Fabrication and characteristics of sintered copper-silica composites

Abstract

The paper presents the results of research on the production of a sintered Cu-SiO2 composites fabricated by powder metallurgy. The starting materials for obtaining the composites were commercial powders: Cu and SiO2. SiO2 particles were introduced into a copper matrix in the amount of 2.5 %, 5 %, 7.5 % and 10 % by weight. Finished powders mixtures were subjected to single pressing with a hydraulic press at a compaction pressure of 620 MPa and then subjected to sintering process at 900 °C in an atmosphere of dissociated ammonia. The sintering time was 60 minutes. The sintered compacts were subjected to the following tests: hardness, measurement of density, electrical conductivity and abrasion resistance. The highest density was obtained for a composite containing 2.5 % SiO2 which was 7.94 g/cm3. The highest hardness was obtained for a composite containing 10 % SiO2 which amounted to 50 HB. For the composite containing 2.5 % SiO2 the highest electrical conductivity was obtained which was 47 MS/m. The highest abrasive wear resistance was obtained for a composite containing 10 % SiO2. Both density and electrical conductivity decreased along with the increase of SiO2 content in composites.