Feed roller type system for continuous feeding of filler material for friction stir welding, processing and fabrication

Abstract

The present invention relates to tools and methods for disposing, coating, repairing, or otherwise modifying the surface of a metal substrate using frictional heating and compressive/shear loading of a consumable metal against the substrate. Embodiments of the invention include friction-based fabrication tooling comprising a non-consumable member with a throat and a consumable member disposed in the throat, wherein consumable filler material is capable of being introduced to the throat in a continuous manner during deposition using frictional heating and compressive/shear loading of the filler material onto the substrate. Preferred embodiments according to the invention include such tools operably configured for applying a force or displacement to the filler material during deposition. Especially preferred embodiments can include using various powder-type consumable materials or combinations during the deposition process to obtain a continuous compositional gradient in the filler material yielding a functionally graded coating on the substrate.

1 . A friction-based fabrication tool comprising:
 a non-consumable tool body with a throat having an interior cross section shaped to impart normal forces on a feed material disposed therein when rotated; and   feed rollers disposed above the non-consumable tool body and comprising means for rotating the feed rollers toward one another such that feed material disposed perpendicularly to the feed rollers is pulled between the feed rollers and is delivered continuously through the throat of the tool body during use;   wherein the tool body comprises a surface for trapping feed material loaded on the substrate in a volume between the tool body and the substrate and for forming and shearing a surface of a coating on the substrate with frictional heating and shear loading.   
     
     
         2 . The system of  claim 1 , wherein a cross section of the throat is square and sized to accommodate a complementary shaped and sized rod-type feed material.