Effect of Extrusion Temperature on Wear Resistance of Hot-Extruded Cu-17Ni-3Al-X Alloy

The microstructure, mechanical properties and wear resistance of Cu-17Ni-3Al-X alloy extruded at 1 000-1 100 ℃ were investigated by microstructure observation, mechanical property testing, friction and wear property testing. The results show that the wear resistance of the hot-extruded alloy increased significantly compared to that of the as-cast alloy. With the increase of extrusion temperature the wear resistance of the alloy decreased. When the extrusion temperature was 1 000 ℃, the alloy obtained the best wear resistance. The tensile strength and hardness of the alloy decreased generally but the elongation slightly increased when the extrusion temperature increased. Tensile strength of 994 MPa, elongation of 8%, hardness of 292 HBS and matrix micro-hardness of 319 HV were achieved when extrusion temperature was 1 075 ℃, which increased by 31%, 280%, 7% and 11%, respectively, compared with those of the cast alloy. The improvement of the wear resistance of the hot-extruded alloy compared with the cast alloy was mainly attributed to the grain refinement after extruding, which reduced the adhesive wear of the α(Cu) matrix accordingly. Both adhesive wear and abrasive wear were main mechanism in the wear process.