LIE Home • Issue Contents

Laser Microtexturing of NiCrAlY Coated Nickel-based Superalloy for Improved Adhesion Bond Strength
F.P. Prakash, M. Duraiselvam, S. Natarajan and K.G. Balamurugan

A Q-switched Nd:YAG laser was used to microtexture the surface of C-263 nickel-based superalloy with chevron dimple, waviness groove and linear groove textures. A NiCrAlY coating was deposited over the grit blasted and textured surfaces by air plasma spraying. The surface roughness and adhesive bond strength of textured and grit blasted specimens were evaluated. The results indicate that the laser surface microtexturing improves the surface roughness by around 85% over a grit blasted specimen. The surface roughness of the textures varies with the contact area. The laser surface microtextured specimens show approximately 92% increase in adhesive bond strength over a grit blasted specimen. The adhesive bond strength of the laser microtextures depends on the NiCrAlY coating deposition nature and adhesion ratio. The absence of a recast layer was noted as improving the NiCrAlY coating deposition. The heaviness groove microtexture shows higher adhesive bond strength with higher adhesion ratio and adequate NiCrAlY coating deposition. The chevron dimple microtexture shows lower adhesion bond strength due to lower adhesion ratio and inadequate NiCrAlY coating deposition.

Keywords: Nd:YAG laser, air plasma spraying, nickel-based superalloy, C-263, NiCrAlY coating, laser surface texturing, microtexturing, adhesive bond strength

Full Text (IP)