| The copper matrix composite reinforced by in-situ nano-TiB2 was prepared by electromagnetism sintering and hot pressing of boron (B), titanium (Ti) and copper (Cu) powders, which were evenly mixed and then cold molding by press machine. The microstructures and phase composition of TiBB2/Cu compositeswere studied with SEM, XRD. The formation mechanism of TiB2B in Ti-B-Cusystem also was studied by quenching and differential scanning calorimetry .The mechanical properties and conductive properties of composites were tested with hardness-testing device, strength test and conductivity measuration. Thermodynamics calculation and differential scanning calorimetry indicate that Cu3Ti and TiB2 are successively produced in the Ti-B-Cu system.The formation of TiBB2 depends mainly on the diffusion and chemical reaction of the B rich phase arising from the formation of Cu3Ti and the Ti rich phase due to melting of Cu3Ti.Through controlling composition of the composites, we can get pure reaction product TiB2B. In Ti-B-Cu system, the temperature of synthesis of TiB2 is about 1048℃whatever the content of copper. Experimental results show that the synthesis system is affected by the electromagnetic and thermal fields. Then the rate of heat accumulation in reaction zone was faster and the reaction was easier. TiBB2 reinforcement particleswith fine grain, dispersed distribution and good conductibility are fabricated by combustion synthesis within copper matrix. The sizes of the reinforcement particles are nearly 50-300nm. The TiBB2/Cu composite fabricated by this technics has excellent mechanical properties and conductibility. The hardness, conductivity and strength of 3.5wt.%TiB2 reinforced copper matrix composite are 127.6HV, 74.5%IACS and 574.8MPa.
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