern aero gas turbine is made of HTPMC, a component that accounts for approximately 25% of the weight and 20% of the cost of the power plant. Unfortunately, they are limited to applications where they are not exposed to high-temperature oxidizing atmospheres and/or particulates from ingested air. This is because oxidation and erosion occur on the surface, leading to weight loss, and/or cracking on the surface and a consequent decline of mechanical properties over time. Resistance to surface erosion is one rarely reported property of HTPMC’s in engine applications because HTPMC's are generally softer than metals and their erosion resistance suffers.

Although prior research has shown that oxidation can be slowed down when metallic or ceramic coatings are applied onto HTPMC’s, there remains a need for erosion-resistant coatings that protect HTPMC's from high-velocity particulates in the engine flow path. These erosion-resistant coatings could extend the life of polymer composites and also reduce the overall cost of the turbine assembly. Hence in this paper we report the development of coating materials that are compatible with HTPMC’s such as Avimid N and AFR-PE-4 using Cathodic Arc Physical Vapor Deposition (CAPVD). We report the feasibility of applying multilayer PVD TiN coatings onto the HTPMC substrates and characterize their adhesion, microstructure and erosion resistance. We also show the effectiveness of duplex process of thermal spray and PVD to enhance the overall adhesion of the multilayer coating.