Patent ID: 8910730
Filing Date: 2014-12-16
Classification: B22F,C22C,E21B

Abstract:
1. A cutting element comprising: a multilayered polycrystalline diamond element having a working surface comprising an end working surface and a peripheral working surface extending from the end working surface around the periphery of the element to a depth below the end working surface, the diamond element further comprising at least a first layer adjacent the end working surface and surrounded by the peripheral working surface, and a second layer below the first layer, the first layer comprising different diamond particles than the second layer, the first layer and the second layer sintered to a substrate of a less hard material, the polycrystalline diamond element defining a matrix of interstitial volumes, the interstitial volumes of a first region of the diamond element adjacent the working surface thereof being substantially free of a catalyzing material, the interstitial volumes of a second region of the diamond element remote from the working surface containing the catalyzing material, the first region of the diamond element extending from the end working surface and through the first layer and at least a portion of the second layer, the first region further extending through an area defined by the end working surface and at least part of the peripheral working surface and a depth extending below the end working surface, the first and second layers forming a series of steps of different sizes, the first layer adjacent to the working surface having a radius greater than a radius of the second layer.