A COMPARISON OF THE WEAR LIFE OF AS-DEPOSITED AND ION-IRRADIATED WS2 COATINGS

The effects of high energy (MeV) ion-irradiation on the wear life of a morphous sputter-deposited WS2 coatings were studied. The coatings wer e deposited by DC magnetron sputtering on M50 steel and Si3N4 substrat es. The coatings were characterized by transmission electron microscop y (TEM) and Auger electron spectroscopy (AES) for microstructure and c omposition, respectively. Nano-hardness indentation was used to determ ine the hardness of as-deposited and ion-irradiated WS2 coatings. Scra tch tests were performed to determine the coating adhesion with the su bstrate. The wear life was measured in vacuum as well as in 50% relati ve humidity using a pin on disc tribotester. The results indicated the amorphous nature of the coatings both before and after irradiations. Compared to the as-deposited coating, the ion-irradiated WS, coating e xhibited higher hardness and increased adhesion. The wear life of ion- irradiated WS2 coating was significantly improved in both vacuum and h umid environments due to enhanced adhesion and higher hardness. (C) 19 97 Elsevier Science S.A.