等离子喷涂距离和氩气流量对MoSi_2 涂层结构的影响

以MoSi_2粉末为喷涂原料,采用大气等离子喷涂技术,在K403镍基合金表面制备了二硅化钼涂层,考察了不同喷涂距离和氩气流量对MoSi_2涂层的相组成和微观组织的影响.结果表明,随喷涂距离的增加,涂层的相组成由富硅相向富钼相演变;氩气流量的增大可减少涂层中的富钼相,但若流量过大,则会降低涂层的致密性;采用喷涂功率为30 kW、喷涂距离为100 mm和氩气流量为50 L/min的喷涂工艺可制备出以MoSi_2为主相且致密性较高的涂层,明显提高了基体的高温抗氧化性.

Effects of Plasma Spraying Distance and Argon Flow on Coating Structure of MoSi_2

Using MoSi_2 powder as spraying material, MoSi_2 coating was prepared on the surface of K403 nickel-base alloy by atmospheric plasma spraying technique. The effects of different spraying distance and argon flow on phase composition and microstructure of MoSi_2 coating were investigated. The results showed that phase composition of the coating changed from Si-rich phase to Mo-rich phase with the increase of the spraying distance. The increase of argon flow can reduce Mo-rich phase in the coating, however, if the flow is excessive, the coating compactness decreases. The coatings with high compactness and MoSi_2 as main phase were prepared by the spraying process with 30 kW spraying power, 100 mm spraying distance and 50 L/min argon flow, which obviously improved the high temperature oxidation resistance of the matrix.