Tribological behavior of cBN-WC-10Co composites for dry reciprocating sliding wear

摘要

This work aims to understand the tribological behavior of cBN-WC-10Co composites subjected to the dry reciprocating sliding wear. The tribological behavior was characterized by the coefficient of friction (CoF) and the specific wear rate. The wear test was designed and performed on the composites against SiC ceramic ball at an ambient temperature, and the SEM morphologies for both of the composites and SiC ceramic ball were measured to reveal their tribological behavior. It was found that the cBN-WC-10Co composites was worn out in two manners, i.e., abrasive wear and oxidation wear, and the abrasive wear was dominant. The cBN particles in the composites were worn out by polishing, fracturing and pulled-out. It was also found that (1) adding cBN particles improved the wear resistance of cBN-WC-10Co composites greatly in comparison with that of the WC-10Co cemented carbides; (2) reducing particle sizes in cBN-WC-10Co composites reduced the specific wear rate when the normal load was below certain value (50 N); while using large particle sizes showed better wear resistance when the normal load was continuously increased. The wear of SiC counter body was much severer when against cBN-WC-10Co composites in comparison with that against WC-10Co cemented carbides. This was due to the fact that the cBN particles in the composites acted as micro cutting edges to wear SiC ceramic.