Powder metal friction stir welding tool and method of manufacture thereof
View Patent ↗A method of manufacturing a friction stir tool that has an axis of rotation and a welding tip that is made of powdered metal material.
1. A method of manufacturing a friction stir welding tool including the steps of:
forming a shank of a metal material;
compacting a ferrous-based powder to form a welding tip of ferrous-based material including a plurality of pores;
extending the welding tip centrally from a free end of the shank so that the welding tip presents a working free end spaced from the free end of the shank for plunging into abutting work pieces;
sintering the welding tip at about ambient pressure which is not under vacuum; and
steam treating the welding tip to form Fe 3 O 4 in the plurality of pores.
2. The method of claim 1 wherein said sintering is conducted in a continuous furnace.
3. The method of claim 1 wherein said step of fanning the shank includes compacting and sintering a metal material separately from the welding tip and including the step of joining the shank and the welding tip to one another.
4. The method of claim 1 wherein said steam treating further comprises converting an exposed surface of the welding tip to Fe 3 O 4 .
5. A method of manufacturing a friction stir welding tool including the steps of:
forming a shank of a metal material;
compacting a ferrous-based powder to form a welding tip of ferrous-based material including a plurality of pores; and wherein at least a portion of the welding tip contains Fe 3 O 4 oxide
extending the welding tip centrally from a free end of the shank so that the welding tip presents a working free end spaced from the free end of the shank for plunging into abutting work pieces;
sintering the welding tip at about ambient pressure which is not under vacuum; and
impregnating a resin in the plurality of pores under a vacuum.
6. A method of manufacturing a friction stir welding tool including the steps of:
forming a shank of a metal material;
compacting a ferrous-based powder to form a welding tip of ferrous-based material including a plurality of pores; and wherein at least a portion of the welding tip contains Fe 3 O 4 oxide
extending the welding tip centrally from a free end of the shank so that the welding tip presents a working free end spaced from the free end of the shank for plunging into abutting work pieces;
sintering the welding tip together with another material having a lower melting point than the ferrous-based material at about ambient pressure which is not under vacuum;
said sintering including infiltrating the material having a lower melting point than the ferrous-based material in the plurality of pores of the welding tip.
7. A method of manufacturing a friction stir welding tool including the steps of:
forming a shank of a metal material;
mixing a ferrous-based powder with at least one additive selected from the group consisting of: CaF 2 , MnS, MoS 2 , BN, CaCO 3 , SiO 2 , Al 2 O 3 , ceramic, carbide compounds, ferro-nickel, ferro-nickel, chromium, and an alloy of Cr, Ni, and Co;
compacting the mixture of the ferrous-based powder and the at least one additive to form a welding tip of the mixture; and wherein at least a portion of the welding tip contains Fe 3 O 4 oxide
extending the welding tip centrally from a free end of the shank so that the welding tip presents a working free end spaced from the free end of the shank for plunging into abutting work pieces; and
sintering the welding tip at about ambient pressure which is not under vacuum.