Study On Preparation And Microstructure And Properties Of WC/Cu Surface Composites By Stirring Friction

In this paper,T2 copper and WC were selected as the base material and enhancement phase,friction stir processing(FSP)method was used to prepare WC/Cu surface composite,Based on the optimum preparation of FSP on WC,research the effect of particle size and content on the surface layer microstructure and properties,and explore its influence mechanism;at the same time,for the preparation of FSP composite on the surface of practical problems,and put forward a preliminary attempt of friction stir increasing material manufacturing realize WC/Cu surface preparation of composite materials use.Research results show that: under this experimental condition,FSP after three passes can be obtained with good forming by using the needle thread taper stirring head,the mixing head rotation speed n=950r/min,the speed v=23.5 mm/min(n/v value=40.43),and the inclination angle is 2o,it is helpful to reduce the oxidation of surface composite layer,using argon gas protection in the process of FSP and enhance more decentralized WC/Cu surface materials.The content of WC and the particle size of WC have obvious effect on the surface of the composites,with the WC content increase or joining particle size decreases,and the material plasticizing migration is more difficult,broken particles are more likely to be reunited,the particles disperse uniformity is worse,instead particle size in composite layer increases.The structure and performance of the surface composite layer are obviously effected by The original particle size and the addition of WC.In a certain range,WC will be even more homogeneous in the distribution of composite materials as the increase of WC original particle size.With the increase of WC addition,the uniformity of WC distribution in composites is worse.The hardness of composite material increases with the original particle size of WC,and increases with the increase of WC.With the increase of WC content,the average surface hardness of composite layer is increased,when the amount of WC was 15.7vol.%,the average surface hardness of179.86 HV,is about 140% higher than T2 copper;From the distribution of micro hardness,with the increase of WC content,the micro-hardness distribution is more all show that the WC surface composite layer reinforced phase dispersed uniformly withthe increase of WC content decreased.The tensile strength of the composite layer with the amount of WC increases,when the amount of WC was 15.7vol.%,the tensile strength of the composite layer reached 283 MPa,increased by 28.6% compared to not join the FSP specimen of WC;The changing trend and the tensile strength and the elongation of the contrary,decreased with increase of WC added.With the addition of WC,the surface wear resistance of the composite layer can be greatly improved.With the addition of WC,the wear resistance of the surface composite decreases gradually,and the addition of WC has a good lubrication and antifriction effect on the composite layer.The addition of WC reduced the conductivity of the composite layer to some extent.When the amount of WC was 15.7vol.%,the conductivity of the composite layer was 36.45MS/m,which was about 15.86% lower than that of the friction stir processing sample without WC.The composite material was well formed with good forming and clear interface combination can be obtained.when the bearing volume of WC/Cu surface composite was 0.15 mm.