The partial surface of a certain intermediate diffusion casing part needs to be sprayed with a chromium carbide-nickel-chromium-aluminum-yttrium coating to improve its wear resistance.
Two kinds of nickel-chromium-aluminum-yttrium powders with particle sizes (53～106μm and 23～53μm) are used as the coating.
Layer the bottom layer, and use the explosive spray method to spray the bottom layer and the surface layer.
Use the scanning electron microscope (SEM), microhardness tester and electronic tensile testing machine to spray the metallographic structure and composition of the coating prepared by spraying the bottom powder of different particle sizes.
The composition, hardness and bonding strength are analyzed and compared.
The results show that the performance of chromium carbide-nickel-chromium-aluminum-yttrium coatings prepared by two kinds of nickel-chromium-aluminum-yttrium powders can meet the technical requirements.
In contrast, the thickness uniformity of the nickel-chromium-aluminum-yttrium bottom layer prepared by the finer particle size powders It is better, and the content of unmelted particles and interface pollution is slightly lower, and the bottom bulge formed after spraying of the coarser particle size powder will produce a shielding effect, which affects the interface combination between the bottom layer and the surface layer, which is expressed as a coarse particle size powder The bonding strength of the prepared coating is 39.
7MPa and the hardness is 598.
1HV; while the bonding strength of the coating prepared by the fine particle powder is 58.
7MPa and the hardness is 615.