Abstract: In order to study the effect of matrix surface microstructure on the adhesion between coating and matrix, the adhesion between coating and matrix was tested. The hardness of the coating was measured. The interfacial microstructure between coating and matrix,and the matrix surface microstructure were observed. The relationship between adhesion and surface morphology was analyzed. The results show that after water blasting and dry blasting, V-grooves are formed on the matrix surface, which are expressed as type θ₁ and type θ₂ respectively（θ₁<θ₂, θ is the ratio of groove opening width to groove depth）. The matrix surface microstructure can significantly affect the adhesion between coating and matrix. But the phase, density and residual stress of coating are not influenced. According to the nucleation mechanism, the atoms will nucleate and grow at the upper edge of θ₁ “V” groove. A large number of atoms are blocked, resulting in hollow bottom of “V” groove. In θ₂ “V” groove, a large number of atoms enter the groove. With the diffusion of atoms, the almost completely filled“V” groove is formed. As a result,the bonding area of coating and matrix increases, and the adhesion of coating and matrix improves.

Key words: coating, surface microstructure, PVD, adhesion, "V"groove