Process for producing an interconnector of a high-temperature fuel cell

A process for producing a molding with a basic body having a multiplicity of elevations merging into the basic body with inclined side surfaces, the method which comprises the following steps:

• providing a chromium-based powder containing elemental chromium and pressing the chromium-based powder in a two-stage pressing operation with a first pressing stage and a subsequent, second pressing stage;
• and
• in the first pressing stage, providing the powder press with a first set of dies and pressing the chromium-based powder, wherein the dies are set to press the elevations with a defined oversize resulting from the first pressing stage with:
• a projection height h′ from the basic body greater than a projection height h from the basic body in a finally pressed state by 10%-150%;
• and
• side surfaces of the elevations enclosing an angle of inclination α′ between 90° and 150° with a respectively adjacent boundary surface of the basic body;
• in the second pressing stage, providing the powder press with a second set of dies, different from the first set of dies, and pressing the elevations with the second dies to near final shape, by reducing the height of the elevations from the height h′ to the height h by a greater amount than a reduction in a thickness of the basic body in the adjacent boundary surfaces and by increasing the angle of inclination α′ to α value a in a range from 95°-170°;
• and
• subsequently sintering the basic body to produce the molding.

A process of producing an interconnector for a high-temperature fuel cell, the process comprising:

• providing a powder press with dies substantially corresponding to a final shape of the interconnector, with a basic body having a multiplicity of elevations projecting from the basic body with inclined side surfaces;
• providing a chromium-based powder containing a major proportion of elemental chromium and a minor proportion of at least one additional alloying metal, and filling the powder into a female die of the powder press;
• pressing the chromium-based powder to form the basic body having a shape of a disk or a plate with the elevations defining flow channels of the high-temperature fuel cell and the elevations rising from the basic body with inclined side surfaces having an angle of inclination of between 115° and 160°;
• subsequently ejecting the basic body from the dies of the powder press and sintering to form the interconnector for the high-temperature fuel cell.