Nano Carbon (Tungsten) Copper Composite Powder Prepared By Spray Drying Method And Its Composite Materials Research

High performance copper matrix composites have been widely used in electrical engineering, military industry, mechanical manufacture and so on, they not only have excellent electrical and thermal conductivity, and have high hardness and strength, at the same time also have good electric erosion resistance. In this article, four copper composite powders were produced by spraying drying-calcination-reduction method, and then its composites were prepared by different forming methods. The influencing factors and the reliable parameters of preparation of copper matrix composites were dicussed through the characterization of composites microstructure, powders composition and the tests of microhardness, electrical conductivity, relative density of those compsoites.(1) High-copper ratio W/Cu compsites(15WCu and 20WCu) were prepared by mould pressing(MP), spark plasma sintering(SPS) and cold isostatic pressing(CIP). The results show that, 1130℃ is the best sintering temperature for 15 WCu and 20 WCu prepared by MP; The 15 WCu and 20 WCu prepared by SPS have best performance in sintering at 700℃,10 mins and 15 mins,respectively; Comparing three methods, the SPS sample equally matched with CIP sample in the performance, and MP sample is next. Compareing two composites, 15 WCu is better than 20 WCu. 15 WCu sample have an higher electrical conductivity and an more compact copper network, because it own a higher copper content than 20 WCu. While 20 WCu have a higher tungsten content, the tungsten particles were agglomerated at sintering process, so the relative density and hardness of composite are decline.(2) CNTs/Cu composites were fabricated by MP and CIP. The results show that, along with the increase of the content of CNTs in CNTs/Cu composites, the microhardness have greatly improved, and the electrical conductivity and density were decreased, but not obvious, and the optimum point of comprehensive performance at 0.5wt%; Compareing two composites, the results indicated that the cold isostatic pressing method is superior than the mould pressing method; The thermal conductivity test of 0.5wt% composites show that the 0.5wt% CNTs composite formed by cold isostatic pressing have an high electrical conductivity up to 87.26%IACS, whose microhardness and thermal conductivity increased to 105.24 HV and 407.84W/(m K).(3) RGO/Cu composites were prepared by MP and SPS, RGO/W/Cu composites were prepared by SPS. It turned out that, RGO uniformly distributed in dendritic copper particles, the good combination of RGO and copper powders have be found. And Cu2 O in composite powders was detected by X-ray diffraction, It proves that the reduced ultrafine copper powders have been oxidized by RGO. Compareing two RGO/Cu composites, the SPS samples are near full density and have smaller grains than the MP samples, it proves that the spark plasma sintering is superior than the mould pressing method. The 3wt% RGO/Cu composite have better performance compared with other content composites, especially the 3wt% RGO/Cu composite prepared by SPS have a high microhardness value up to 164.45 HV, increased by 32.36% and have an electrical conductivity as high as 87.51% IACS. The tungsten content is 1.0wt% of RGO/W/Cu composites have optimal comprehensive performance.