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CN-122013085-A - Pure titanium bipolar plate roll stamping rebound control method based on grain size and texture regulation

CN122013085ACN 122013085 ACN122013085 ACN 122013085ACN-122013085-A

Abstract

The invention discloses a pure titanium bipolar plate roll-punching rebound control method based on grain size and texture regulation, relates to the technical field of hydrogen fuel cells, and solves the technical problems that a rebound phenomenon exists in a roll-punching process of a pure titanium bipolar plate, and the formability and the dimensional stability are difficult to be considered. The rebound control method comprises the steps of sequentially carrying out atmosphere control, temperature rise, heat preservation and cooling treatment on an industrial pure titanium plate in a vacuum tube furnace, forming a recrystallized structure with average grain size of 20-35 mu m and 0001 basal plane preferred orientation under alpha phase recrystallization, so as to reduce rebound angles in a rolling direction, a transverse direction and a direction forming an included angle of 45 degrees with the rolling direction, and verifying the rebound angle control effect through finite element simulation analysis. According to the invention, alpha-phase recrystallization is realized through atmosphere control, temperature rise, heat preservation and cooling treatment, the rebound of the pure titanium bipolar plate in the roll forming process is effectively reduced, and verification is carried out through a finite element simulation model.

Inventors

  • WU YUXI
  • SUN YONG
  • REN ZHIYONG
  • HU XINYU
  • LIU CHAOHAI
  • DING WANGWANG

Assignees

  • 电子科技大学(深圳)高等研究院
  • 电子科技大学

Dates

Publication Date
20260512
Application Date
20260410

Claims (10)

  1. 1. The pure titanium bipolar plate roll stamping rebound control method based on grain size and texture regulation is characterized by comprising the following steps of: Selecting an industrial pure titanium plate with the thickness of 0.1mm as a bipolar plate raw material; Sequentially carrying out atmosphere control, heating, heat preservation and cooling treatment on an industrial pure titanium plate in a vacuum tube furnace, and forming a recrystallized structure with the average grain size of 20-35 mu m and the preferred orientation of a 0001 basal plane under alpha-phase recrystallization to reduce the rebound angles of the rolling direction, the transverse direction and the direction forming an included angle of 45 degrees with the rolling direction so as to obtain the pure titanium bipolar plate to be roll-punched; Based on the flow channel forming parameters of the pure titanium bipolar plate, a finite element simulation model for simulating rebound behavior of the pure titanium bipolar plate in the roll forming process is established, and influences of different average grain sizes and texture orientations on rebound angles in the rolling direction, the transverse direction and the 45-degree direction are quantitatively evaluated through finite element simulation analysis, so that rebound angle control effects of the recrystallization structure with the average grain size of 20-35 mu m and the preferred orientation of 0001 basal plane on the rolling direction, the transverse direction and the direction forming an included angle of 45 degrees with the rolling direction are verified.
  2. 2. The roll-stamping rebound control method for the pure titanium bipolar plate based on grain size and texture regulation of claim 1, wherein the chemical components in the industrial pure titanium plate are less than or equal to 0.035wt% of Fe, less than or equal to 0.004wt% of C, less than or equal to 0.003wt% of N, less than or equal to 0.003wt% of H, less than or equal to 0.077wt% of O, and the balance of Ti.
  3. 3. The pure titanium bipolar plate roll stamping rebound control method based on grain size and texture regulation and control of claim 1 is characterized in that the vacuum tube furnace is an OTF-1200X vacuum tube furnace.
  4. 4. The roll-punching rebound control method for the pure titanium bipolar plate based on grain size and texture regulation and control is characterized in that the atmosphere in the vacuum tube furnace is controlled by vacuumizing and filling high-purity argon gas for three times or more, an inert gas environment with oxygen content of less than 1ppm is established, argon gas is continuously introduced for protection during the whole heat treatment process, and positive pressure of 0.03MPa in the vacuum tube furnace is maintained.
  5. 5. The method for controlling rebound of roll stamping forming of a pure titanium bipolar plate based on grain size and texture regulation of claim 1, wherein the heating operation is to raise the temperature to a target temperature at a rate of 10 ℃ per minute.
  6. 6. The pure titanium bipolar plate roll-forming rebound control method based on grain size and texture regulation and control of claim 5, wherein the target temperature is greater than the recrystallization starting temperature of metallic titanium, and the metallic titanium is only a single-phase alpha-Ti structure at the target temperature.
  7. 7. The pure titanium bipolar plate roll-forming rebound control method based on grain size and texture regulation of claim 6, wherein the target temperature is 650 ℃.
  8. 8. The method for controlling the rebound of the roll stamping of the pure titanium bipolar plate based on grain size and texture regulation and control according to claim 1, wherein the heat preservation operation is to fully recrystallize the metallic titanium at the constant temperature of 650 ℃ plus or minus 10 ℃ for 90 minutes.
  9. 9. The method for controlling the rebound of the roll stamping of the pure titanium bipolar plate based on grain size and texture regulation and control according to claim 1, wherein when the temperature is more than 500 ℃, the pure titanium bipolar plate is firstly forced to be cooled to below 500 ℃ at 10 ℃ per minute during cooling treatment, and then is cooled to room temperature along with a furnace.
  10. 10. The roll-forming rebound control method for the pure titanium bipolar plate based on grain size and texture regulation of claim 1, wherein the pure titanium bipolar plate to be roll-formed is prepared by the following steps: performing blank layout design of the pure titanium bipolar plate, and transversely rolling the blank to be parallel to the main extending direction of the bipolar plate flow channel; And (3) feeding the pure titanium bipolar plate to be roll-punched into a roll forming machine, and carrying out roll-punching forming processing based on a bipolar plate runner mold to obtain the pure titanium bipolar plate.

