Abstract
In this study, minor-addition elements such as Si, Co, Cr, W, Mo and Ti were added into matrix to improve the wettability between the diamonds and Cu matrix. The pressureless liquid phase sintering technique adopted in this study provides a low-cost method for producing diamond/Cu composites with high potential for industrial mass-production. Thermal properties of the diamond/Cu-Ti composites fabricated by pressureless liquid phase sintering at 1373 K with variations in Ti contents and in sintering times were thoroughly investigated. SEM and TEM analyses were utilized to study the growth mechanism of the TiC at the interface between diamonds and Cu matrix. A probable mechanism of the interface structure formation was proposed. The composites exhibited thermal conductivity as high as 620 W/m•K for 50 vol% diamond/Cu-0.6 at% Ti composite with diamond particle size of 300 µm. This value comes up to 85% of the thermal conductivity calculated by Hasselman and Johnson (H-J) theoretical analysis. Under these conditions a suitable coefficient of thermal expansion of 6.9 ppm/K was obtained.