Search

CN-121992247-A - Copper alloy joined body and method for producing same

CN121992247ACN 121992247 ACN121992247 ACN 121992247ACN-121992247-A

Abstract

The present invention provides a copper alloy joined body and a method for producing the same, wherein the copper alloy joined body is an age-hardening copper alloy joined body which realizes extremely high joining strength by solution treatment and aging treatment after the resistant joining treatment. The copper alloy joined body is composed of a plurality of age-hardening copper alloy members which are diffusion-bonded to each other, and is a joined body which has been subjected to a solution treatment and an aging treatment, wherein the age-hardening copper alloy has a beryllium content of 0.7 wt% or less, and (i) the joining interface of the plurality of members disappears, and/or (ii) the joining interface of the plurality of members remains, and the thickness of an oxide film at the joining interface is 0nm or more and 5.0nm or less, and the tensile strength of the copper alloy joined body including the joined portion in hydrogen gas, measured in a low strain rate tensile test performed at a strain rate of 5 x 10 ‑5 s ‑1 or less, is 520MPa or more.

Inventors

  • Gao Sangman
  • MATSUNAGA HISAO
  • ISHIKAWA TAKAHIRO
  • UCHIYAMA HIROMITSU
  • SAKAKIBARA MASATO
  • Akawa Masaaki

Assignees

  • 国立大学法人九州大学
  • 日本碍子株式会社

Dates

Publication Date
20260508
Application Date
20211228
Priority Date
20210108

Claims (20)

