Influence of Spray Process Parameters on Microstructure and Properties of AlSi–Hexagonal Boron Nitride Abradable Seal Coating

Abstract Aluminum silicon hexagonal boron nitride abradable seal coatings were deposited using the atmospheric plasma spraying (APS) process under several processing conditions. In the present study, the effects of process parameters, such as spray power, feed rate, and spray distance, on the microstructure and properties of coatings have been investigated. The microstructure, hardness, bonding strength, chemical composition, and online monitoring of these coatings and flying particles process of the powers were characterized. The results showed that the temperature and speed of the flying particles increased with the increase of power, and the porosity and BN content of the coating were reduced, Therefore, the hardness and bonding strength were improved. Compared with the spraying power, the effect of the feed rate was opposite. With the increase of spraying distance, the influence of particle flight velocity was greater than that of temperature, which resulted in the porosity of the coating and the increase of BN content. The hardness and bonding strength of the coatings were consequently reduced.