Copper infiltration process of porous diamond preforms

Diamond/copper composites have good thermal-physical properties and could be net-shape formed by infiltration.In the present paper,relevant process and influencing factors of porous diamond preforms infiltrated by copper were studied.The results show that it is helpful to infiltration of copper into diamond preforms when the copper are placed on both the top and the bottom of the preform.The density of the composites can reach 99.8% which is near full density,and the thermal conductivity can reach 587 W/m.K,when the infiltration is carried out at 1 200 ℃ with 20 MPa and hold for 30 min,however there is no obvious change for the density by further incerasing the infiltration temperature and holding time,and the thermal conductivity may decrease.This is associated with the increase of interfacial thermal resistance due to the change of interface structure.There is an incubation period during the pressure infiltration process,that is the density may decrease and the infiltration even can not be completed when infiltration temperature is below 1 200 ℃ or pressure is less than 20 MPa.