Study On Microstructure And Thermal Physical Properties Of β-Eucrypitet/Cu Composites

β-Eucryptite(Euc) particles reinforced copper matrix composites, with the different volume fraction , were fabricated by vacuum heating-press sintering. The micro-structure of Euc/Cu composites was studied by optical microscope, scanning electron microscope and transmission electron microscope. The compactness of Euc/Cu composites was analyzed by means of analytical balance. The thermal physical properties of Euc/Cu composites were analyzed by means of thermal dilatometer, thermal conductivity tester, also with their influencing factors discussed.Analyses indicate that there is not interfacial reaction at Euc/copper interface. After the composites were annealed 4 hour at 1000℃, the surfaced Euc of the composites was disappear.In the macroscopic state, the dispersed Euc in the copper matrix is uniformity. In the microscopic state, there was the aggregation phenomenon of Euc particles in the composites. With the volume of Euc increasing, the aggregation phenomenon of Euc particles in the composites was more evidently. There are obverse holes around the Euc particles.With the Euc volume increasing, the densification of the composites is decreasing. When the volume fraction increased to 50%, the densification of the composites decreased to 89%.With the Euc volume increasing, the average coefficient of thermal expansion of the composites is decreasing. When the volume fraction increased to 50%, the CTE of the composites decreased to 10.5×10^-6℃^-1.The studies of thermal expansion behaviors of the composites show that the residual stress relaxation affects greatly the coefficient of thermal expansion of the composite.The annealing process can decrease the coefficient of thermal expansion of composite, the main reason is that the vacuum anneal can change the stress state and improve the interface binding strength.The thermal conductivity of the composite decreased with the volume of the Euc increasing .The thermal extrusion can make the composites so dense that the thermal conductivity of composites decreased.