Industrial Diamond Association – Finer Points Magazine
An attempt had been made to identify the sources of residual stress in polycrystalline diamond cutters (PDC) by X-ray diffraction (XRD). Residual stress was measured in a finished 16mm PDC insert
The manufacturing team was looking for a way to reduce the time required to make the cutters. The reason for the cutter failures needed to be determined of frequency and manufacturing time were to be reduced.
High pressure/high-temperature sintering of polycrystalline diamond compacts (PDC) is sensitive to impurities in the diamond feedstock, both surface and intrinsic.
Sandia National Laboratories and U S Synthetic Corporation have jointly conducted a multifaceted, baseline experimental study to support the development of improved drag cutters for advanced drill bits.
PDC bits have had limited success at drilling high compressive strength and abrasive rock formations. One of the limitations to hard rock drilling is the propensity of the cutters to fracture.
Residual stresses in PDC cutters arise from the difference in thermal expansion between the polycrystalline diamond layer and the supporting tungsten carbide substrate after sintering at high pressure and temperature. If not managed correctly, these stresses can significantly reduce the toughness of the cutters, especially as the diamond-layer thickness increases.