Systems and methods for improving backward flow forming of shafts
An apparatus for backward flow forming a material may comprise a mandrel having a headstock at a proximate end of the mandrel, the mandrel configured to rotate about an axis, a plurality of rollers disposed radially outward of the mandrel configured to exert force on the material to form a work piece at a plastic deformation zone, wherein the work piece flows from the plastic deformation zone between the plurality of rollers and the mandrel toward a distal end of the mandrel, and a catcher, coaxial to the mandrel, and removably coupled to the work piece at a traveling end of the work piece.
1. A system for backward flow forming comprising:
a material;
a mandrel having a headstock at a proximate end of the mandrel, the mandrel configured to rotate about an axis;
a plurality of rollers disposed radially outward of the mandrel configured to exert force on the material and form a work piece from the material at a plastic deformation zone, wherein the work piece flows from the plastic deformation zone between the plurality of rollers and the mandrel toward a distal end of the mandrel; and
a catcher, coaxial to the mandrel, and removably coupled to the work piece at a traveling end of the work piece,
wherein the catcher is configured to travel with the traveling end of the work piece,
wherein the catcher exerts a tension in the work piece,
wherein the catcher is configured to deflect the traveling end of the work piece with respect to the axis of the mandrel by oscillating with respect to the axis of the mandrel,
wherein the deflection of the traveling end with respect to the axis of the mandrel is 5° to 15°, and
wherein shear banding is formed within the material at the plastic deformation zone in response to the deflection of the traveling end.
2. The system of claim 1 , wherein the traveling end further comprises a coupling feature.
3. The system of claim 1 , wherein the plurality of rollers are configured to travel from the distal end of the mandrel toward the headstock.
4. The system of claim 1 wherein the catcher comprises one of a grab or a clamp.
5. The system of claim 1 , wherein the mandrel comprises a complex geometry having curves, multi-radial curves, or steps.
6. A method for backward flow forming, comprising:
mounting a material on a mandrel, wherein the mandrel comprises a headstock at a proximate end of the mandrel, wherein the mandrel is configured to rotate about an axis
exerting a force on the material via a plurality of rollers disposed radially outward of the mandrel;
advancing the plurality of rollers toward the headstock of the mandrel to form a work piece from the material at a plastic deformation zone, wherein the work piece flows from the plastic deformation zone between the plurality of rollers and the mandrel toward a distal end of the mandrel;
coupling a catcher to the workpiece at a traveling end of the work piece, wherein the catcher is coaxial to the mandrel and removably coupled to the traveling end of the work piece and wherein the catcher is configured to travel with the traveling end of the work piece;
exerting, by the catcher, a tension in the work piece;
deflecting, by the catcher, the traveling end of the work piece with respect to the axis of the mandrel by oscillating with respect to the axis of the mandrel, wherein the deflection of the traveling end with respect to the axis of the mandrel is 5° to 15°, and
forming shear banding within the material at the plastic deformation zone in response to the deflection of the traveling end.
7. The method of claim 6 , further comprising machining a coupling feature in the work piece proximate the traveling end of the work piece.
8. The method of claim 6 , wherein the coupling comprises clamping the work piece to the catcher.