Thermal spray coating of abradable Ni based composite

Abstract

Abradable clearance control coatings of compressor and turbine casing of aircraft engines are designed to wear in performance to the opposing blade tip or other moving parts. In the present work the mild steel surface has been coated with KNA (boron nitride, nickel, silicon and carbon) using thermal spray coating technique. The feed rate of the coating material has been optimised or the required hardness of 15 to 25 kg mm-2. The coating has been characterised for porosity, coating thickness, adhesion strength, deposit efficiency and hardness in order to analyse the performance of the coating. Scanning electron microscopy has been carried out to observe the microstructure of the coating and distribution of boron nitride particles. © 2009 Institute of Materials.