Abstract: A system and method for using Friction Stir Spot Joining (FSSJ) to join workpieces made of Advanced High Strength Steels (AHSS), wherein a first embodiment is a FSSJ tool that has no surface features, and wherein the rate of rotation of the FSSJ tool is much higher than is used in other FSW techniques to thereby reduce torque by causing plasticization of the AHSS on a small scale, and in a second embodiment, conventional FSSJ tools can be used at conventional FSSJ speeds if the FSSJ tool is manufactured from conductive tool materials having a high hardness, and heating of the FSSJ tool and/or the workpieces enhances the ability of the FSSJ tool to functionally weld the AHSS.

Abstract: A method is taught for creating a hollow sphere that is created by joining two cylinders together that have a semispherical hollow formed in the ends being joined together, wherein a metallic reinforcing disk is inserted at an interface between the two ends of the cylinders, wherein the two cylinders and reinforcing disk are joined using friction stir welding to create an inner sphere from the two hemispherical hollows that is bisected by the metallic reinforcing disk, and wherein the joined cylinders and reinforcing disk are machined to thereby create an outer spherical surface that is centered around the inner sphere.

Abstract: An ultra-hard construction is disclosed that is prepared by a method comprising the steps of treating a material microstructure having a polycrystalline matrix first phase material and a second phase material from at least a partial region of the material microstructure, wherein the second phase material is disposed within interstitial regions of the material microstructure, and wherein removal of the second phase material creates a porous material microstructure characterized by a plurality of empty voids and replacing the removed second phase material with a replacement material having a thermal characteristic that more closely matched polycrystalline matrix first phase that the second phase material.

Abstract: A mandrel that provides a counter-force to the pressure exerted on the outside of a pipe or other arcuate surface by a friction stir welding tool, wherein the mandrel is expandable through the use of a wedge, and wherein the mandrel enables multiple friction stir welding heads to simultaneously perform welding on the arcuate surface.

Abstract: Ultra-hard constructions include an ultra-hard body having a first region including a polycrystalline matrix first phase and a second phase material interposed therein. The first region is substantially free of a catalyst material used to form the first phase. The body is formed by removing the catalyst material and then replacing it with the second phase material. A second region is disposed within the body and includes the polycrystalline matrix first phase and a catalyst material used to form the first phase. The second phase material has a thermal characteristic that is more closely matched to the matrix first phase than the catalyst material. The body may be joined to a substrate, and the ultra-hard body may consist entirely of the first region. The second phase material can include non-refractory metals, ceramics, silicon, silicon-containing compounds, diamond, cubic boron nitride, polycrystalline diamond, polycrystalline cubic boron nitride, and mixtures thereof.

Abstract: A method of selecting a geometry for a friction stirring tool, said tool having a melting point that is higher than the workpiece material, wherein the tool is placed in motion against the workpiece to generate heat in the workpiece such that workpiece material is transported in surface features of the tool, and wherein surface features manage workpiece material flow around the tool, and wherein the tool can be used in friction stir processing, friction stir mixing, friction stir welding, and friction stir spot welding of high melting temperature materials or high softening temperature materials.

Abstract: A new control variable is introduced, that when combined with previous dependent control criteria on other variables results in a control program that can create a superior weld while minimizing wear on the FSW tool, wherein the tool repeatedly experiences the same thermal and mechanical loading within specified control windows during every repeated weld sequence because flow stresses and tool loads are driven by temperature, and dependent control loops account for differences in material and heat that is transferred at different rates in varying locations throughout a friction stir weld.

Abstract: A system and method for friction stir welding of small diameter tubing, wherein the small diameter tubing is held in a correct position with a grasp sufficient to perform FSW when the tubing is comprised of high melting temperature materials, wherein the small diameter tubing can be rotated by the positioning and holding system while a FSW tool is held stationary, or vice versa, wherein internal mandrels are also described which can fit inside the smaller dimensions of the small diameter tubing and expand to provide a counter force to prevent deformation of the tubing when forces are applied by the FSW tool, wherein new FSW tool geometries are also described which enable the FSW tool to direct more heat on a tool/workpiece interface to counteract a lack of contact between the FSW shoulder and the workpiece because of tube curvature, and wherein the FSW tool is positioned on a small diameter tube by trailing the joint to provide desirable heating at the joint/workpiece interface and surface finishing.

