The wear behavior of aged Cu-Cr-Zr alloys dry sliding against a brass counterface were investigated on a pin-on-disk wear tester under electric current conditions. The worn surfaces of the aged Cu-Cr-Zr alloys were analyzed by scanning electron microscope (SEM) and energy dispersive X-ray spectrum (EDS). The results indicated that the aging treatments had an effect on the microstructure, hardness and wear resistance of Cu-Cr-Zr alloy. At the constant current density, the wear rate of Cu-Cr-Zr alloy decreased with aging temperature, and reached the minimum at 500℃, then increased with further increasing aging temperature. An appropriate aging treatment may improve the wear resistance of the materials due to the formation of fine, dispersive and coherent precipitates within the matrix. An increase in electrical current resulted in an increase in wear rate of both the Cu-Cr-Zr alloy pin, and the brass disk. Adhesive wear, abrasive wear and arc erosion were the dominant mechanisms during the electrical sliding processes. Compared with commercially used Cu-Ag alloy wire (CTHA110) under the same test conditions, the Cu-Cr-Zr alloy treated at 500℃ for 2 h exhibited much better wear resistance.

Adhesion strength and high temperature wear behaviour of ion plating TiN composite 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 microstructure and wear characteristics of the coating were analyzed using XRD, TEM, SEM and EDS. The adhesion of the coating to the substrate was determined by scratch test. The results indicated that crystallization and precipitation-hardening in the electric brush plating Ni-W interlayer and formation of interface diffusion layer and duplex composite layer at the interface occurred due to thermal effects during TiN deposition. The Ni-W interlayer 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 500-7008C, 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 coating increased as the temperature increased, while the TiN composite coating exhibited the lowest coefficient of friction and wear rate at 6008C. Abrasive and adhesive wear were the predominant wear mechanisms of the coatings at elevated temperatures.