KR-20260066841-A - Method for manufacturing separator for fuel cell

Abstract

The present invention relates to a method for manufacturing a separator plate for a fuel cell, and more specifically, aims to provide a method for manufacturing a separator plate for a fuel cell that can correct warping deformation of the separator plate caused by springback after stamping molding during the manufacturing of the separator plate for a fuel cell.

Inventors

• 박재봉
• 김성환

Assignees

• 현대자동차주식회사
• 기아 주식회사

Dates

Publication Date

20260512

Application Date

20241105

Claims (6)

1. A first step of forming a separator material into a predetermined separator shape through stamping molding; A second step of applying a load of 2.5 tons or less to the separator material while heating the separator material to 400℃ or lower; A method for manufacturing a separator for a fuel cell including
2. In claim 1, In the second step above, the separator material is A method for manufacturing a separator for a fuel cell, characterized by being placed in a hot straightening mold heated to 200°C or higher and 400°C or lower, and being pressurized to 1.0 ton or higher and 2.5 ton or lower within the hot straightening mold.
3. In claim 1, A method for manufacturing a separator for a fuel cell, characterized by performing a process of trimming and piercing the separator material between the first and second steps.
4. In claim 1, A method for manufacturing a separator for a fuel cell, characterized in that the separator material is a coating material with a surface coating of an electrically conductive material.
5. In claim 1, A method for manufacturing a separator for a fuel cell, characterized in that the separator material is an uncoated material without an electrically conductive material coating, and an electrically conductive material is coated on the surface of the separator material after completing the second step.
6. In claim 1, A method for manufacturing a separator for a fuel cell, characterized in that the separator material is titanium.

Description

Method for manufacturing separator for fuel cell The present invention relates to a method for manufacturing a separator for a fuel cell, and more specifically, to a method for manufacturing a separator for a fuel cell that can improve warping deformation occurring during the manufacturing of the separator for a fuel cell. Generally, conventional automotive fuel cells have widely used separators made of graphite or stainless steel; however, recently, there has been increasing interest in titanium (Ti) separators, which offer excellent corrosion resistance and high specific strength, enabling lightweighting. However, due to its HCP (Hexagonal Closed Packed) crystal structure, titanium has only limited slip systems, and thus exhibits different physical properties depending on the rolling direction during plastic deformation. Typically, metal separator plates are manufactured into a specific shape through stamping. However, due to the aforementioned material characteristics, titanium separator plates experience significant warpage caused by springback when produced by stamping, which makes it difficult to ensure flatness in the finished product. These issues are causing a very high defect rate in manufacturing processes following the stamping of the separator plate, such as the rubber gasket injection molding process; therefore, there is an urgent need to improve productivity and secure profitability by reducing the defect rate. FIG. 1 is a flowchart illustrating a method for manufacturing a separator plate for a fuel cell according to an embodiment of the present invention. FIG. 2 is a schematic diagram illustrating a mold for hot straightening according to an embodiment of the present invention. FIG. 3 is a schematic diagram showing a hot straightening process according to an embodiment of the present invention. Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The details included in the accompanying drawings are schematic for the purpose of easily explaining the embodiments of the present invention and may differ from the actual implemented form. The present invention relates to a method for manufacturing a separator plate for a fuel cell, particularly a separator plate made of titanium (Ti), which can correct warping deformation of the separator plate caused by the springback phenomenon after the molding is completed during stamping molding. Referring to FIG. 1, a method for manufacturing a separator according to an embodiment of the present invention comprises a first step (S100) of preparing a separator material, a second step (S110) of cutting the prepared separator material into a sheet shape for separator molding and manufacturing, a third step (S120) of placing the cut separator material into a mold and performing stamping molding, a fourth step (S130) of performing trimming and piercing processes on the separator material after the stamping molding is completed, and a fifth step (S140) of performing hot straightening on the separator material after the trimming and piercing processes are completed. In the first step (S100) above, a separator material is prepared for use in manufacturing a separator for a fuel cell. At this time, the separator material may be one of a coated material having a surface coated with an electrically conductive material and an uncoated material not coated with an electrically conductive material. When a coated material is used as the separator material, a separate surface coating process (see S150 in FIG. 1) can be omitted compared to when an uncoated material is used, thereby reducing the production process of the separator and lowering manufacturing costs. In the second step (S110) above, the separator material is cut to a predetermined size required for manufacturing the separator. In the third step (S120) above, the separator material is processed and formed into a predetermined separator shape through multi-stage stamping molding. For example, a plurality of flow paths are processed in the separator material through a first stamping molding process and a second stamping molding process, and then the shape and dimensions of the flow paths are precisely processed through a third molding process called a restriking process. As is known, a separator for a fuel cell is provided with a plurality of flow paths for the flow of fuel, air, and cooling water. In the above fourth step (S130), a process of trimming and piercing is performed on the separator material (i.e., the separator molded product) that has completed stamping molding. During the trimming process, a shaping process is performed to remove unnecessary parts of the separator molded product, and during the piercing process, holes, etc. that were not processed during stamping molding are punched into the separator molded product. After the stamping forming of the third step (S120) and the trimming/piercing processing of the fourth step (S130) are both c