Copper-aluminum composite plate strip and production method

Abstract

The present application relates to copper-aluminum composite plate strip technical field, especially a kind of copper-aluminum composite plate strip and production method, it is made of aluminum material and copper material composite, the oxygen content of copper material is 50ppm-500ppm, production method includes oxygen-increasing treatment to red copper or oxygen-free copper, the present application reduces the recrystallization temperature of copper material by increasing the oxygen content in copper material, in turn reduces annealing temperature, copper-aluminum composite blank heat treatment below 300 DEG C can satisfy copper material complete recrystallization, realize soft annealing, meet the demand of bending, while reducing the thickness of copper-aluminum intermetallic compound in heat treatment process, improve the composite strength of copper-aluminum composite plate strip.

Description

Technical Field

[0001] This invention relates to the field of copper-aluminum composite strip technology, and in particular to a copper-aluminum composite strip and its production method. Background Technology

[0002] Existing copper-aluminum composite sheets and strips present a challenge in matching bending performance with composite strength. To meet the bending requirements of copper-aluminum composite sheets and strips, the copper surface needs to be soft, have good toughness, high elongation, and a high annealing temperature, currently around 300℃. However, when the annealing temperature of copper-aluminum composite sheets and strips exceeds 250℃, the amount of intermetallic compounds between copper and aluminum increases, and this increase becomes rapid above 300℃, resulting in an intermetallic compound thickness exceeding 2μm. The recrystallization temperature range for copper is 200-280℃, and to achieve sufficient recrystallization of copper, the recrystallization annealing temperature is generally controlled between 380-680℃. Therefore, there is a contradiction between maintaining a stable recrystallization temperature range for copper and meeting the upper temperature limit required for the composite strength of copper-aluminum.

[0003] Patent CN103060624B discloses aluminum materials, copper-aluminum composite strips, and processing methods for copper-aluminum composite sheets and strips. The copper-aluminum composite strip consists of an aluminum base layer and a copper cladding layer. The processing steps include forming a billet through oxygen-free high-pressure continuous casting and rolling, followed by cold rolling, intermediate annealing, precision rolling, and final annealing. The intermediate annealing temperature in the aforementioned technology is 200-400℃. However, when the annealing temperature of the copper-aluminum composite strip exceeds 250℃, the amount of intermetallic compounds between copper and aluminum increases, and increases sharply above 300℃, resulting in an intermetallic compound thickness exceeding 2μm and a decrease in composite strength.

[0004] Therefore, there is an urgent need for a copper-aluminum composite sheet / strip that can simultaneously meet the requirements of bending performance and composite strength. Summary of the Invention

[0005] To overcome the shortcomings of the prior art, the present invention provides a copper-aluminum composite plate and strip and a production method thereof.

[0006] The technical solution adopted by this invention to solve its technical problem is:

[0007] A copper-aluminum composite plate and strip, composed of aluminum and copper materials, is characterized in that the oxygen content of the copper material is 50ppm-500ppm.

[0008] Preferably, the oxygen content of the copper material is 50 ppm.

[0009] Preferably, the oxygen content of the copper material is 120 ppm.

[0010] Preferably, the oxygen content of the copper material is 500 ppm.

[0011] A method for producing the aforementioned copper-aluminum composite sheet and strip comprises the following steps:

[0012] (1) Oxygenating copper or oxygen-free copper is performed to make the oxygen content of copper or oxygen-free copper 50ppm-500ppm, and copper material is obtained.

[0013] (2) Melt aluminum ingots at 700-850℃, then add Si, Fe, Cu and Mn to melt, refine and degas, let the refined and degassed molten liquid stand at 690-820℃ for 5-15 minutes, and then pour it into a preheated casting nozzle. The cast aluminum alloy liquid is cooled and crystallized to a semi-molten state to obtain semi-molten aluminum material.

[0014] (3) After the copper material in step (1) is degreased by alkaline washing, it is then polished on one side until there is no oxide layer on the surface. After polishing, the copper material is heated to 230-250℃.

[0015] (4) The semi-molten aluminum material in step (2) and the polished surface of the copper material in step (3) are brought into contact and subjected to oxygen-free high-pressure continuous casting and rolling to obtain copper-aluminum composite billet.

[0016] (5) The copper-aluminum composite billet from step (4) is subjected to cold rolling, and the total processing rate of cold rolling is 15-75%.

