Effect of Laser Surface Texturing on Coating Adherence and Tribological Properties of CuNiIn and MoS2 Coating

Copper nickel indium (CuNiIn) and Molybdenum disulphide (MoS2) duplex coating is used in aero engine compressor blades of Ti6Al4V to prevent fretting failure. Surface before coating is roughened by grit blasting process for coating adhesion. In present study, in place of grit blasting, laser surface texturing (LST) process is used for surface preparation and compared with grit blasted surface. Four different elliptical and square patterns are created by LST on Ti6Al4V. Difference of surface topography between LST and grit blasted surface is analyzed by SEM and white light interferometery. CuNiIn is deposited on Ti6Al4V by atmospheric plasma spray. MoS2 lubricating coating is deposited on top of CuNiIn by spray painting and curing. Effect of difference in surface preparation on coating microstructure as well as on tribological properties is studied. The results showed that geometry and dimensions of LST pattern influence the coating adherence and wear performance. LST process can be optimized for better performance and explored as an alternative surface preparation process in industry for thermal spray coatings.