Relationship between sintering pressure and leach rate of polycrystalline diamond compacts (PDCs) using central composite design (CCD) modelling

Abstract

The effect of sintering pressure on the microstructure, wear resistance and leachability of polycrystalline diamond (PDC) was studied using central composite design (CCD) modelling. Pressure and leachability had an inverse relationship due to reduced cobalt pool size and increased diamond contiguity with higher pressures. X-ray diffraction and X-ray fluorescence confirmed the selective removal of cobalt during leaching. The relationship between pressure and leachability was modelled as linear: Y = −1.047× + 11.139, valid within the 5–7 GPa pressure range. For a fixed temperature of 1600 °C, the optimum leach rate was 6.1 μm/h at 5 GPa. This study provided insights into optimizing PDC design and leaching processes for improved performance. • Increased sintering pressure results in a reduction in cobalt pool size and an increase in diamond contiguity. • There is an inverse relationship between pressure and leachability. • The relationship between pressure and leachability can be represented by a linear model. • The study confirms that cobalt is selectively removed during the leaching process. • There is a trade-off between wear resistance and leaching efficiency in PDC manufacturing.