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CN-121976084-A - Short-process preparation method of high-strength high-conductivity Cu-Ag-Sn copper alloy

CN121976084ACN 121976084 ACN121976084 ACN 121976084ACN-121976084-A

Abstract

The invention discloses a short-process preparation method of a high-strength high-conductivity Cu-Ag-Sn copper alloy, and belongs to the technical field of high-performance copper alloy materials. The alloy comprises, by mass, 0.03% -0.05% of Ag, 0.005% -0.05% of Sn, less than or equal to 0.01% of impurity, and the balance of Cu. The preparation method thoroughly eliminates the traditional homogenizing annealing and solution treatment process, and only comprises three core steps of upward continuous casting to obtain an alloy cast rod, directly carrying out cold drawing deformation with the total deformation amount of 75% -85% on the cast rod, and then carrying out abnormal hardening annealing at 240-260 ℃ for 30-120 minutes. The alloy prepared by the invention has a unique abnormal hardening effect that the hardness after annealing is higher than that of a cold drawing state, the Vickers hardness of the alloy is improved by 1.2% -10.0% compared with that of the cold drawing state, and meanwhile, the conductivity of the alloy is kept above 97% IACS. The method has the advantages of simple process, low energy consumption and obvious cost benefit, and the obtained alloy has the comprehensive performance similar to that of the traditional Cu-0.08Ag alloy, and can be used for replacing the latter to be used for precise conductive structural members such as high-end connectors, lead frames, commutators and the like.

Inventors

  • YANG WEILIANG
  • HUANG HAO
  • XU HENGLEI

Assignees

  • 江西康成特导新材股份有限公司

Dates

Publication Date
20260505
Application Date
20260209

Claims (10)

  1. 1. The preparation method of the Cu-Ag-Sn copper alloy is characterized by comprising the following chemical components, by mass, 0.03% -0.05% of Ag, 0.005% -0.05% of Sn, less than or equal to 0.01% of unavoidable impurities and the balance of Cu, wherein the preparation method comprises the following steps of: (1) Performing upward continuous casting, namely taking copper, silver particles and tin particles as raw materials, and obtaining a Cu-Ag-Sn alloy cast rod by adopting an upward continuous casting method; (2) Direct cold drawing deformation, namely directly carrying out 2-8 times of cold drawing deformation on the alloy cast rod obtained in the step (1) without any intermediate heat treatment, wherein the total deformation is 75% -85%, and obtaining a cold drawing state wire rod or bar; (3) And (3) carrying out abnormal hardening annealing, namely annealing the cold-drawn material obtained in the step (2) at 240-260 ℃ for 30-120 minutes, and then quenching and water cooling to room temperature.
  2. 2. The method according to claim 1, wherein in the step (1), the casting temperature of the upward continuous casting is 1135 to 1165 ℃, and the pitch of the casting bar is 2 to 5mm.
  3. 3. The method according to claim 1, wherein in the step (1), the upward continuous casting speed is 700-900mm/min when the diameter of the copper rod is 12mm, the upward continuous casting speed is 500-630mm/min when the diameter of the copper rod is 15-18mm, and the upward continuous casting speed is 350-400mm/min when the diameter of the copper rod is 20 mm.
  4. 4. The method according to claim 1, wherein in the step (2), the total deformation amount is 75% -85%.
  5. 5. The method according to claim 1, wherein in the step (3), the annealing temperature is 248-252 ℃ and the holding time is 50-70 minutes.
  6. 6. The method according to claim 1, wherein the "without any intermediate heat treatment" in the step (2) means that, after the up-casting step, heat treatment for changing the microstructure or solute distribution of the material is not applied to the material before the abnormal-hardening annealing step, including no homogenization heat treatment and no solution heat treatment.
  7. 7. A high strength, high conductivity Cu-Ag-Sn copper alloy material made by the method of any one of claims 1 to 6.
  8. 8. The Cu-Ag-Sn copper alloy material of claim 7 wherein the alloy material has a conductivity of no less than 97% IACS.
  9. 9. The Cu-Ag-Sn copper alloy material of claim 7 or 8, wherein the alloy composition is Cu-0.05Ag-0.03Sn.
  10. 10. The alloy material according to claim 9, wherein the HV hardness of the alloy material is above 124.

