Abstract: A powder metallurgical molding forms an interconnector or an end plate for an electrochemical cell. The molding has a chromium content of at least 80% by weight, a basic shape of a plate and one or more flow fields with structuring formed on one or both of the main faces of the molding. A ratio of a maximum diameter Dmax of the molding, measured along the main face, to a minimum thickness dmin of a core region of the molding which extends along the flow field or fields and is not affected by the structuring lies in a range of 140?Dmax/dmin?350.

Abstract: A powder metallurgical component has a chromium content of at least 80% by weight and pores and/or oxide inclusions which are present in the component. The number per unit area of a sum of pores and oxide inclusions at a cut surface through the component in at least one region is at least 10,000 per mm2.

Abstract: A powder metallurgical molded part includes a disk or plate-like main body and a row of knob-shaped and/or ridge-shaped elevations in a row direction having a height perpendicular to a main plane of the main body and a cross section with side flanks leading from an outer end contour in height direction of the elevation via rounded corner portions into curved portions with a curve radius. The curve radius merges into the surface contour of the main body and a rectilinear flank portion or tangent of the side flank lying at the point where the rounded corner portion merges into the curved portion is disposed at an angle of inclination to the main plane. At least two different angles of inclination are on the same side of the main body and the at least two different angles of inclination represent at least first and second geometries.

Abstract: A molding is produced with a disk-shaped or plate-shaped basic body having a large number of knob-like and/or web-like elevations which merge into the basic body with inclined side surfaces. The molding is produced by pressing and sintering powdery raw materials close to the final shape. First, the boundary surfaces of the basic body are pressed to final shape as far as the transition regions of the elevations and the elevations are pressed to an oversize. The projection height of the elevations from the basic body is greater than the projection height in the finally pressed state. Their side surfaces form an angle of inclination in the range from 90°-150° with the respectively adjacent boundary surface of the basic body. Then the elevations are pressed to near final shape while the angle of inclination is enlarged to a greater value.

Abstract: A powder metallurgical component has a chromium content of at least 80% by weight and pores and/or oxide inclusions which are present in the component. The number per unit area of a sum of pores and oxide inclusions at a cut surface through the component in at least one region is at least 10,000 per mm2.

Abstract: A powder metallurgical molding forms an interconnector or an end plate for an electrochemical cell. The molding has a chromium content of at least 80% by weight, a basic shape of a plate and one or more flow fields with structuring formed on one or both of the main faces of the molding. A ratio of a maximum diameter Dmax of the molding, measured along the main face, to a minimum thickness dmin of a core region of the molding which extends along the flow field or fields and is not affected by the structuring lies in a range of 140?Dmax/dmin?350.

Abstract: An interconnector, or bipolar plate, for a high-temperature solid electrolyte fuel cell is composed of a sintered chromium alloy which has sintering pores and contains >90% by weight of Cr, from 3 to 8% by weight of Fe and optionally from 0.001 to 2% by weight of at least one element of the group of rare earth metals. The chromium alloy contains from 0.1 to 2% by weight of Al and the sintering pores are at least partially filled with an oxidic compound containing Al and Cr. The interconnector has a high impermeability to gas and dimensional stability.

Abstract: A shaped part that is particularly suited as an interconnector or an end plate for a fuel cell stack, is produced by pressing and sintering a pulverulent starting material. The shaped part has a basic body with a multiplicity of knob-like and/or ridge-like elevations with a height h. Each elevation has two inclined side flanks which lead, proceeding from an end contour of the elevation, via rounded corner portions, directly or via intermediate rectilinear portions, into curved portions with a radius R or R?, which in turn merge into the surface contour, of the basic body. A ratio of the radius R:h or R?:h ranges from 0.25, or preferably from 0.5 to 1.

Abstract: A shaped part that is particularly suited as an interconnector or an end plate for a fuel cell stack, is produced by pressing and sintering a pulverulent starting material. The shaped part has a basic body with a multiplicity of knob-like and/or ridge-like elevations with a height h. Each elevation has two inclined side flanks which lead, proceeding from an end contour of the elevation, via rounded corner portions, directly or via intermediate rectilinear portions, into curved portions with a radius R or R?, which in turn merge into the surface contour, of the basic body. A ratio of the radius R:h or R?:h ranges from 0.25, or preferably from 0.5 to 1.

Abstract: A shaped part that is particularly suited as an interconnector or an end plate for a fuel cell stack, is produced by pressing and sintering a pulverulent starting material. The shaped part has a basic body with a multiplicity of knob-like and/or ridge-like elevations with a height h. Each elevation has two inclined side flanks which lead, proceeding from an end contour of the elevation, via rounded corner portions, with a radius r or r? directly or via intermediate rectilinear portions, into curved portions, with a radius R or R?, which in turn merge into the surface contour, of the basic body. The rectilinear portions, or, in the case of a direct transition of the rounded corner portions into the curved portions, the tangents at the point of the transition, have an angle of inclination relative to the surface contour, between 95° and 135°.

