Pre-formed powder delivery to powder press machine
Methods for fabricating an interconnect for a fuel cell system that include forming a metal powder into a preform structure, positioning the preform structure in a die cavity of a press apparatus, and compressing the preform structure in the press apparatus to form the interconnect. Further embodiments include use of thin inserts in the die cavity to provide reduced permeability and/or including filler material in the die cavity.
1. A method of fabricating an interconnect for a fuel cell system, comprising
providing powder to a die cavity of a press apparatus;
vibrating the powder into a desired shape in the die cavity;
detecting at least one of a frequency or an amplitude of the powder during the vibrating of the powder;
stopping the vibrating of the powder when the detected frequency or the amplitude substantially stops changing over time; and
compressing the powder in the press apparatus to form the interconnect or a preform structure of the interconnect.
2. The method of claim 1 , wherein:
vibrating the powder into a desired shape comprises vibrating the powder to fill the die cavity; and
compressing the powder comprises compressing the powder to form the interconnect.
3. The method of claim 2 , further comprising adjusting a height of protrusions on at least one punch in the press apparatus as a function of powder density prior to compressing the powder using the punch.
4. The method of claim 1 , wherein the frequency or the amplitude is detected using a laser.
5. The method of claim 1 , wherein the frequency or the amplitude is detected acoustically.
6. The method of claim 1 , further comprising stopping the vibration when the amplitude is substantially equal to an average particle size of the powder.
7. The method of claim 1 , wherein the vibration is stopped when the frequency is between 5 Hz and 5000 Hz.
8. The method of claim 1 , wherein vibration is stopped when the amplitude is between 0.01 mm and 2 mm.