Abstract: A friction stir tool is provided to perform friction stir riveting using a partially consumable pin, wherein the pin includes a cutting edge on a bottom surface thereof, wherein the tool is rotated at a first speed to enable cutting by the pin into a first material that is overlapping a second material, wherein after the pin has cut to a sufficient depth, the rotational speed of the tool is increased to thereby enable plasticization of the consumable pin, the first material, and the second material, wherein the tool is then rapidly decelerated until stopped, enabling diffusion bonding between the pin, the first material and the second material.

Abstract: A new control variable is introduced, that when combined with previous dependent control criteria on other variables results in a control program that can create a superior weld while minimizing wear on the FSW tool, wherein the tool repeatedly experiences the same thermal and mechanical loading within specified control windows during every repeated weld sequence because flow stresses and tool loads are driven by temperature, and dependent control loops account for differences in material and heat that is transferred at different rates in varying locations throughout a friction stir weld.

Abstract: A friction stir tool is provided to perform friction stir riveting using a partially consumable pin, wherein the pin includes a cutting edge on a bottom surface thereof, wherein the tool is rotated at a first speed to enable cutting by the pin into a first material that is overlapping a second material, wherein after the pin has cut to a sufficient depth, the rotational speed of the tool is increased to thereby enable plasticization of the consumable pin, the first material, and the second material, wherein the tool is then rapidly decelerated until stopped, enabling diffusion bonding between the pin, the first material and the second material.

Abstract: A mandrel that provides a counter-force to the pressure exerted on the outside of a pipe or other arcuate surface by a friction stir welding tool, wherein the mandrel is expandable through the use of a wedge, and wherein the mandrel enables multiple friction stir welding heads to simultaneously perform welding on the arcuate surface.

Abstract: A system and method for using friction stir welding, friction stir processing, and friction stir mixing to create pressure vessels, pipes or other containers comprised of a single material or multiple layers of different materials, and having superior strength and endurance characteristics.

Abstract: Ultra-hard constructions include an ultra-hard body having a first region including a polycrystalline matrix first phase and a second phase material interposed therein. The first region is substantially free of a catalyst material used to form the first phase. The body is formed by removing the catalyst material and then replacing it with the second phase material. A second region is disposed within the body and includes the polycrystalline matrix first phase and a catalyst material used to form the first phase. The second phase material has a thermal characteristic that is more closely matched to the matrix first phase than the catalyst material. The body may be joined to a substrate, and the ultra-hard body may consist entirely of the first region. The second phase material can include non-refractory metals, ceramics, silicon, silicon-containing compounds, diamond, cubic boron nitride, polycrystalline diamond, polycrystalline cubic boron nitride, and mixtures thereof.

Abstract: A roller cone drill bit includes a bit body, at least one leg extending downward from the bit body, a journal on each leg, and a roller cone mounted on each journal. A ball race is configured between each journal and roller cone, and a plurality of retention balls is disposed within each ball race. A ball hole extends from the back face of each leg to the ball race, and a ball hole plug fits within the ball hole. The ball hole plug is secured to the leg by a friction stir weld.

Abstract: A new control variable is introduced, that when combined with previous dependent control criteria on other variables results in a control program that can create a superior weld while minimizing wear on the FSW tool, wherein the tool repeatedly experiences the same thermal and mechanical loading within specified control windows during every repeated weld sequence because flow stresses and tool loads are driven by temperature, and dependent control loops account for differences in material and heat that is transferred at different rates in varying locations throughout a friction stir weld.

Abstract: A roller cone drill bit includes a bit body and at least one leg extending downward from the bit body. Each leg includes an outer surface, a ball hole plug located in the outer surface, a shoulder, a shirttail, and a roller cone rotatably mounted to the leg. The outer surface of each leg is surface processed by friction stirring.

Abstract: A tool is provided that is capable of friction stir processing, friction stir mixing, and friction stir welding of high melting temperature and low melting temperature materials, wherein the collar is now divided into at least an inner and an outer collar coupled to the shank and the FSW tip, wherein new thermal barriers enable expansion of the inner collar to be directed inward to thereby create compression on the FSW tip instead of allowing the FSW tip to become loose in the tool at elevated temperatures.

Abstract: A mandrel that provides a counter-force to the pressure exerted on the outside of a pipe or other arcuate surface by a friction stir welding tool, wherein the mandrel is expandable through the use of a wedge, and wherein the mandrel enables multiple friction stir welding heads to simultaneously perform welding on the arcuate surface.

Abstract: A friction stir welding system that enables clamping of a pipe to enable friction stir welding around the pipe OD, a movable mandrel that provides a counter-force to the pressure exerted on the outside of a pipe by a tool, and a system for providing friction stir welding and repair inside a nuclear vessel in an underwater environment.