Tribological and fatigue failure properties of porous P/M bearing

The performances of porous bearings under different operating conditions were experimentally investigated in this study. The tribological properties and fatigue failure of porous P/M bearings under dynamic loading were studied. Cu-based bearings were used in the tests at different average bearing values of PV (P is the load pressure on the projected area, V is the surface velocity of the journal). In the experiments, the variation of the coefficient of friction (μ) and wear ratios for different PV values were investigated. As a result, the variations of the averaged friction coefficient – number of cycles, wear loss, cycle curves – were plotted separately. Also, the worn surfaces of test bearings were examined using optical microscopy. The friction coefficients and wear loss ratios in the low PV values are smaller than the higher PV values at test bearings. Fatigue cracks propagation may be facilitated by the pores among powder particles.