Attachment geometry for non-planar drill inserts

摘要

A manufacturing method and a drill bit composite insert for performing mechanical actions that require high wear and impact resistance are provided. The composite insert has improved interface strength and improved residual stress distribution. These improved features are achieved by chemically and mechanically attaching the layer of abrasion and corrosion resistant polycrystalline material to the substrate that ordinarily is tungsten carbide. The chemical bond is formed during high pressure and high temperature sintering. Mechanically, the abrasion and corrosion resistant layer is attached to the substrate by means of irregularities on the substrate's top surface. These irregularities are designed to distribute stress and minimize the number of features that would lead to crack formation and subsequent failure of the insert. These surface irregularities are not sculptured features on the substrate that are of difficult or impossible manufacture, but they can be manufactured by pre- or post-sintering shaping methods.