[0017] (6) The copper-aluminum composite billet after cold rolling in step (5) is subjected to periodic nitrogen-protected bellows furnace annealing treatment. The room temperature is raised to 170-190℃, the oil is removed by blowing for 1.5-2.5 hours, the annealing temperature is 200-300℃, the holding temperature is 3-8 hours, and the furnace is rapidly cooled to below 65℃ before being taken out of the furnace.

[0018] The beneficial effects of this invention are: by increasing the oxygen content in the copper material, the recrystallization temperature of the copper material is reduced, thereby reducing the annealing temperature. The copper-aluminum composite billet can be heat-treated at a temperature below 300°C to meet the requirements of complete recrystallization of the copper material, achieve soft annealing, meet the bending requirements, and at the same time reduce the thickness of the intermetallic compound between copper and aluminum during the heat treatment process, thereby improving the composite strength of the copper-aluminum composite plate and strip. Attached Figure Description

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0020] Figure 1 This is a thickness diagram of the intermetallic compound from Example 1;

[0021] Figure 2 This is a thickness diagram of the intermetallic compound from Example 2;

[0022] Figure 3 This is a thickness diagram of the intermetallic compound from Example 3;

[0023] Figure 4 This is a thickness diagram of the intermetallic compound from Example 4;

[0024] Figure 5 This is a thickness diagram of the intermetallic compound from Example 5;

[0025] Figure 6 This is a thickness diagram of the intermetallic compound from Example 6;

[0026] Figure 7 This is a thickness diagram of the intermetallic compound from Example 7;

[0027] Figure 8 This is a thickness diagram of an intermetallic compound, as shown in Comparative Example 1.

[0028] Figure 9 This is a thickness diagram of the intermetallic compound in Comparative Example 2;

[0029] Figure 10 This is a thickness diagram of a trimetallic intermetallic compound, as shown in the comparative example.

[0030] Figure 11 This is a thickness diagram of intermetallic compounds in Comparative Example 4;

[0031] Figure 12 This is a thickness diagram of intermetallic compounds in Comparative Example 5;

[0032] Figure 13 This is a thickness diagram of intermetallic compounds in Comparative Example Six;

[0033] Figure 14 This is a thickness diagram of intermetallic compounds in Comparative Example 7;

[0034] Figure 15 This is a thickness diagram of intermetallic compounds in Comparative Example 8. Detailed Implementation

[0035] In all embodiments of the present invention, unless otherwise emphasized, temperature and pressure are at normal temperature and pressure. Unless otherwise specified, the equipment can be used according to conventional settings.

[0036] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other.

[0037] Combination Figures 1 to 15 :

[0038] Example 1: As Figure 1 As shown, a copper-aluminum composite strip is made of aluminum and copper materials. The oxygen content of the copper material is 120 ppm, and the copper material is made of T2 copper through an oxygenation treatment.

[0039] Preparation method:

[0040] (1) T2 copper is subjected to oxygenation treatment so that the oxygen content of T2 copper is 120ppm, and copper material is obtained (the oxygenation treatment method may be, but is not limited to, the oxygenation method disclosed in CN116162817A).

[0041] (2) Melt aluminum ingots at 700°C, then add Si, Fe, Cu and Mn to melt, refine and degas, let the refined and degassed molten liquid stand at 790°C for 5 minutes, and then pour it into a preheated casting nozzle. The cast aluminum alloy liquid is cooled and crystallized to a semi-molten state to obtain semi-molten aluminum material.

[0042] (3) After the copper material in step (1) is degreased by alkaline washing, it is then polished on one side until there is no oxide layer on the surface. After polishing, the copper material is heated to 230°C.

[0043] (4) The semi-molten aluminum material from step (2) is brought into contact with the polished surface of the copper material from step (3), and oxygen-free high-pressure continuous casting and rolling is performed. The rolling speed is 0.5 m / s and the rolling pressure is 12 × 10⁻⁶ m / s. 6 N, to obtain a 6.5mm copper-aluminum composite billet.

[0044] (5) The copper-aluminum composite billet from step (4) is subjected to cold rolling at a rolling speed of 0.5 m / s and a rolling pressure of 20 × 10⁻⁶ m / s. 6 N, tension is 5×10 6 N, with a per-pass processing rate of 10-30% and a total processing rate of 60%.

