| ABSTRACT:The effects of interfacial characterization on the tribological properties, friction surface and sub-surface of powder metallurgy friction materials have been investigated. In detail, the features of interface between matrix and three different friction components (SiC, SiO2and high carbon chromite(HCC)), the relationship between interface features and the tribological performances, and the effects of the proportion of different friction components on the friction and wear properties have been analyzed, respectively. The conclusion can be drawn as the following:(1) Different interfaces are formed between different friction components and the matrix, such as the mechanical bonding interface between SiO2and the matrix, the mechanical-reaction bonding interface between SiC and the matrix, the mechanical-diffuse bonding interface between high carbon chromite and the matrix.(2) Materials containing SiC and high carbon chromite are prone to delamination. While materials containing SiO2are prone to ploughing wear and adhesive wear.(3) Materials containing SiC and high carbon chromite can easily form the mechanical mixing layers (MML) which can reduce the friction coefficient and linear wear. While materials containg SiO2present high friction coefficient and linear wear due to SiO2hinders the formation of MML.(4) When the volume content of friction components is16%, with the content of SiC and high carbon chromite increasing, the severe delamination was considered as the dominant wear mechanism, however, raising the SiO2content, the wear mechanism changed from delamination wear to severe ploughing wear.(5) When the volume content of friction components is16%, delamination promotes the formation of MML, decrease the values of friction coefficient and linear wear, whereas the ploughing behaviors can enhance the values of friction coefficient and linear wear for destroying the PDL and MML. |
PDF Full Text Request