Homogeneous and structured PCD/WC-Co materials for drilling

Traditional polycrystalline diamond (PCD) materials for the rock-boring industry have been primarily composed of diamond particulates with a small volume fraction of cobalt as a binder/catalyst. Although these materials provide a cost-effective solution in many drilling applications, the catastrophic nature of the failure modes seen with these materials is a limiting factor in the increased usage of PCD in rock drilling. Research performed at Smith International has shown that composite PCD materials incorporating WC-Co as a third constituent have marked improvement in delaying the onset of catastrophic failure. These composite materials can be separated into two classes: (a) "homogeneous" composites and (b) "structured" composites. This paper reviews microstructures, material properties, field performance, and failure modes observed with these two new types of PCD composite materials. (C) 2004 Elsevier B.V. All rights reserved.