Abstract: A composition for drill bit bodies and a method for making drill bits from the composition are disclosed. The composition includes powdered tungsten carbide, and binder metal consisting of a composition by weight of manganese in a range of about zero to 25 percent, nickel in a range of about zero to 15 percent, zinc in a range of about 3 to 20 percent, tin in a range of more than 1 percent to about 10 percent, and copper making up the remainder by weight of the composition. In one embodiment, the composition includes about 6 to 7 percent tin therein. The composition is heated to at least the infiltration temperature in a mold for form a drill bit body.

Abstract: A new composition for making an improved high-strength matrix body and methods of making the matrix body are disclosed. The new composition includes large-grain carburized tungsten carbide, an infiltration binder, and optionally cast tungsten carbide. The high-strength matrix body is formed from the new composition by an infiltration process. Suitable infiltration binders include all transition metals and all main group metals. To obtain optimal physical properties, large-grain carburized tungsten carbide is mixed with cast tungsten carbide and Ni powder before infiltration. The high-strength matrix body has improved braze strength. Such matrix bodies are suitable for manufacturing bit bodies for PDC drill bits and other earth-boring devices.

Abstract: A composition for drill bit bodies and a method for making drill bits from the composition are disclosed. The composition includes powdered tungsten carbide, and binder metal consisting of a composition by weight of manganese in a range of about zero to 25 percent, nickel in a range of about zero to 15 percent, zinc in a range of about 3 to 20 percent, tin in a range of more than 1 percent to about 10 percent, and copper making up the remainder by weight of the composition. In one embodiment, the composition includes about 6 to 7 percent tin therein. The composition is heated to at least the infiltration temperature in a mold for form a drill bit body.

Abstract: A polycrystalline diamond cutter having a coating of refractory material applied to the polycrystalline diamond surface increases the operational life of the cutter. The coating typically has a thickness in the range of from 0.1 to 30 .mu.m and may be made from titanium nitride, titanium carbide, titanium carbonitride, titanium aluminum carbonitride, titanium aluminum nitride, boron carbide, zirconium carbide, chromium carbide, chromium nitride, or any of the transition metals or Group IV metals combined with either silicon, aluminum, boron, carbon, nitrogen or oxygen. The coating can be applied using conventional plating or other physical or chemical deposition techniques.

Abstract: A method to apply a high performance overlay to a metal substrate of a rock bit to render the substrate surfaces of the rock bit more resistant to erosion, corrosion and substrate cracking while performing in an earthen formation is described. The method comprises the steps of bombarding the surfaces with a thermal spray of entrained fine particles of a cermet based composition at a velocity in excess of 3,000 ft/per sec. The resultant coating of the cermet based composition has a tensile bond strength in excess of 20,000 psi that results in an increase of the strain to fracture of the rock bit surface. The hard overlay has a resistance to severe service environments of high strain and shock tolerance as well as a higher load carrying capacity.