Research on organization and performance of Mo reinforced copper matrix nanocomposites prepared by Thermite reaction

摘要

Using thermite reaction-self-propagating sintering prepare reinforced copper matrix composite materials in which percentage of Mo are 5％, 10％ and 20％ respectively.The phase and microstructure morphology of the composite material are analized by the use of X-ray diffraction, transmission electron microscope, scanning electron microscopy (SEM)and metallo graphic microscope and studied the influence of molybdenum content on the mechanical properties of composite materials, conductive performance, the influence of the thermal expansion coefficient.Results show that the composite matrix grain size could be in nano-scale and the density reaches above 90％, the hardness is increased by more than 40％ compared with pure copper, conductive good performance (more than 72％ IACS)with this procedure.With the increase of molybdenum mass fraction, the hardness of the composite increased, density, conductivity and thermal expansion coefficient decreased.When Mo is the mass fraction of 20％ thermite reaction, density of composite material achieves 91.88％,the conductivity of which could reach 72％ IACS, twice times the hardness of pure copper, 13％ lower coefficient of thermal expansion than pure copper and comprehensive performance achieves optimum.The main mechanism of composite material hardening dislocation caused by the reverse domain by orderly strengthening phase molybdenum orderly hardening, and hardening modulus of the strengthening phase of molybdenum and copper base elastic modulus difference caused by two kinds of combined hardening model.