Method and apparatus for manufacturing a fuel cell electrode
A method of manufacturing a fuel cell electrode includes stamping an electrode workpiece ( 50, 50′ ) in a sequence configured to control and/or reduce material growth, such as stamping discrete sections of the electrode workpiece in a sequential order. The method can employ a die with a die face ( 18, 18′ ) having a plurality of projections ( 24, 24′ ), wherein each projection has a top surface ( 26, 26′ ) with a concave curve along at least one plane to control and/or reduce material growth during a stamping operation.
1. A method of manufacturing a fuel cell electrode comprising:
providing a blank work piece having a slotted region with slots in rows separated from each other by struts along an X-direction and columns separated from each other by ribs along a Y-direction, and defining a centerline C extending through the middle of the slotted region along the X-direction;
sequentially stamping the blank work piece with a die along the Y-direction to create voids and lands in the struts; and
sequentially stamping the blank work piece with the die along the X-direction to create voids and lands in the ribs;
wherein the stamping sequence is configured to minimize material growth.
2. The method of claim 1 wherein the stamping sequence along the Y-direction is first striking the blank work piece near the centerline C and then sequentially striking the blank work piece toward the outside of the slotted region.
3. The method of claim 2 wherein the stamping sequence along the Y-direction comprises three strikes.
4. The method of claim 1 wherein the stamping sequence along the X-direction is first striking the blank work piece near a lateral margin of the slotted region and then sequentially striking the blank work piece toward the centerline C.
5. The method of claim 4 wherein the stamping sequence along the X-direction comprises five strikes.
6. The method of claim 1 further comprising one of qualifying the stamped work piece to ensure that the voids have a substantially uniform height, trimming the stamped work piece, flattening the stamped work piece, and finishing the stamped work piece.
7. The method of claim 1 further comprising preforming the blank work piece with the slotted region.
8. The method of claim 1 further comprising a third stamping step to create dimples in areas that will become inlet and outlet header portions of an anode.
9. The method of claim 1 wherein the die comprises a die face having a plurality of raised projections, each raised projection having a top surface and lateral sides, each lateral side joined to the top surface at a raised shoulder, wherein the top surface is concave having a nadir equidistant from the shoulders, and wherein adjacent projections are separated from each other by a plateau.
10. The method of claim 9 wherein the top surface is concave in a single plane.
11. The method of claim 9 wherein the top surface (is concave in at least two perpendicular planes such that each projection has four raised corners.
12. The method of claim 9 wherein the lateral sides are angled.
13. The method of claim 9 wherein each projection extends generally along a length of the die face parallel to a side surface of the die.
14. The method of claim 9 wherein the projections are arranged in a grid-like pattern across the die face.
15. The method of claim 6 further comprising preforming the blank work piece with the slotted region.