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 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 probe for friction stir welding MMCs, ferrous alloys, non-ferrous alloys, and superalloys, as well as non-ferrous alloys, the probe including a shank, a shoulder, and a pin disposed through the shoulder and into the shank, wherein the pin and the shoulder at least include a coating comprised of a superabrasive material, the pin and shoulder being designed to reduce stress risers, disposing a collar around a portion of the shoulder and the shank to thereby prevent movement of the shoulder relative to the shank, and incorporating thermal management by providing a thermal flow barrier between the shoulder and the shank, and between the collar and the tool.

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.

Abstract: A friction stir welding anvil and method of producing a friction stir welding anvil that precludes diffusion or mechanical bonding of the anvil to the work pieces are provided. The alternatives for producing such an anvil comprise coating the anvil with diffusion barriers such as oxides, nitrides, intermetallics, and/or refractory metals; manufacturing an anvil either completely or partially from the same; or placing a coating of such materials in the form of a thin sheet or a powder between the anvil and the work pieces. The anvil disclosed herein exhibits high strength and hardness even at elevated temperatures, such as those greater than 800° C., so as to prevent the anvil from mechanically or diffusion bonding to the work pieces and so as to minimize, or eliminate altogether, anvil deformation.

Abstract: The present invention relates to a method of joining segments of high melting temperature materials, that includes frictionally heating a first high melting temperature material and a second high melting temperature material wherein the first high melting temperature material and second high melting temperature material are welded together, without substantially changing the macrostructure and/or the microstructure of the first high melting temperature material and the second high melting temperature material, after application of a frictional force.

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.

Abstract: A system and method for performing friction stir welding of non-planar materials having high melting temperatures, wherein a process is provided for performing longitudinal and radial welds on objects such as pipes, flanges, tanks, and shrouds, and wherein an active or passive mandrel provides support for the friction stir welding process.

Abstract: A system and method of using friction stir welding and friction stir processing to perform crack repair or preventative maintenance of various materials and structures, wherein the structures include pipeline, ships, and nuclear reactor containment vessels, wherein the friction stir welding and processing can be performed on various materials including metal matrix composites, ferrous alloys, non-ferrous alloys, and superalloys, and wherein the friction stir welding and processing can be performed remotely and in harsh environments such as underwater or in the presence of radiation.

Abstract: A probe for friction stir welding MMCs, ferrous alloys, non-ferrous alloys, and superalloys, as well as non-ferrous alloys, the probe including a shank, a shoulder, and a pin disposed through the shoulder and into the shank, wherein the pin and the shoulder at least include a coating comprised of a superabrasive material, the pin and shoulder being designed to reduce stress risers, disposing a collar around a portion of the shoulder and the shank to thereby prevent movement of the shoulder relative to the shank, and incorporating thermal management by providing a thermal flow barrier between the shoulder and the shank, and between the collar and the tool.

Abstract: A probe for friction stir welding MMCs, ferrous alloys, non-ferrous alloys, and superalloys, as well as non-ferrous alloys, the probe including a shank, a shoulder, and a pin disposed through the shoulder and into the shank, wherein the pin and the shoulder at least include a coating comprised of a superabrasive material, the pin and shoulder being designed to reduce stress risers, disposing a collar around a portion of the shoulder and the shank to thereby prevent movement of the shoulder relative to the shank, and incorporating thermal management by providing a thermal flow barrier between the shoulder and the shank, and between the collar and the tool.

Abstract: A polycrystalline diamond (PCD) body with improved thermal stability is disclosed which comprises a PCD body which has had at least one of its previously empty pores infiltrated by a silicon containing alloy. According to the process of the invention, a porous PCD body is obtained, preferably by acid leaching a PCD body which was formed in the presence of a metal catalyst such as cobalt. The porous PCD body is then surrounded by either the desired silicon containing alloy, or by the constituents of that alloy, each preferably in powdered form. The PCD body with its surrounding material is then heated and pressed to temperatures sufficient to melt the surrounding material (thereby forming the silicon alloy if not already formed) and to cause it to infiltrate into the pores. After the infiltration, it is preferred to remove the excess silicon containing alloy from the external surfaces of the PCD body, such as by an acid bath. It is also preferred to include several porous PCD bodies per process cycle.

Abstract: Scratch-free polished diamond is obtained by rubbing a surface of the diamond to be polished against a smooth complementary diamond surface with sufficient pressure and velocity to heat the surface being polished above the spontaneous thermal degradation temperature of the diamond. Such a method can be used to burnish diamond-on-diamond bearings in as little as ten minutes as compared with up to three weeks by prior polishing techniques. Excessive thermal degradation of the diamond is avoided by cooling the surface being polished, preferably by cooling intermittently. The same techniques are usable for other superhard material such as cubic boron nitride.