Analysis on Residual Stress in TiN Coating with Different Thicknesses

Abstract

TiN coating is often coated on fine blanking tools made of with the powder metallurgy high speed steel S790 by Multi-arc ion plating. The phase variation, residual stress and microhardness of TiN coatings were respectively analyzed by X-Ray Diffraction(XRD) and Vickers hardness tester in this research. The result shows that: there is obvious preferred orientation in the crystal surface (1 1 1) and (2 2 2) of TiN coating, the residual stress of TiN coating ranges from -2 347 MPa to -1 920 MPa, and that of the substrate from -154.9 MPa to -69.21 MPa, both of which decrease with the increasing of coating thickness. The TiN coating on the S790 substrate was annealed at temperature 500°C for one hour. It was revealed that the stress state of TiN coating was better and thus the properties of the TiN coating were improved.