Study On Preparation And Arc Erosion Resistance Of Dispersion Strengthened Copper Matrix Composites

The main feature of dispersion strengthened copper matrix composites is thatceramic phase particles with great physical and chemical stability, such as Al₂O₃, CrO₂,TiB₂, SiC, etc., are dispersed in the copper matrix uniformly and finely. Theconductivity and strength of dispersion strengthened copper matrix composites are notonly good at room temperature, but also at a high temperature. Dispersionstrengthened copper matrix composites have potential applications in electrical contactareas, such as high-speed railway catenary systems, high pressure switch contact,microelectronics and electrical control. Fabrication methods, content or size of thedispersion particle are key factors affecting the performance and arc erosion resistanceof dispersion strengthened copper matrix composites.Al₂O₃/Cu composites were respectively fabricated by internal oxidation, coldsintering and SPS in this paper. The effects of different fabricated methods onproperties of Al₂O₃/Cu composites, such as density, hardness and electricalconductivity, were studied. With TiB₂/Cu composites as studying objects, the effects ofTiB₂content on arc erosion resistance of TiB₂/Cu composites were studied. WithAl₂O₃/Cu composites as studying objects, the effects of Al₂O₃size on arc erosionresistance of Al₂O₃/Cu composites were studied.The results showed that:1. The Al₂O₃particles in the Al₂O₃/Cu composites fabricated by internaloxidation were uniformly dispersed in the coppor matrix in fine grain. Thecomprehensive properties of the Al₂O₃/Cu composites fabricated by internal oxidationwere better than. cold sintering and SPS. Agglomeration of Al₂O₃nanoparticlesemerged in the Al₂O₃/Cu composites fabricated by cold sintering as well as SPSmethod, which affected the comprehensive properties of the Al₂O₃/Cu composites. Thedensity and electrical conductivity of the Al₂O₃/Cu composites fabricated by coldsintering were lower than internal oxidation and SPS. The density and electrical conductivity of the Al₂O₃/Cu composites fabricated by SPS were higher than internaloxidation and cold sintering, which reached99.18%and96%IACS respectively. Butdue to the lack of subsequent processing, the hardness was relatively lower. TheAl₂O₃/Cu composites fabricated by cold sintering were relatively denser with smallergrains.2. In the experimental range, the density and conductivity of the TiB₂/Cucomposites were gradually reduced with the TiB₂content increasing, and the hardnesswas increased at first and then decreased subsequently, which due to agglomeration ofTiB₂nanoparticles in TiB₂/Cu composites with TiB₂content increasing. The hardnessand electrical conductivity respectively reached75.9HBS and86.3%IACS when theTiB₂content of the TiB₂/Cu composites reached3.0vol.%. Arc energy of the TiB₂/Cucomposites was increased with the TiB₂content increasing. The microstructureobservation showed that the arc erosion melting degree on composites surface wasreduced and the overall erosion area was decreased with the TiB₂content increasing.And arc erosion resistance of the TiB₂/Cu composites was enhanced with TiB₂contentincreasing.3. Arc erosion resistance of Al₂O₃/Cu composites did not show a certain trendwith Al₂O₃particles size increasing. The surface of Al₂O₃/Cu composites with Al₂O₃particle size of100nm was relatively flat, which showed good arc erosion resistanceand had the lowest arc energy.