Study on crack behavior of laser cladding ceramic-metal composite coating with high content of WC

摘要

? 2022 Elsevier Ltd and Techna Group S.r.l.The purpose of this work is to investigate the cracking behavior and crack formation mechanism of high WC wt composite coatings. Three NiCrSiBC-WC composite coatings with respective WC wt of 40, 50, 60 were prepared on carbon steel substrates by laser. The macro- and micro-morphologies together with phase compositions of three coatings were comparatively observed. Further, the hardness, residual stress and toughness values of three coatings were tested and calculated quantitatively to get a clear understanding of crack formation. As a result, cracks occurred in 50 and 60WC coatings but not being found in 40WC coating. With increasing WC wt, grains were more refined while more cracks occurred. The cracking of 50WC coating was attributed to high tensile residual stress coupled with low toughness. Whereas compared with 50WC coating, the higher crack susceptibility of 60WC coating was mainly because of further increased residual stress.