[0045] (6) The copper-aluminum composite billet after cold rolling in step (5) is subjected to periodic nitrogen protection furnace annealing treatment. The room temperature is raised to 180°C, the oil is removed by blowing for 2 hours, the annealing temperature is 250°C, the holding temperature is 5 hours, and the furnace is rapidly cooled to below 60°C before being taken out of the furnace to obtain a finished product with a thickness of 4mm.

[0046] Example 2: Figure 2 As shown, the difference from Example 1 is that the thickness of the finished product in step (6) is 3mm.

[0047] Example 3: Figure 3 As shown, the difference from Example 1 is that the annealing temperature in step (6) is 200°C.

[0048] Example 4: Figure 4 As shown, the difference from Example 2 is that the annealing temperature in step (6) is 200°C.

[0049] Example 5: Figure 5As shown, the difference from Example 1 is that: the oxygen content of the copper material is 180ppm; the oxygen content of T2 copper in step (1) is 180ppm; the thickness of the composite billet in step (3) is 8mm; and the annealing temperature in step (6) is 230℃.

[0050] Example 6: Figure 6 As shown, the difference from Example 5 is that the thickness of the finished product in step (6) is 3mm.

[0051] Example 7: Figure 7 As shown, the difference from Example 5 is that the annealing temperature in step (6) is 200°C.

[0052] Example 8: The difference from Example 1 is that the oxygen content of the copper material is 50 ppm; the oxygen content of the T2 copper in step (1) is 50 ppm; the annealing temperature in step (6) is 210℃, and the holding time is 5 hours. The interface thickness was measured to be 600 nm, and the peel strength was 28 N / mm.

[0053] Example 9: The difference from Example 1 is that the oxygen content of the copper material is 500 ppm; the oxygen content of the T2 copper in step (1) is 500 ppm; the annealing temperature in step (6) is 250℃, and the holding time is 5 hours. The interface thickness was measured to be 650 nm, and the peel strength was 30 N / mm.

[0054] Example 10: The difference from Example 1 is that the oxygen content of the copper material is 60 ppm; the oxygen content of the T2 copper in step (1) is 60 ppm; the thickness of the composite blank in step (3) is 8 mm; and the heat preservation time in step (6) is 8 hours. The interface thickness was measured to be 600 nm and the peel strength was 30 N / mm.

[0055] Example 11: The difference from Example 1 is that the composite blank thickness in step (3) is 7 mm; the annealing temperature in step (6) is 240℃, the holding time is 6 hours, and the thickness of the finished product is 5 mm. The interface thickness was measured to be 500 nm and the peel strength was 35 N / mm.

[0056] Example 12: The difference from Example 1 is that the oxygen content of the copper material is 200 ppm; the oxygen content of the T2 copper in step (1) is 200 ppm; the thickness of the composite billet in step (3) is 8 mm; the annealing temperature in step (6) is 220℃, the holding time is 3 hours, and the thickness of the finished product is 3 mm. The interface thickness was measured to be 500 nm, and the peel strength was 25 N / mm.

[0057] Example 13: The difference from Example 1 is that the oxygen content of the copper material is 300 ppm; the oxygen content of the T2 copper in step (1) is 300 ppm; the thickness of the composite billet in step (3) is 8 mm; the annealing temperature in step (6) is 270℃, and the thickness of the finished product is 6 mm. The interface thickness was measured to be 700 nm, and the peel strength was 28 N / mm.

[0058] Comparative Example 1: Figure 8 As shown, a copper-aluminum composite strip is made of aluminum and copper, wherein the copper is T2 copper.

[0059] Preparation method:

[0060] (1) Melt aluminum ingots at 700℃, then add Si, Fe, Cu and Mn to melt, refine and degas, let the refined and degassed molten liquid stand at 790℃ for 5 minutes, and then pour it into a preheated casting nozzle. The cast aluminum alloy liquid is cooled and crystallized to a semi-molten state to obtain semi-molten aluminum material.

[0061] (2) After the copper material is degreased by alkaline washing, it is then polished on one side until there is no oxide layer on the surface. After polishing, the copper material is heated to 230°C.

[0062] (3) The semi-molten aluminum material from step (1) and the polished surface of the copper material from step (2) are brought into contact and subjected to oxygen-free high-pressure continuous casting and rolling at a rolling speed of 0.5 m / s and a rolling pressure of 12 × 10⁻⁶ m / s. 6 N, to obtain a 6.5mm copper-aluminum composite billet.

