Effect on the Wear Resistance of Copper Alloy Surface Modification Layer by FSSP Implanting W Particles

Abstract

This paper aims to study the surface modification of H62 copper alloy with W nanoparticles implanted on its surface by friction stir surface processing (FSSP). Three implantation methods were studied, with the total implantation depth of 0.2 mm in each method. The first process method is that W powder is extruded to the surface of the copper alloy at a depth of 0.2 mm directly and one-timely through the tool. The second process method is to extrude the W powder into the surface of the copper alloy at a depth of 0.15 mm by a tool firstly, then return the tool to the starting end, and rotate the tool again on the copper alloy surface at a depth of 0.05 mm. The third process method is also to extrude the W powder into the surface of the copper alloy at a depth of 0.15 mm by a tool firstly, then move the tool backward from the stirring end to the starting end on the copper alloy surface at a depth of 0.05 mm. The microstructure, hardness and wear properties of the modified layers of the samples obtained from the three FSSP modified copper alloy surface techniques were tested and analyzed. The results of the three process methods show that W particles can be used to modify the surface properties of copper alloys, but the second process method has the best effect. The second process method can well achieve the uniform distribution of W particles on the copper alloy surface. The hardness of the modified layer was improved compared with the base metal. Among them, the hardness of the modified layer obtained by the second process was increased by 41.4%, the third process method was increased by 35.1%, and the first process method was increased by 16.1%. The friction coefficient of the modified layer obtained by the three technological methods is smaller than that of the base metal, and the second method produces the smallest friction coefficient.