Description

Pure titanium bipolar plate roll stamping rebound control method based on grain size and texture regulation Technical Field The invention relates to the technical field of hydrogen fuel cells, in particular to a pure titanium bipolar plate roll stamping rebound control method based on grain size and texture regulation. Background The hydrogen fuel cell is a power generation device for directly converting chemical energy of hydrogen and oxygen into electric energy, and is regarded as a key component of a clean energy system in the future due to the characteristics of high efficiency, zero emission and rapid energy supplementing. In a hydrogen fuel cell system, a metal bipolar plate is a key core component for realizing high power density and low cost of a galvanic pile, and has multiple functions of electric conduction, heat conduction, separation of reaction gas, support of a membrane electrode and the like. Pure titanium is an ideal material for metallic bipolar plates due to its excellent corrosion resistance, good electrical conductivity, and moderate mechanical strength. However, the rebound behavior of a metallic material is affected by both its microstructure (e.g., grain size, texture, phase composition) and mechanical properties (e.g., yield strength, elastic modulus, anisotropy). For pure titanium with a Close-Packed Hexagonal (HCP) structure, a plastic deformation machine of the pure titanium is highly dependent on crystal orientation, and crystal grain coarsening generally leads to yield strength reduction and elastic recovery enhancement, and the pure titanium has rebound phenomenon in the cold forming (such as roll punching) process, so that the geometric accuracy of a runner and the consistency of battery pack assembly are seriously influenced, and the industrial application of the pure titanium is restricted. Meanwhile, the conventional heat treatment process pays attention to phase change or strength regulation and control, neglects fine control on recrystallization texture and grain uniformity, and is difficult to consider formability and dimensional stability. There is a need for a thermal-force coupling process for ultra-thin pure titanium bipolar plates that achieves synergistic optimization of microstructure and macroscopic forming properties, and effective control of roll-forming rebound of pure titanium bipolar plates. Accordingly, in carrying out the present invention, the inventors have found that there are at least the following problems in the prior art: The pure titanium bipolar plate has rebound phenomenon in the roll forming process, so that the formability and the dimensional stability are difficult to be considered, the geometric accuracy of a runner and the consistency of battery stack assembly are influenced, and the industrialization application is restricted. Disclosure of Invention The invention aims to provide a pure titanium bipolar plate roll-punching rebound control method based on grain size and texture regulation, which solves the technical problems that in the prior art, a pure titanium bipolar plate has rebound phenomenon in the roll-punching forming process, formability and dimensional stability are difficult to be considered, geometric accuracy of a runner and consistency of battery stack assembly are influenced, and industrial application is restricted. The preferred technical solutions of the technical solutions provided by the present invention can produce a plurality of technical effects described below. In order to achieve the above purpose, the present invention provides the following technical solutions: The invention provides a roll-forming rebound control method of a pure titanium bipolar plate based on grain size and texture regulation, which comprises the following steps of selecting an industrial pure titanium plate with the thickness of 0.1mm as a bipolar plate raw material, sequentially carrying out atmosphere control, heating, heat preservation and cooling treatment on the industrial pure titanium plate in a vacuum tube furnace, forming a recrystallization structure with the average grain size of 20-35 mu m and the preferential orientation of a 0001 basal plane under alpha-phase recrystallization to reduce the rebound angle of the rolling direction, the transverse direction and the direction forming an included angle of 45 degrees with the rolling direction, and establishing a finite element simulation model for simulating the rebound behavior of the pure titanium bipolar plate in the roll-forming process based on the runner forming parameters of the pure titanium bipolar plate, and quantitatively evaluating the influence of different average grain sizes and texture orientations on the rolling direction, the transverse direction and the rebound angle of 45 degrees through finite element simulation analysis so as to verify the control effect of the recrystallization structure with the average grain size of 20-35 mu m and the preferential orientati