Study On Preparation By Powder Metallurgy Method And Properties Of Cu/TiB₂Composite

Owing to its advantage of high strength, high electrical and thermal conductivity, high hardness, good wear resistance, copper matrix composites is widely applied in the area of contact material, welding electrode, integrated circuit frame, etc. Because the TiB2has a lot of excellent characteristics such as high strength, high hardness, good resistance to abrasion and low coefficient of thermal expansion, good electrical and thermal conductivity, so it is a good reinforcement for composite materials. Therefore, the Cu/TiB2composites attract the researchers’attention in the composite material area.In this paper, by using the powder metallurgy method, taking the Cu powder, Ti powder, LaB6powder as raw material, TiB2particles were fabricated by in situ reaction in copper matrix composites. The planetary ball milling mixing and high-energy ball milling were both used to prepared the composite powder, by testing the particles’diameter using laser particle size analysis and XRD results analysis, to find the best way of the ball milling, and the milling time.According the results, adjust the process parameters to find out these parameters’ influence to particle diameter and powder efficiency; In the process of hot pressing sintering, Prepare the Cu/TiB2composite materials under different process conditions, and analyze the results, by using the metallographic optical microscope, scanning electron microscope (SEM), X-ray diffraction (XRD) and energy spectrum (EDS) to analyze the composite material, the microstructure of the composites were also analyzed, and tested the physical and mechanical properties of composite materials, including density, microhardness and tensile strengthconductivity of composite material after hot rolling, studied different sintering process parameters and different reinforced materials’content of Cu/TiB2composite materials’ performance; The results show:(1) Different ball milling equipment mainly influenced the composite powder’s powder efficiency, when the milling time is20h, the planetary ball milling’s powder efficiency is7%higher than high-energy ball milling, so in this research, choose the planetary ball milling for mixing the powder;(2) Cu-Ti-LaB6mixed powder particle size decreased and theXRD are weakened with the extension of mill time.In the initial stage, particle size decreased quickly, when the milling time is more than20h, particle size decreased slowly and tends to a stable value. Considering both the efficiency of ball milling and particle size, ball milling time20h is good;(3) Using the powder metallurgy method, the sintering temperature is950℃, sintering time for2h, the theoretical content of TiB2was5%wt by in situ action prepared the Cu/TiB2composite materials, electrical conductivity was87%IACS, microhardness reached115HV, and the tensile strength reached410MPa;(4) Within a certain range, higher sintering temperature and longer sintering time can improve the materials’ density and electrical conductivity, tensile strength and microhardness increased with the increase of the temperature and time; With the increase of TiB2content, the strength, electrical conductivity of the composite materials decreased, and the microhardness increased; According to the experimental results, we concluded that the reasonable preparation parameters:in the sintering process, the pressure of50MPa, the sintering temperature is950℃, sintering time for2h, the content of reinforced material was5%wt, then we could prepare composite materials with good properties.