To investigate sliding friction and wear behaviors of WC-Co/WC-Co pairs containing different WC grain sizes, the ball-on-disc test in air were carried out, where WC grain sizes a (F.G.) and (C.G.). The wear volume of F.G. pin for F.G. pin/C.G. disc is larger than that of F.G. pin for F.G. pin/F.G. disc due to higher friction coefficient, and the surfaces after wear test are richer in oxygen compared to those before test. Furthermore, the wear debris, which is composed of nona-scale grain, after the wear test are remarkably richer in oxygen than to those before test.

• Hosokawa
• H.
• Nakajima
• T.
• Shimojima
• K.