Impregnated diamond drill bit construction

摘要

An impregnated diamond drill bit having a generally cylindrical, hollow crown structure with a lower portion containing diamond particles and a steel shank attached to the crown structure at its upper end. The diamond particles are dispersed within a metal matrix in the lower portion of the crown. Around both the outside circumferential wall and the inside circumferential wall of portions of the crown structure, there are layers of a highly wear resistant material. These layers are formed of a material that is more wear resistant than the material used for the metal matrix in which the diamond particles are dispersed.