Effect of Cobalt on PCD Fracture Toughness: J. Daniel Belnap, Ph.D. Smith Megadiamond

摘要

Polycrystalline diamond (PCD) is commonly used in applications requiring high abrasion resistance such as oil and gas drilling and industrial cutting tools. Besides inherently high abrasion resistance, respectable mechanical properties (flexural strength and fracture toughness) also contribute to the expanding use of PCD materials in applications worldwide. The study determined the measured effect that cobalt has on fracture toughness of PCD compacts by experiments on samples containing cobalt and samples in which the cobalt has been removed by a chemical leaching process. The test method used to measure fracture toughness was diametral compression of through-slotted PCD disks. In addition to the fracture toughness test results, observations on fracture surfaces and measurement of compressive residual stresses in the PCD materials were performed and the results discussed.