Influence of Interfacial Laser Processing on Delamination Strength of Sprayed Film

Abstract

In order to investigate the influence of laser processing on interfacial fracture toughness of coatings, a convex edge-indent test was carried out on the specimens. The surface of the aluminum alloy plate with various curvatures were laser processed to create straight grooves, and Cr₃C₂-NiCr and WC-Co coatings were thermal sprayed on the plates. The convex edge indent test was carried out by pressing a conical diamond indenter from the surface of the convex shaped specimen at a distance from the edge. The results showed that the load lineally increased with increasing indentation depth, and delamination occurred at the maximum indentation load. The delamination loads of the Cr₃C₂-NiCr coating were larger than those of the WC-Co coating. The measured interfacial fracture toughness of the Cr₃C₂-NiCr coating also showed larger values than that of the WC-Co coating.