Powder metal friciton stir welding tool and method of manufacture thereof

1. A friction stir welding tool having a welding tip fabricated of ferrous-based powder metal material, and wherein at least a portion of the welding tip contains Fe 3 O 4 oxides.

2. The friction stir welding tool of claim 1 wherein the welding tip includes a plunger nib and a shoulder.

3. The friction stir welding tool of claim 1 wherein the ferrous-based powder metal material is admixed with at least one of alumina, carbide, ferro-molybdenum, ferro-nickel, chrome or tribaloy.

4. The friction stir welding tool of claim 2 wherein the powder metal material has gradient properties in which the tip has different properties than that of the shoulder.

5. The friction stir welding tool of claim 4 wherein the tip has higher wear resistance characteristics than that of the shoulder.

6. The friction stir welding tool of claim 1 wherein the entire tool is fabricated of powder metal.

7. The friction stir welding tool of claim 2 , wherein the tip and shoulder regions of the tool are fabricated of different materials.

8. The friction stir welding tool of claim 7 wherein the tip and shoulder regions are constructed separately from one another.

9. The friction stir welding tool of claim 8 wherein the tip and shoulder regions are sintered to one another.

10. The friction stir welding tool of claim 1 wherein a central core of the tool is fabricated of a different material than that of an outer sheath of the material.

11. The friction stir welding tool of claim 7 wherein the tip of the tool is made of the core material and the shoulder is made of the sheath material.

12. The friction stir welding tool of claim 1 wherein porosity of the powder metal material is infiltrated with a material having a lower melting temperature prior to compacting.

13. The friction stir welding tool of claim 1 wherein porosity of the powder metal material is impregnated with resin.