Abstract:Axial piston pumps are the key parts of the hydraulic system. The life and reliability of the plateinclined axial piston pumps are directly determined by the materials, their match and selection of technical parameters of the three friction pairs, including the inclined plateslipper pairs, the cylinderpiston pairs and the cylindervalve plate pairs. The wear condition of the friction pairs composed by the hard materials (38CrMoAl, 20CrMnTi, 30CrMoVA) and the soft materials (HMn583, QAl94, QT5007) were recorded by experiments using the MWF10 reciprocating type friction and wear test machine. Based on the analysis of Taguchi method, the influence of the surface roughness and hardness of the matching materials to the frictional coefficient and wear loss was obtained. The minimum wear loss appears when the friction pair materials are soft of HMn583(Ra02)/20CrMnTi (Ra02). The surface roughness of the hard material influences most to the wear loss and frictional coefficient.