  1. 1. A copper alloy joined body comprising a plurality of age-hardening copper alloy members diffusion-bonded to each other, wherein the copper alloy joined body is subjected to a solid solution treatment and an aging treatment, The age-hardenable copper alloy has a beryllium content of 0.7 wt.% or less, and (I) The joint interfaces of the plurality of members disappear, and/or (Ii) A bonding interface between the plurality of members, wherein the thickness of an oxide film of the bonding interface is 0nm or more and 5.0nm or less, The tensile strength of the copper alloy joined body including the joined portion in hydrogen gas, which is measured in a low strain rate tensile test performed at a strain rate of 5×10 -5 s -1 or less, is 520MPa or more.
  2. 2. The copper alloy joined body according to claim 1, comprising crystal grains of the age-hardenable copper alloy that have grown beyond the joining interface or have been the location of the joining interface.
  3. 3. The copper alloy joined body according to claim 1 or 2, wherein the oxide film has a thickness of 0nm or more and 1.0nm or less.
  4. 4. The copper alloy joined body according to claim 1 or 2, wherein there is no residual component from a material other than the age-hardenable copper alloy at the joint interface or at a position that was the joint interface.
  5. 5. The copper alloy joined body according to claim 1 or 2, wherein the strength of a base material and a joined portion of the copper alloy joined body is 520MPa or more.
  6. 6. The copper alloy joined body according to claim 5, wherein the strength of the base material and the joined portion of the copper alloy joined body is 690MPa or more.
  7. 7. The copper alloy joined body according to claim 1 or 2, wherein a heat conductivity coefficient of a base material of a joined portion including the copper alloy joined body is 209W/mK or more.
  8. 8. The copper alloy joined body according to claim 1 or 2, wherein the electrical conductivity of a base material of a joined portion including the copper alloy joined body is 50iacs% or more.
  9. 9. The copper alloy joined body according to claim 1 or 2, wherein the age-hardenable copper alloy is at least 1 selected from the group consisting of: Beryllium copper 11 alloy, i.e., JIS alloy No. C1751, EN material No. CW110C, and UNS alloy No. C17510; beryllium copper 10 alloy, namely EN material number CW104C and UNS alloy number C17500; beryllium copper CuCo1Ni1Be, EN material number CW103C; Beryllium copper 14Z alloy, namely, 0.2 to 0.6 weight percent of Be, 1.4 to 2.4 weight percent of Ni, 0 to 0.5 weight percent of Zr, and the balance of Cu and unavoidable impurities; Beryllium copper 50 alloy, namely, 0.2 to 0.6 weight percent of Be, 1.4 to 2.1 weight percent of Ni, 0.1 to 0.3 weight percent of Ag, 0 to 0.5 weight percent of Zr, and the balance of Cu and unavoidable impurities; the beryllium copper 10Zr alloy comprises 0.4-0.7 wt% of Be, 2.0-2.8 wt% of Co, 0-0.3 wt% of Zr and the balance of Cu and unavoidable impurities; Chromium copper, UNS alloy number C18200; chromium zirconium copper, UNS alloy number C18510, EN material number CW106C; zirconium copper, namely UNS alloy number C15000, EN material number CW120C, and Kesen copper, namely EN material No. CW109C, CW111C, UNS alloy No. C19010, C70250, AMPCO944 and AMPCO940, wherein in the AMPCO944, 6.5-7.5 wt% of Ni, 1.5-2.5 wt% of Si, 0.5-1.5 wt% of Cr, the balance of Cu and unavoidable impurities, and in the AMPCO940, 1.5-3.0 wt% of Ni, 0.5-1.5 wt% of Si, 0.3-1.5 wt% of Cr, and the balance of Cu and unavoidable impurities.
  10. 10. The copper alloy joint according to claim 9, wherein the age-hardenable copper alloy is at least 1 selected from the group consisting of: Beryllium copper 11 alloy, i.e., JIS alloy No. C1751, EN material No. CW110C, and UNS alloy No. C17510; Beryllium copper 10 alloy, EN material number CW104C and UNS alloy number C17500; beryllium copper CuCo1Ni1Be, EN material number CW103C; beryllium copper 14Z alloy, namely, 0.2 to 0.6 weight percent of Be, 1.4 to 2.4 weight percent of Ni, 0 to 0.5 weight percent of Zr, and the balance of Cu and unavoidable impurities; A beryllium copper 50 alloy, which is composed of 0.2 to 0.6 wt% of Be, 1.4 to 2.1 wt% of Ni, 0.1 to 0.3 wt% of Ag, 0 to 0.5 wt% of Zr, and the balance of Cu and unavoidable impurities, and The beryllium copper 10Zr alloy comprises 0.4-0.7 wt% of Be, 2.0-2.8 wt% of Co, 0-0.3 wt% of Zr, and the balance of Cu and unavoidable impurities.
  11. 11. The copper alloy joined body according to claim 1 or 2, which is produced using a copper alloy member having a relative reduction of area of at least 0.8, which is RRA in hydrogen gas, measured in a low-strain-rate tensile test performed at a strain rate of 5X 10 -5 s -1 or less.
  12. 12. The copper alloy joined body according to claim 1 or 2, wherein the tensile strength of the copper alloy joined body including the joined portion in hydrogen gas, measured in a low strain rate tensile test performed at a strain rate of 5 x 10 -5 s -1 or less, is 690MPa or more.
  13. 13. The copper alloy joined body according to claim 1 or 2, wherein the copper alloy joined body has a flow path space inside thereof.
  14. 14. A method for producing the copper alloy joined body according to any one of claims 1 to 13, comprising: A step of preparing a plurality of members made of an age-hardenable copper alloy having a plane surface to be joined of 0.1mm or less and a ten-point average roughness Rzjis of 6.3 μm or less, the beryllium content being 0.7 wt% or less, A step of removing oxide films present on surfaces to be joined of the plurality of members, A step of diffusion bonding the plurality of members by hot pressing to form an intermediate bonded body, A step of subjecting the intermediate joint body to solution treatment by heating at a temperature of 700-1100 ℃ for 1-180 minutes and water cooling thereafter, and And (3) aging the intermediate joint body subjected to the solution treatment for 30-480 minutes at 350-550 ℃.
  15. 15. The method according to claim 14, wherein the removal of the oxide film is performed by cleaning surfaces to be joined of the plurality of members with an inorganic acid solution.
  16. 16. The method according to claim 14 or 15, wherein the hot pressing is performed by applying a pressure of 1.0MPa or more for 30 to 480 minutes at a temperature of 500 to 1050 ℃ in a furnace having a vacuum of higher than 1.0 x 10 -2 Torr, that is, a pressure of lower than 1.0 x 10 -2 Torr.
  17. 17. The method according to claim 14 or 15, wherein the hot pressing is performed by applying a pressure of 1.0MPa or more for 30 to 480 minutes at a temperature of 500 to 1050 ℃ in a furnace having a vacuum of more than 1.0 x 10 -1 Torr, that is, a pressure of less than 1.0 x 10 -1 Torr, in the case where the age-hardenable copper alloy does not contain Be.
  18. 18. The method according to claim 14 or 15, wherein the method further comprises the step of homogenizing the intermediate joint body at 900 to 1050 ℃ for 60 to 480 minutes in a vacuum of more than 1.0X10 -1 Torr, i.e., a pressure of less than 1.0X10 -1 Torr, or in a furnace in a nitrogen or other non-oxidizing gas atmosphere, before the solution treatment.
  19. 19. The method according to claim 18, wherein the hot pressing and the homogenizing treatment are continuously performed by raising the temperature by releasing the pressing load without lowering the temperature in the furnace.
  20. 20. The method according to claim 14 or 15, further comprising a step of forming grooves that bring about flow path spaces after joining on surfaces to be joined of the plurality of members before removing the oxide film.

