Preparation And Properties Of Ti₃AlC₂-La₂O₃/Cu Composites

Particle-reinforced copper matrix composite material has good high temperatureproperties,which are widely used in various industries and fields.It has been a focus of thisclass of materials research to improve the comprehensive properties.This paper studied thecopper matrix composites by Ti₃AlC₂and La₂O₃particle cooperation strengthening.In this paper, the Ti₃AlC₂bulk were fabricated by using spark plasma sintering（SPS）method firstly,then Ti₃AlC₂particle which size are less than10m were fabricated byvibrating ball mill and screening technology, and coated particles of Ti₃AlC₂werefabricated by using electroless method. Secondly, different preparation processes ofTi₃AlC₂-La₂O₃/Cu composites were fabricated by hot pressing sintering.The electricalconductivity and mechanical property of the Ti₃AlC₂-La₂O₃/Cu composites were tested,and the microstructures of Ti₃AlC₂-La₂O₃/Cu composites were observed and analyzed byXRD, SEM, OM, TEM and HRTEM, the optimal sintering process which made thecomposites have excellent comprehensive properties was obtained. Finally, different masspercentage Ti₃AlC₂and La₂O₃of composite were fabricated by using the optimal sinteringprocess to further improve the property of the Ti₃AlC₂-La₂O₃/Cu composites.The results showed: the Ti₃AlC₂particle surface were coated with a layer of about0.75m copper after electroless, it was close to the theoretical value0.81m, and thecoating was uniform and no oxidated.The TEM results showed that La₂O₃particles dispersed within Cu grains, and therewas a10¹5nm width inter transition zone between Ti₃AlC₂and Cu matrix, which werehelpful to improve the integrated properties of the composites.In addition, the5wt%Ti₃AlC₂-0.5wt%La₂O₃/Cu composite which was sintered at825℃, held for10min,the Ti₃AlC₂and Cu have no obvious interfacial reaction,it presented excellent integratedproperties, the electrical conductivity was about69%IACS, the tensile strength255MPa.The property of composites are affected by the sintering temperature and holding time,they have excellent mechanical properties when high sintering temperature and longholding time, whereas they have excellent conductive properties. In the end, the conductivity of composites decline with the increasing of Ti₃AlC₂andLa₂O₃particle contents. However, the mechanical properties of composites showed adifferent tendency, the tensile strength of composites gradually increases first and thendecreases with the increasing of Ti₃AlC₂content, the tensile strength reach275MPa andthe conductivity is about79%IACS when the Ti₃AlC₂mass percentage was2%³%.However it gradually increases with the increasing of La₂O₃mass percentage. In addition,the toughness of composites declined with increasing of Ti₃AlC₂and La₂O₃.