Injection Is Deposited Oxide Particle Reinforced Preparation And Organization Properties Of Copper Composite

Particle reinforced dispersion strengthened copper material is a kind of composites material using metal as the matrix and strengthened by metal oxide, intermetallic compounds or nonmetallic fibers. The main strengthening phases include Al2O3, Y2O3, S;O2, TiC, SiC, TiN, Si3N4etc. Dispersion strengthened copper is the key materials used to make electrodes, contacts, leads, microwave tubes and rectified rotor etc, and has been widely applied in electricity, electrical, electronic and electromechanical industry. The main preparation methods at home and abroad for Cu-Al2O3material include mechanical alloying method and power internal oxidation method. The former method is hard to process and has bad mechanical and electrical properties due to the large Al2O3particles and their poor wet ability with copper matrix. The latter method has unstable physical, mechanical and electrical properties due to their complex preparation process, uncontrollable shape and size of the Al2O3particles and low density. Therefore, using above methods cannot solve the problems that Al2O3has poor wet ability with copper matrix, large particles and with nonuniform distribution. Consequently, it influences the yield and comprehensive properties of dispersion strengthening copper and limits its application range.To improve the wet ability of Al2O3with copper matrix, the particle size and distribution of Al2O3in copper matrix and improve the physical, mechanical and electrical properties of materials, in this paper, we present:(1) Using innovation technology roadmap include spray deposition, internal oxidation, rolling, drawing and so on, as well as adding trace rare earth elements in Cu-Al alloy to prepare CuAl2O3、 CuAl2O3La2O3Y2O3composites materials.(2) Through studying the relevance law of process conditions, physical-chemical deposition environment, and microstructure, physical, mechanical and electrical properties of alloy ingots obtained the optimum process parameter to prepare small axis crystalline grain, no segregation, high density, and small dispersion distribution oxide particles cylindrical shape alloy ingots (melting temperature is1300℃, atomization gas pressure is1.5MPa, beginning deposition distance is350mm and deposition device speed is180deg/s). It results that ingot relative density is94%, deposition efficiency is87%and well near net shape. Through the theoretical research of spray deposition, nucleation of atomized droplets and microstructure formation process of ingot, we established microstructure grains distribution model for the spray deposition alloys ingot.(3) Internal oxidation mechanism and its control is one of the core and key technologies to prepare high performance CuAl2O3CuAl2O3La2O3Y2O3composites materials. In this paper, we studied the thermodynamics and kinetics conditions of internal oxidation. Using the DSC analysis ensure the demanding temperature and time within oxidation process, studying the impact of different reaction temperature and time on microstructure and performance of material; using XRD, SEM and HRTEM to analysis lattice constants, composites microstructure changes and the second phase precipitation particles before and after of internal oxidation, the results show that Al2O3、La2O3、Y2O3particles are small, uniform and no segregation internal oxidation, dispersive distribution in the grain and grain boundary of copper substrate. The wet ability is well and the interface is clean. Crystal structure of Al2O3internal oxidation belongs to the hexagonal system, and the misfit ratio for Cu (f=74%)>25%, non-coherent lattice relationship. La2O3belongs to the cubic crystal structure, and the misfit ratio for Cu (f=22%)5%<f=22%<25%, semi-coherent lattice relationship; Y2O3belongs to the cubic crystal structure, and the misfit ratio for Cu (f=3%)<5%, coherent lattice relationship.(4) Through theory research of experiment analysis and precipitation amount of aluminum, diffusion coefficient of aluminum in copper and the oxides generated nucleation and grain growth, we obtained formation of the second phase oxides particles by diffusion control of parabola growth mechanism, in early of internal oxidation (or low temperature conditions), the formation of Al2O3particles was controlled by diffusion rate of Al atom in grain boundary of copper substrate, in late of the internal oxidation (or high temperature conditions), the formation of Al2O3particles was controlled by diffusion rate of Al atom in grain of copper substrate. Through calculation, we obtained the change law of equilibrium solubility of Al in Cu in Cu-Al alloy, precipitates quantity of Al in supersaturated solid solution under different temperature conditions, as well as particles size of Al2O3is between0.45-24.51μm at different reaction stage, which was basically identical with the experiment results of0.5-20μm the oxides particles that CuA10.55alloys at980℃and after2.5h of internal oxidation.In this paper, the influence of different deformation10%,30%,50%,70%,90%on electrical conductivity, hardness, tensile strength and microstructure of CuAl2O3CuAl2O3La2O3Y2O3material have been studied. Meanwhile, we studied the influence of electrical conductivity, hardness and microstructure of material different annealing temperature at700℃,900℃and980℃. Theoretical analysis of strengthening mechanism, the resistance composition, fracture morphology and fracture mechanism were all discussed. The results show that the density of prepared CuAl2O3materials is higher than8.7g/cm3, the tensile strength is more than450MPa, electrical conductivity is greater than47S/m (conductivity>80%IACS). The density of prepared CuAl2O3La2O3Y2O3materials is higher than8.7g/cm3, the tensile strength is more than500MPa, electrical conductivity is greater than48S/m (conductivity>80%IACS). The mechanical properties and electrical conductivity are better than Cu-1.2Al2O3material prepared by mechanical alloying method and powder internal oxidation method. It has the characteristics of high-strength and high-conductivity alloys. The results shows that, through adding a second-phase reactive elements such as Al, La, Y, combined with internal oxidation generates oxide particles, it not only improve wetting and binding properties of the interface, but also has a effect of synergistic enhancement. The materials performance has been improved significantly compared with conventional single enhancement phase.Electric contact material has the arc erosion and metal transfer in actual conditions. In this paper, we researched material transfer of CuAl2O3and CuAl2O3La2O3Y2O3material in DC resistance load conditions (20V,20A, contact pressure is60N, opening and closing contact work is10,000times) according to the arc erosion theory of contact material. The surface morphology features of rivet contact material by arc erosion, metal transfer and arc erosion mechanism have also been studied. We obtained the physical model of arc erosion processes and the energy transfer formulas. Meanwhile, we obtained the law of CUAI2O3、 CuAl2O3La2O3Y2O3material transferred from the anode to the cathode under arc erosion effect, arc erosion morphology composed by starchiness, skeleton and void appearance, arc erosion resistance properties of multiphase oxide particle-reinforced copper matrix composites, which is better than single oxide particle reinforced materials.