Abstract: A powder metallurgical molded part includes a disk or plate-like main body and a row of knob-shaped and/or ridge-shaped elevations in a row direction having a height perpendicular to a main plane of the main body and a cross section with side flanks leading from an outer end contour in height direction of the elevation via rounded corner portions into curved portions with a curve radius. The curve radius merges into the surface contour of the main body and a rectilinear flank portion or tangent of the side flank lying at the point where the rounded corner portion merges into the curved portion is disposed at an angle of inclination to the main plane. At least two different angles of inclination are on the same side of the main body and the at least two different angles of inclination represent at least first and second geometries.

Abstract: A molding is produced with a disk-shaped or plate-shaped basic body having a large number of knob-like and/or web-like elevations which merge into the basic body with inclined side surfaces. The molding is produced by pressing and sintering powdery raw materials close to the final shape. First, the boundary surfaces of the basic body are pressed to final shape as far as the transition regions of the elevations and the elevations are pressed to an oversize. The projection height of the elevations from the basic body is greater than the projection height in the finally pressed state. Their side surfaces form an angle of inclination in the range from 90°-150° with the respectively adjacent boundary surface of the basic body. Then the elevations are pressed to near final shape while the angle of inclination is enlarged to a greater value.

Abstract: The invention relates to a process for producing a molding, comprising a disk-like or plate-like basic body -5- having a large number of knob-like and/or web-like elevations -4-3- which merge into the basic body -5- with inclined side surfaces, by means of pressing and sintering powdery raw materials close to the final shape. According to the invention, the pressing is carried out in a two-stage pressing operation. In the first stage the boundary surfaces of the basic body -5- are pressed to at least the approximate final shape as far as the transition regions of the elevations -3-4- and, at the same time, the elevations -3-4- are pressed to an oversize. The projection h? of the elevations -3-4- from the basic body -5- is greater by 10%-150% as compared with the projection h from the basic body -5- in the finally pressed state. Their side surfaces form an angle of inclination ?? in the range from 90°-150° with the respectively adjacent boundary surface of the basic body -5-.

Abstract: A shaped part that is particularly suited as an interconnector or an end plate for a fuel cell stack, is produced by pressing and sintering a pulverulent starting material. The shaped part has a disc-shaped or plate-shaped basic body with a multiplicity of knob-like and/or ridge-like elevations with a height h. In cross section, each elevation has two inclined side flanks which lead, proceeding from an end contour of the elevation, via rounded corner portions, with a radius r or r? directly or via intermediate rectilinear portions, into curved portions, with a radius R or R?, which in turn merge into the surface contour, of the basic body. The rectilinear portions, or, in the case of a direct transition of the rounded corner portions, into the curved portions, the tangents at the point of the transition, have an angle of inclination ? or ?? with respect to the surface contour, in the range of 95° to 135°. The radius R or R? is in the range of 0.

Abstract: An interconnector, or bipolar plate, for a high-temperature solid electrolyte fuel cell is composed of a sintered chromium alloy which has sintering pores and contains >90% by weight of Cr, from 3 to 8% by weight of Fe and optionally from 0.001 to 2% by weight of at least one element of the group of rare earth metals. The chromium alloy contains from 0.1 to 2% by weight of Al and the sintering pores are at least partially filled with an oxidic compound containing Al and Cr. The interconnector has a high impermeability to gas and dimensional stability.

Abstract: Highly dense shaped parts are produced with a powder metallurgic process. The parts are formed of an alloy that, besides of at least 20 weight % chromium, consists of iron and one or several additional alloy portions that in sum do not amount to more than 10 weight %. The part is produced by pressing and sintering to near final shape a ready-to-press powder where the additional alloy portions are introduced in form of a master-alloy powder. The master-alloy may contain the following variations: the additional alloy portions and the iron portions; or the additional alloy portions, the iron parts, and the chromium portions; or additional alloy portions and the chromium portions.

Abstract: The invention relates to a process for producing a molding, comprising a disk-like or plate-like basic body —5— having a large number of knob-like and/or web-like elevations —4—3— which merge into the basic body —5— with inclined side surfaces, by means of pressing and sintering powdery raw materials close to the final shape. According to the invention, the pressing is carried out in a two-stage pressing operation. In the first stage the boundary surfaces of the basic body —5— are pressed to at least the approximate final shape as far as the transition regions of the elevations —3—4— and, at the same time, the elevations —3—4— are pressed to an oversize. The projection h? of the elevations —3—4— from the basic body —5— is greater by 10%-150% as compared with the projection h from the basic body —5— in the finally pressed state. Their side surfaces form an angle of inclination ?? in the range from 90°-150° with the respectively adjacent boundary surface of the basic body —5—.

Abstract: Highly dense shaped parts are produced with a powder metallurgic process. The parts are formed of an alloy that, besides of at least 20 weight % chromium, consists of iron and one or several additional alloy portions that in sum do not amount to more than 10 weight %. The part is produced by pressing and sintering to near final shape a ready-to-press powder where the additional alloy portions are introduced in form of a master-alloy powder. The master-alloy may contain the following variations: the additional alloy portions and the iron portions; or the additional alloy portions, the iron parts, and the chromium portions; or additional alloy portions and the chromium portions.