Research Of C_sf/Cu Composite Prepared By Powder Metallurgy And Its Properties

Cf/Cu composite with copper's high electrical-conductivity, high thermal-conductivity, carbon fibers'low coefficient of expansion, and favorable lubricity is applied broadly, which is used by electricity and friction. The powder metallurgy having good molding and batch production etc is attended. The problem of techniques about manufacturing Cf/Cu composite material in documents is further studied.This paper has advanced new techniques of carbon fibers roughening, applied heat treatment of muffle furnace and nitric 20% acid to surface of carbon fibers, applied dispersing agents and ultrasonic technology to disperse the fiber bundle, studied three complexing agents(EDTA2Na, C4O6H2KNa, C3H8O3) to the quality of copper-coats. Studied the EDTA2Na, NaOH, and CH2O ect to the effect of copper plating by using Orthogonal Experiment Method. Analyzed the surface of carbon fibers and quality of copper-coats by SEM. The results are shown that: the short carbon fibers treated by ignited in muffle furnace at 200℃high temperature during 40min are more rough by nitric acid, and hydrophobicity is improved;The best formula of plating solution was determined by CuSO4 16g/L, CH2O 14ml/L, NaOH 18g/L, Na2EDTA 30g/L, (C5H4N)2 6mg/L, K4[Fe(CN)6]·3H2O 20mg/L. Copper coating deposited on carbon fiber was bright, uniform, dense and without black core, the thickness is more than 1.5μm.The paper adopts copper facing carbon fibers and copper powder to obtain Cf/Cu composite material by powder metallurgy, use 200MPa pressing, sinter at 850℃in N2 atmosphere and keep 2 hours. Abtain 5%,10%,15%,20%,25% different volume Cf/Cu composite material. The results are shown that: Csf/Cu composite have relative density, Carbon fibers uniformly disperse in matrix. Relative density with the increase of fibers volume fraction decreases slowly, when more than 15 percent fibers volume, the relative density with the increase of fibers volume fraction decreases rapidly, the relative density of 25vol%Csf/Cu composite is 91.2%;Carbon fibers significantly improved the physical and mechanical properties of copper. With the carbon fiber volume fraction increase, the wear resistance of composite materials monotonous increase , density and conductivity of monotonous decrease, the first the hardness increases and then decreases. In comparison, the fiber volume fraction of 15%Csf/Cu composite has the best overall performance;The fiber volume fraction of 15% Csf/Cu composite has short fibers pull-out from fracture, reveals the moderate interfacial bonding strength.