| Particle-reinforced copper matrix composites are widely applied in spaceflight,aviation, machinery, electricity, military and so on. Ti2AlN is one of new layered ternaryceramics which has both excellent properties of ceramic materials and metal. Therefore,Ti2AlN is the ideal particle reinforcement in copper alloys.In this paper, Ti2AlN bulk materials were fabricated by spark plasma sintering(SPS).Then the bulk materials were crushed into fine power. The surface of Ti2AlN powder wasmodified by electoless plating method. The Ti2AlN/Cu composites in different masspercentage (3-7%) were fabricated by using SPS. And its density, hardness, strength,electrical conductivity were also tested. The microstructures of Ti2AlN/Cu compositeswere analyzed by OM, XRD, SEM, FE-SEM and TEM. Then the relationship betweencomposites' microstructure and mechanical or physical properties were analyzed, theeffect of surface modification of powder were also discussed. Finally, the tribologyproperties of Ti2AlN/Cu composites in different content of Cu-coated-Ti2AlN particleswere studied.All the experimental results revealed that: After electoless plated of Ti2AlN particles,a nanosized Cu film formed on them and the interface were modified well; while untreatedcomposites had a bad-combined region, even continuous gap formed in the interface. Thedensity, conductivity, hardness and tensile strength of coated or uncoated composites indifferent particle contents shown the same tendency, but at the same contents of particle,all the properties of coated ones were better than them of uncoated. In particular, theconductivity of coated composites gradually decreased with the increase of Ti2AlN content.The conductivity still maintained60%IACS when Ti2AlN particle maximum content wasabout7%. The tensile strength of coated composites gradually increased with the increaseof Ti2AlN content. The tensile strength achieved380MPa (7%Ti2AlN), which was1.6times greater than it in pure copper.The wear mechanism of copper changed from adhesive to abrasive with the additiveamount of Ti2AlN particles, and the wear resistance was improved. The friction coefficient and weight-losing of copper reduced gradually with the increase of Ti2AlN contents. |
