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CN-122013081-A - Cryogenic cycle stress release method for monocrystalline copper component

CN122013081ACN 122013081 ACN122013081 ACN 122013081ACN-122013081-A

Abstract

The invention relates to the technical field of cryogenic cyclic stress release methods, and discloses a cryogenic cyclic stress release method of a monocrystalline copper component, which comprises the steps of selecting monocrystalline copper with extremely low inherent stress as a base material, putting the monocrystalline copper component into a liquid nitrogen environment, reducing the temperature of the monocrystalline copper component to-196 ℃ at the cooling speed of 40-60 ℃ per minute, preserving the temperature of the monocrystalline copper component for 30-60 minutes at-196 ℃, taking out the monocrystalline copper component subjected to cryogenic treatment from the liquid nitrogen, and naturally cooling the monocrystalline copper component to room temperature. According to the deep cooling circulation stress release method of the monocrystalline copper component, residual stress in the monocrystalline copper component is fully released through liquid nitrogen deep cooling and high-temperature aging treatment, deformation is avoided when the component is repeatedly used in an environment of-70 ℃ to 180 ℃, grain boundary stress is eliminated from the source by using high-purity monocrystalline copper, long-term stability of the component is further improved, high electric conductivity and thermal conductivity of the monocrystalline copper are beneficial to reducing accumulation of thermal stress, and performance of the component in an extreme temperature environment is improved.

Inventors

  • LI JIAN
  • PAN JIANFENG

Assignees

  • 江苏海鋆自动化技术有限公司

Dates

Publication Date
20260512
Application Date
20260326

Claims (9)

  1. 1. A method for releasing stress of a single crystal copper member by cryogenic cycle, comprising the steps of: 1) Single crystal copper with extremely low inherent stress is selected as a base material; 2) Placing the monocrystalline copper component in a liquid nitrogen environment, and reducing the temperature to-196 ℃ at a cooling speed of 40-60 ℃ per minute; 3) Preserving the temperature at-196 ℃ for 30-60 minutes; 4) Taking out the monocrystalline copper component subjected to the deep cooling treatment from liquid nitrogen, and naturally cooling to room temperature; 5) Heating the single crystal copper member to 300 ℃ at a heating rate of 15-30 ℃ per minute; 6) Preserving heat for 30-60 minutes at 300 ℃; 7) Rapidly cooling the single crystal copper component using water at a temperature of no more than 40 ℃; 8) Repeating the above deep cooling-high temperature circulation treatment for 3-5 times.
  2. 2. The method for releasing stress of a copper single crystal member according to claim 1, wherein the purity of the copper single crystal is not lower than 99.99%.
  3. 3. The method for releasing stress of a single crystal copper member according to claim 1, wherein the cooling rate is controlled at 50 ℃.
  4. 4. The method for releasing stress of a single crystal copper member according to claim 1, wherein the temperature rising rate is controlled at 20 ℃.
  5. 5. A method of stress relief in a single crystal copper component by cryogenic cycling according to claim 1, wherein the time interval between cycles is no more than 1 hour during repeated cryogenic-high temperature cycling.
  6. 6. The method for relieving stress of a copper single crystal member according to claim 1, wherein the surface of the copper single crystal member is subjected to a surface blasting or polishing treatment after the deep cooling-high temperature cycle treatment to remove an oxide layer and microcracks on the surface.
  7. 7. A method for releasing stress of a single crystal copper member by deep cooling circulation according to claim 1, wherein during the treatment, non-destructive inspection such as ultrasonic inspection or X-ray inspection is periodically performed on the single crystal copper member to ensure that no new defects are generated inside the material.
  8. 8. A method of cryogenic cyclic stress relief for single crystal copper components as defined in claim 1, wherein equipment and operating environment are kept clean during processing to avoid impurities affecting material properties.
  9. 9. The method for releasing stress of a copper single crystal member according to claim 1, wherein the copper single crystal member can be repeatedly used without deformation in an environment of-70 ℃ to 180 ℃ after being treated by the stress releasing method.