Description

Short-process preparation method of high-strength high-conductivity Cu-Ag-Sn copper alloy Technical Field The invention relates to the technical field of high-performance copper alloy materials, in particular to an ultra-short flow preparation method of a high-strength high-conductivity Cu-Ag-Sn copper alloy capable of replacing the traditional Cu-Ag alloy. Background The high-strength high-conductivity copper alloy is an indispensable key base material in the fields of electronics and electricity, new energy automobiles, high-end communication and the like. Among them, silver-containing copper alloy (e.g., cu-0.08 Ag) is widely used for precision parts such as commutators, lead frames, connectors, etc., due to its good electrical conductivity and improved strength. However, silver is used as noble metal, the addition of the silver obviously increases the material cost, and silver resources in China are relatively deficient. Therefore, the development of new copper alloys that can reduce silver content while maintaining or improving overall properties is an urgent need in the industry. The preparation of traditional high-performance copper alloys (such as Cu-Cr-Zr, cu-Ni-Si, cu-Fe and the like) generally depends on complex thermomechanical treatment processes, including lengthy steps of homogenizing annealing, solution treatment, cold deformation, aging and the like, so as to regulate and control precipitated phases to obtain strengthening. The pretreatment procedures have high energy consumption, long flow and high cost. For microalloying systems, homogenization and solution treatment are further considered essential steps to obtain supersaturated solid solutions of uniform composition. Furthermore, in conventional wisdom, low temperature annealing after cold deformation typically results in reversion or even recrystallization of the material, resulting in a decrease in strength, hardness (softening) in exchange for plastic and conductive recovery. How to realize breakthrough of performance, especially to find new performance evolution rules while simplifying the flow is a great challenge for the person skilled in the art. Disclosure of Invention The invention aims to overcome the defects of the prior art and provide a short-flow preparation method of a high-strength high-conductivity Cu-Ag-Sn copper alloy. The alloy is subjected to microalloying by using extremely low Ag and Sn, and on the premise of completely omitting homogenization and solution treatment, the special process not only realizes the performance substitution and exceeding of the traditional Cu-0.08Ag alloy, but also discovers the unique phenomenon of abnormal rise of hardness after low-temperature annealing in the system for the first time, thereby obtaining the novel copper alloy material with extremely simple flow, lower cost and better comprehensive performance. In order to achieve the above purpose, the invention adopts the following technical scheme: in a first aspect, the invention provides a short-process preparation method of a high-strength high-conductivity Cu-Ag-Sn copper alloy, which comprises the following chemical components in percentage by mass: (1) Performing upward continuous casting, namely taking copper, silver particles and tin particles as raw materials, and obtaining a Cu-Ag-Sn alloy cast rod by adopting an upward continuous casting method; (2) Direct cold drawing deformation, namely directly carrying out 2-X-pass cold drawing deformation on the alloy cast rod obtained in the step (1) without any intermediate heat treatment, wherein the reduction of area is 75% -85%, and obtaining a cold drawing state wire rod or bar; (3) And (3) annealing the cold-drawn material obtained in the step (2) at 240-260 ℃ for 30-120 minutes, and then air cooling or water cooling. Preferably, the casting temperature in step (1) is 1135-1165 ℃. Preferably, the pitch of the upward continuous casting bar in the step (1) is 2-5mm. Preferably, the upward continuous casting speed in the step (1) is 700-900mm/min when the diameter of the copper rod is 12mm, 500-630mm/min when the diameter of the copper rod is 15-18mm, and 350-400mm/min when the diameter of the copper rod is 20 mm. Preferably, the area reduction rate in the step (2) is 80-85%. Preferably, in the step (3), the annealing temperature is 248-252 ℃ and the heat preservation time is 50-70 minutes. In a second aspect, the present invention provides a high-strength high-conductivity Cu-Ag-Sn copper alloy material prepared by the above method, which has a hardness after annealing in step (3) higher than that in a cold drawn state after completion of step (2), and has a conductivity of not less than 97% IACS. The invention has the beneficial effects that: (1) The composite micro-alloying of Ag and Sn has the advantages of novel component design and obvious cost advantage, the total addition amount is extremely low (less than or equal to 0.1 percent), the consumption of expensive metal silve