Abstract: In one embodiment, a method of increasing a durability of a drill bit having a bit body with at least one blade disposed thereon, at least one cutter pocket disposed on the blade, and at least one cutter disposed in the cutter pocket is disclosed. The method includes brazing the at least one cutter to the at least one cutter pocket so that a braze material disposed between the at least one cutter pocket and the at least one cutter comprises an exposed surface, and overlaying at least a portion of the exposed surface with a hardfacing material, wherein the hardfacing material includes a binder having a melting point selected to avoid damaging the cutter.

Abstract: A composite structural metal use, for example, in drill bit bodies is disclosed. The metal 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 about 24 to 96 percent by weight of the composition. In one embodiment, the composition includes about 6 to 7 percent tin therein. In another embodiment, the composition includes about 0-6 percent by weight of cobalt.

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 method for manufacturing a PCD bit by isostatically or mechanically press forming a green on a metallic blank. A metallic blank is vertically suspended into a flexible vessel. Powder metal is mixed with a binder and introduced into the flexible vessel surrounding the lower end of the suspended metallic blank. The vessel is then isostatically or mechanically pressed causing the powder mixture to stick together and to the blank, forming a green on the blank. The blank and green are removed from the vessel and the exposed end of the metallic blank is chucked onto a milling machine and turned for milling the green into the shape of a PCD bit head. After the milling is completed, the green and blank are sintered, hardening the bit head shaped green and strongly bonding it to the metallic blank, forming a PCD bit wherein the hardened green is the bit head while the metallic blank is the bit pin.

Abstract: A composite mini-extended nozzle is disclosed that is designed to both resist erosion and be strong enough to withstand the shock of a downhole drilling environment. In addition, means are provided to shroud at least a portion of the extended nozzle to further protect a portion of the nozzle nearest the exit plane from downhole obstructions. A combination of materials used to form the nozzle may include a matrix of tungsten carbides with suitable binder joined to an outer metal jacket nozzle body. A third ceramic matrix material may be utilized to line or partially line an interior passage formed by the mini-extended nozzle and a reduced in diameter portion of the nozzle design may include a built-in fracture plane in the unlikely event the end of the nozzle hits an obstruction. The extended portion of the nozzle will shear off along this fracture plane thereby preventing a nozzle washout that likely would result in a trip out of the hole to repair the resultant damage to the rock bit.

Abstract: A hard facing for teeth on a milled tooth rock bit comprises at least 65% by weight of a mixture of tungsten carbide particles and a balance of steel bonding the carbide particles together and to the cutter cone of the rock bit. The tungsten carbide particle mixture comprises from 35% to 80%, and preferably from 65% to 80%, by weight 20 to 30 mesh cemented tungsten carbide, and from 20% to 65%, and preferably from 20% to 35% by weight 40 to 80 mesh single crystal monotungsten carbide.

Abstract: A new and improved tungsten carbide insert for rock bits is disclosed, in which the inserts are subject to extended vibratory tumbling in order to increase their fracture toughness. More specifically the vibratory finishing or tumbling of the inserts has been increased from a typical time of 30-60 minutes to time periods of at least 90 minutes and preferably a minimum of 225 minutes. A marked improvement in toughness is obtained by this process because the size and distribution of surface flaws of the inserts were greatly reduced, and because the surface hardness of the inserts was increased, thereby resulting in an increase in the stress required to cause fracture, and a consequent increase in resistance to breakage.

Abstract: A hard facing for teeth on a milled tooth rock bit comprises at least 65% by weight of a mixture of tungsten carbide particles and a balance of steel bonding the carbide particles together and to the cutter cone of the rock bit. The tungsten carbide particle mixture comprises from 35% to 80%, and preferably from 65% to 80%, by weight 20 to 30 mesh cemented tungsten carbide, and from 20% to 65%, and preferably from 20% to 35% by weight 40 to 89 mesh single crystal monotungsten carbide.