Description

Copper alloy joined body and method for producing same The present invention is a divisional application of the invention application No. 202180071156.7 (International application No. PCT/JP 2021/049009), application No. 2021, 12/28, and entitled "copper alloy joined body and method of manufacturing the same". Technical Field The present invention relates to a copper alloy joined body and a method for producing the same. Background A hydrogen adding station for supplying hydrogen to a fuel cell vehicle or the like is provided with a pre-cooler for rapidly supplying high-pressure hydrogen cooled to about-45 ℃. That is, when hydrogen is rapidly filled into a tank of a fuel cell vehicle or the like, the temperature of the tank rises due to adiabatic compression, which is dangerous, and therefore, by cooling the hydrogen in advance by a pre-cooler at the time of supply, high-pressure hydrogen can be safely and rapidly supplied to the fuel cell vehicle or the like. Therefore, it is preferable to use a material which is free from hydrogen embrittlement, has a tensile strength capable of withstanding high pressure, and has a thermal conductivity capable of performing efficient cooling, in the heat exchanger which is a main constituent member of the pre-cooler for the hydrogenation station. Conventionally, in a heat exchanger of a pre-cooler for a hydrogenation station, stainless steel for high-pressure hydrogen such as SUS316L (Ni equivalent material) is used from the viewpoint of not causing hydrogen embrittlement, but there is room for improvement from the viewpoints of tensile strength and thermal conductivity. Beryllium copper, which is known as a material having high tensile strength and thermal conductivity, is suitable as a material for heat exchangers, and it has been confirmed that hydrogen embrittlement does not occur even under high-pressure hydrogen gas. For example, patent document 1 (japanese unexamined patent publication No. 9-87780) discloses a beryllium copper alloy for heat exchangers, which has a Be content of 1.0 to 2.5%, a total content of Ni and Co of 0.2 to 0.6%, and the balance of Cu and unavoidable impurities, although not for use in a hydrogenation station. Patent document 2 (japanese unexamined patent publication No. 2017-145472) discloses a beryllium copper alloy having a Be content of 0.20 to 2.70 wt%, a total content of Co, ni and Fe of 0.20 to 2.50 wt%, and a total content of Cu, be, co, ni and Fe of 99 wt% or more, and is considered to Be excellent in hydrogen embrittlement resistance, tensile strength and thermal conductivity. The beryllium copper alloy has not only no hydrogen embrittlement (i.e., has hydrogen embrittlement resistance), but also a higher tensile strength (for example, about 1.5 to 2.5 times) than that of the high-pressure hydrogen stainless steel and a higher thermal conductivity (for example, about 7 to 16 times) than that of the stainless steel, and therefore, compared with a stainless steel product, the size of the high-pressure hydrogen heat exchanger (for example, about one fourth) which cannot be realized in a low-purity copper and low-strength copper alloy can be significantly reduced. Prior art literature Patent literature Patent document 1 Japanese patent laid-open No. 9-87780 Patent document 2 Japanese patent application laid-open No. 2017-145472 Disclosure of Invention The heat exchanger of the pre-cooler for the hydrogenation station has a structure in which metal plates having slits or grooves are bonded in a plurality of layers so as to form a flow path through which hydrogen and a refrigerant pass. Diffusion bonding is widely known as a bonding method of stainless steel for high-pressure hydrogen, in which an oxide film on a surface layer is sublimated and removed during a temperature rise and pressure reduction to a bonding temperature, and a bonding pressure is applied to a bonding portion at a high temperature of a melting point or lower to bond stainless steel plates to each other. However, in the case of copper alloys, (i) a strong oxide film which is difficult to remove is easily provided under a simple reduced pressure temperature rise, and/or (ii) even if the oxide film is removed before joining, the oxide film is easily reformed on the joining surface (adhesion surface) during a temperature rise under a high vacuum in the joining step (and the oxide film is difficult to sublimate even at a temperature close to the joining temperature). When the copper alloy is diffusion bonded in the same step, it is difficult to obtain a structure and strength equivalent to those of the base material, although a certain bonding strength is ensured. In particular, in order to realize a copper alloy member having extremely high strength required for the high-pressure heat exchanger application, it is necessary to subject a time-hardening copper alloy to a solution treatment and an aging treatment. However, the diffusion bonded body of age-hardening copper al