include for example metal matrix composites ferrous alloys such as steel and stainless steel non ferrous materials such as aluminum aluminum alloys and titanium super alloys such as nickel iron nickel and cobalt based alloys generally suitable for use at temperatures above 1 000 degrees fahrenheit and air hardened steels these materials may be described as u201c high melting temperature compounds u201d or compounds having a melting temperature greater than steel additional elements in the types of materials that may be friction stirred include but are not limited to diamond tungsten carbide chromium molybdenum manganese silicon carbon boron tungsten aluminum titanium niobium tantalum vanadium nickel cobalt zirconium phosphorus and rhenium additive materials may be applied to the back face of a drill bit leg including over the ball hole plug weld by any means known in the art as described in u s patent application ser no ______ attorney docket number 05516 446001 which is filed concurrently herewith and is incorporated by reference in its entirety for example additive material may be applied as hard particles as a tape or as a plate to the leg base material prior to friction stirring methods of application include thermal spraying plasma spraying using adhesives to bind the friction stirring material to the base material entrenching a packed powder into the surface of the base material sandwiching a first friction stirring material between the base material and a second friction stiffing material etc alternatively the additive material may have been welded to a base material using a variety of conventional techniques such as gmaw gas metal arc welding gtaw gas tungsten arc welding pta plasma transferred arc fcaw flux cored arc welding etc due to the phase transformations.