Adhesion strength and high temperature wear behaviour of ion plating TiN composite coating with electric brush plating Ni-W interlayer

Adhesion strength and high temperature wear behaviour of ion plating TiN co mposite coating with electric brush plating Ni-W interlayer deposited on a hot work die steel were investigated using a plate-on-ring test rig. The mi crostructure and wear characteristics of the coating were analyzed using XR D, TEM, SEM and EDS. The adhesion of the coating to the substrate was deter mined by scratch test. The results indicated that crystallization and preci pitation-hardening in the electric brush plating Ni-W interlayer and format ion of interface diffusion layer and duplex composite layer at the interfac e occurred due to thermal effects during TiN deposition. The Ni-W interlaye r could provide an effective support for the TiN coating, thus the adhesion strength and hardness of the TIN composite coating increased significantly . In the temperature range 500-700 degreesC, the TiN composite coating with Ni-W interlayer revealed high wear resistance as compared with the single TiN coating. The coefficient of friction and wear rate of the single TIN co ating increased as the temperature increased, while the TiN composite coati ng exhibited the lowest coefficient of friction and wear rate at 600 degree sC. Abrasive and adhesive wear were the predominant wear mechanisms of the coatings at elevated temperatures. (C) 2001 Elsevier Science B.V. All right s reserved.