Description

Cryogenic cycle stress release method for monocrystalline copper component Technical Field The invention relates to the technical field of a cryogenic cycle stress release method, in particular to a cryogenic cycle stress release method for a monocrystalline copper component. Background As a high-end functional material having extremely high electrical conductivity, thermal conductivity and excellent signal transmission performance due to elimination of grain boundaries, single crystal copper is inevitably subjected to temperature gradients and external forces during growth (e.g., continuous casting) and subsequent machining and forming processes, resulting in distortion of its internal lattice, thereby generating residual stresses. Although single crystal copper does not have a common stress concentration source such as a grain boundary, the existence of residual stress in the single crystal copper still brings about serious harm, in the subsequent use or storage process, the residual stress can be loosened or redistributed, so that the component is subjected to microscopic and macroscopic deformation, which is fatal to a precision instrument or a high-precision alignment component, the residual stress can accelerate fatigue damage of a material under a specific environment, the service life of the material is reduced, the single crystal copper component often needs to work under an extreme environment with a larger temperature difference (such as-70 ℃ to 180 ℃), and if the high residual stress exists in the single crystal copper component, the irreversible deformation is extremely easy to occur under the superposition effect of thermal expansion and contraction. At present, aiming at stress relief of copper and copper alloy, the following traditional methods are mainly adopted, natural aging is carried out, the method has extremely low efficiency, often needs months or even years, cannot meet the rhythm of modern industrial production, has limited stress relief effect, is difficult to thoroughly relieve deep internal stress, and has the advantages that the traditional thermal aging (annealing) can well relieve stress, but for single crystal copper, the single crystal structure is extremely easy to be damaged at high temperature (usually higher than 400 ℃), recrystallization nucleation is caused, and new crystal boundary is introduced, so that the excellent physical properties (such as ultra-high signal transmission capability) of the single crystal copper are thoroughly lost. In addition, high temperature heating tends to cause severe oxidation of the single crystal copper surface. In summary, the prior art lacks a stress release method which can not only release the residual stress in the single crystal copper efficiently and thoroughly, but also maintain the structural integrity of the single crystal copper, does not damage the excellent physical properties of the single crystal copper, and can adapt to the use environment of a wide temperature range, so that a deep cooling cycle stress release method of the single crystal copper component is provided. Disclosure of Invention (One) solving the technical problems Aiming at the defects of the prior art, the invention provides a deep cooling circulation stress release method of a monocrystalline copper component, which has the advantages of ensuring that the component is not deformed when repeatedly used in an environment of-70 ℃ to 180 ℃ by combining the characteristics of monocrystalline copper through liquid nitrogen deep cooling and high-temperature aging treatment, and the like, and solves the problems in the prior art. (II) technical scheme In order to achieve the purpose of ensuring that the component is not deformed when being repeatedly used in an environment of-70 ℃ to 180 ℃ by combining the characteristics of single crystal copper through liquid nitrogen cryogenic treatment and high temperature aging treatment, the invention provides the following technical scheme that: 1) Single crystal copper with extremely low inherent stress is selected as a base material; 2) Placing the monocrystalline copper component in a liquid nitrogen environment, and reducing the temperature to-196 ℃ at a cooling speed of 40-60 ℃ per minute; 3) Preserving the temperature at-196 ℃ for 30-60 minutes; 4) Taking out the monocrystalline copper component subjected to the deep cooling treatment from liquid nitrogen, and naturally cooling to room temperature; 5) Heating the single crystal copper member to 300 ℃ at a heating rate of 15-30 ℃ per minute; 6) Preserving heat for 30-60 minutes at 300 ℃; 7) Rapidly cooling the single crystal copper component using water at a temperature of no more than 40 ℃; 8) Repeating the above deep cooling-high temperature circulation treatment for 3-5 times. Preferably, the purity of the single crystal copper is not less than 99.99%. Preferably, the cooling rate is controlled at 50 ℃ per minute during the cryogenic treatment. Preferably, the te