Impact Failure of Polycrystalline Diamond Cutters

Abstract

Polycrystalline Diamond (PCD) Cutters are ultra-hard tools used for oil and gas drilling. These tools can fail in the form of spalling due to impact. In this paper, direct impact and quasi-static loading are used to investigate the failure force for leached PCD cutters when loaded at an angle on the edge of their chamfer with a PCD striker or platen. Impact experiments were performed using an impedance match system which ensures the sample is only loaded once; this allows subsequent analysis of the failure surfaces. The failure force at high deformation rate is around 8 kN and at low deformation rate 6.3−+2.3 kN. The failure force required for spalling increases with increasing deformation rate. High speed imaging is also used to explore the failure history of the cutters.