Characterization and adhesion strength study of detonation-sprayed MoB-CoCr alloy coatings on 2Cr13 stainless steel substrate

A novel MoB-CoCr alloy coating was deposited onto stainless steel (2Cr13) substrate using a detonation gun (D-gun) spraying technique. Microstructures of the powder and coating were investigated by X-ray diffraction (XRD), scanning election microscopy (SEM), and transmission electron microscopy (TEM), and a quantitative determination of the adhesion strength of the coating was calculated by combination of modified four-point bending (4PB) test and finite element analysis (FEA) simulation. The results show that the coating mainly consists of ternary transition metal boride matrix phases (CoMo2B2, MoCoB) and binary borides (MoB and CrB). Nanocrystalline grains with a size of 50-100 nm were observed in the coating. The average energy release rate and phase angle are 191.2 J m(-2) and 41.7A(0), respectively, which show strong bond strength compared to other reported values.