Graphite Content Change of Powders for Abradable Seal Coatings During Flame or Plasma Process

Change behaviors of graphite content in nickel clad graphite powders during flame or plasma process are studied. Results show that graphite contents of nickel clad graphite particles reduce 11.7% to 24.6% after they pass through flame or plasma torch. NiCrAl composite particles blended in Ni-graphite powder reduce the lose of graphite. Graphite lose is mainly led by the combustion of graphite while nickel-graphite composite particles flying through the torch. Air plasma spray (APS) process brings less graphite loss of nickel clad graphite powder than flame spray. The effect of graphite content on properties of abradable coatings can be accomplished by APS process.