Effect of Transition Layer Thickness on the Bonding Properties of TiN Coating

Abstract

For studying the effect mechanism and regularity of the transition layer thickness on the bonding properties of coatings, TiN coatings were prepared on the surface of titanium alloy through cathodic arc ion plating technology using Ti as the transition layer. The change rules of fracture toughness, micro - hardness, fracture morphology and bonding strength of the coating were studied by adjusting the thickness of the transition layer. Results showed that all TiN coatings showed a preferred orientation along (111) close - packed surface, and the coating fractures presented a columnar crystal structure. As the thickness of the transition layer increased, the fracture toughness of the coating first increased and then decreased, and the fracture dimples gradually became larger and deeper, resulting in a change from inter - granular fracture to trans - granular fracture. Meanwhile, the bonding force of the coating increased first and then decreased, and reached the highest value of 62 N when the transition time was 9 minutes. In general, the Ti transition layer with the optimal thickness could absorb deformation energy, control residual stress, and improve the bonding properties of the coating effectively.

Keywords

• cathode arc ion plating|tin coating|ti transition layer|thickness|fracture toughness|binding properties