ENGINEERED ENHANCED INSERTS FOR ROCK DRILLING BITS

摘要

Enhanced inserts are formed having a cylindrical grip and a protrusion extending from the grip. An ultra hard material layer is bonded on top of the protrusion. T he inserts are mounted on a rock bit and contact the earth formations off center. The ultra hard material layer is thickest at a critical zone which encompasses a major portion of the regi on of contact between the insert and the earth formation. Transition layers may also be formed between the ultra hard material layer and the protrusion so as to reduce the residual stresses form ed on the interface between the ultra hard material and the protrusion.