Tribological Behavior of Polycrystalline Cubic Boron Nitride Sliding against WC-Co Cemented Carbide in Vacuum Conditions.

Tribological properties are the significant factors to evaluate the application of polycrystalline cubic boron nitride(PcBN) with hard materials in vacuum conditions. In the current paper, the tribological properties of PcBN and WC-Co cemented carbide (YG8) during the sliding process are carried out under different loads in vacuum by ball-disk friction and wear experiments. The wear tracks of PcBN and wear scars of YG8 were characterized. The results show that the wear mechanisms of PcBN in vacuum are mainly abrasive wear and adhesive wear. Furthermore, furrows are also detected on the surface of YG8 balls due to the plowing of exfoliated cubic boron nitride. As a result, abrasive wear is the failure form of YG8 ball. The average CoF is negatively correlated with the loads. Moreover, the relationship between friction and wear is discussed deeply. The wear rate of YG8 ball is positively correlated with the load. Additionally, the wear rate ratio of PcBN and YG8 indicates that higher loads can promote the wear rate of YG8, but it also leads to the rapid wear of PcBN. The results could provide significant instructions for the regulation and control of the tribological properties of PcBN in the coming outer space exploration activities. [ABSTRACT FROM AUTHOR]