Research on polycrystalline diamond compact (PDC) with low residual stress prepared using nickel-based additive

Polycrystalline diamond compact (PDC) with low residual stress was synthesized using nickel-based additive (Ni₇₀Mn₂₅Co₅) as sintering solvent at high temperature/pressure (HTHP). A systematic study of the residual stress in a polycrystalline diamond (PCD) layer was performed using micro-Raman spectroscopy. The stress was measured by determining the Raman shift and was approximated as being biaxial to calculate the magnitudes of stress. Sintering process parameters such as temperature, the diamond size and content of binder additive were all found to affect residual stress levels. The sample with low stress measured on the surface of PCD is compressive and has an average value of 0.10 GPa. Scanning electron microscopy (SEM) analysis of morphology shows that the dense microstructure with diamond-diamond (D-D) direct bonding has formed in the PCD layer. X-ray diffraction (XRD) performed in the cross-section of PCD confirmed the presence of diamond, nickel-based alloy, WC and Co_xW_xC.