Abrasive Wear Resistance of Powder Composites at Abrasive Erosion and Abrasive Impact Wear

Composite materials produced by powder metallurgy provide solution to many engineering applications where materials with high abrasive wear resistance are required. The actual wear behaviour of the material is associated with many external factors (the abrasive particle size, velocity and angularity) and the intrinsic material properties of wear (hardness, toughness, Young modulus, etc.). The hardness and toughness properties of wear resistant materials are highly dependent on the content of the reinforcing phase, its size and on the mechanical properties of the constituent phase. This study makes an attempt to model abrasive wear (solid particle erosion and impact wear) by using the centrifugal erosive and impact wear devices. Powder materials (cermets, metal-matrix composites and powder HSS) were under the study. The abrasive wear resistance at solid particle erosion (AEW) and the impact wear (AIW) of materials were researched and the mechanisms of surface degradation were studied and compared with the wear mechanisms of commercial steels. Different abrasive materials (quartzite and granite) with the average particle size of 5.6 mm and 0.1 mm - 0.6 mm were under the study. The behaviour patterns of powder composite materials at AEW and AIW were compared. Based on the research into abrasive wear resistance, the wear maps, such as wear resistance versus hardness and toughness of materials, were compiled. According to the study of wear mechanisms, a wear map proceeding from toughness and hardness was created. The following parameters were found necessary for materials selection: hardness (preferably dynamic) characterizing the material removed at plastic deformation, fracture toughness characterizing the brittle fracture mechanism and the fracture probability.