Cutting element with wear resistant crown.

摘要

A cutting element (10) adapted to be used in a rotary drill bit (14) is made by positioning in an appropriately shaped die cavity a quantity of a mixture (26) of tungsten carbide and 4 to 11 percent cobalt in the shape of a crown (22) for defining an outer surface for a tip portion (16) of the cutting element (10) using a pressure of less than about 600 pounds per square inch; positioning in the cavity a quantity of a mixture (24) of tungsten carbide and 12 to 17 percent cobalt sufficient to form almost all of a base portion (12) and at least an inner part of the tip portion (16) for the cutting element (10); pressing the two quantities of the mixtures (26, 24) together and into the die (28) at pressures in the range of about 10 to 15 tons per square inch; and sintering the pressed insert to form the cutting element (10).