[0063] (4) The copper-aluminum composite billet from step (3) is subjected to cold rolling at a rolling speed of 0.5 m / s and a rolling pressure of 20 × 10⁻⁶ m / s. 6 N, tension is 5×10 6 N, with a per-pass processing rate of 10-30% and a total processing rate of 60%.

[0064] (5) The copper-aluminum composite billet after cold rolling in step (4) is subjected to periodic nitrogen protection furnace annealing treatment. The room temperature is raised to 180°C, the oil is removed by blowing for 2 hours, the annealing temperature is 250°C, the holding temperature is 5 hours, and the furnace is rapidly cooled to below 60°C before being taken out of the furnace to obtain a finished product with a thickness of 4mm.

[0065] Comparative Example 2: Figure 9 As shown, the difference from Comparative Example 1 is that the thickness of the finished product in step (5) is 3mm.

[0066] Comparative Example 3: Figure 10 As shown, the difference from Comparative Example 1 is that the annealing temperature in step (5) is 315℃ and the holding time is 8 hours.

[0067] Comparative Example 4: Figure 11 As shown, the difference from Comparative Example 3 is that the thickness of the finished product in step (5) is 3mm.

[0068] Comparative Example 5: Figure 12 As shown, the difference from Comparative Example 3 is that the thickness of the composite blank in step (3) is 8 mm.

[0069] Comparative Example 6: Figure 13 As shown, the difference from Comparative Example 5 is that the thickness of the finished product in step (5) is 3mm.

[0070] Comparative Example 7: Figure 14 As shown, the difference from Comparative Example 1 is that the thickness of the composite blank in step (3) is 8 mm; and the annealing temperature in step (5) is 230℃.

[0071] Comparative Example 8: Figure 15 As shown, the difference from Comparative Example 7 is that the thickness of the finished product in step (5) is 3 mm.

[0072] Performance tests were performed on Examples 1 to 7 and all comparative examples, as detailed in the table below:

[0073]

[0074]

[0075]

[0076] The data above clearly demonstrates that, compared to traditional oxygen-free copper, this invention increases the oxygen content in the copper material, thereby reducing the recrystallization temperature and consequently lowering the annealing temperature during heat treatment. Heat treatment below 300℃ is sufficient to achieve complete recrystallization of the copper. The low annealing temperature results in low energy consumption, stable processing, and soft annealing, meeting bending requirements. Simultaneously, it reduces the thickness of the intermetallic compound between copper and aluminum during heat treatment, controlling the copper-aluminum composite interface layer to below 1μm, thus increasing the composite strength of the copper-aluminum composite strip from the traditional 12N / mm to over 20N / mm.

[0077] The above embodiments do not limit the scope of protection of this invention. Various changes and modifications can be made to this invention without departing from the spirit and scope of this invention, and all such changes and modifications fall within the scope of this invention as claimed.

Claims

1. A method for producing copper-aluminum composite plates and strips, characterized in that, It is composed of aluminum and copper materials, wherein the oxygen content of the copper material is 120ppm-180ppm, and the steps are as follows: (1) Oxygenating copper or oxygen-free copper to make the oxygen content of copper or oxygen-free copper 120ppm-180ppm, and then producing copper material. (2) Melt aluminum ingots at 700-850℃, then add Si, Fe, Cu and Mn to melt, refine and degas, let the refined and degassed molten liquid stand at 690-820℃ for 5-15 minutes, and then pour it into a preheated casting nozzle. The cast aluminum alloy liquid is cooled and crystallized to a semi-molten state to obtain semi-molten aluminum material. (3) After the copper material in step (1) is degreased by alkaline washing, it is then polished on one side until there is no oxide layer on the surface. After polishing, the copper material is heated to 230-250℃. (4) The semi-molten aluminum material in step (2) and the polished surface of the copper material in step (3) are brought into contact and subjected to oxygen-free high-pressure continuous casting and rolling to obtain copper-aluminum composite billet. (5) The copper-aluminum composite billet from step (4) is subjected to cold rolling, and the total processing rate of the cold rolling is 15-75%. (6) The copper-aluminum composite billet after cold rolling in step (5) is subjected to periodic nitrogen protection furnace annealing treatment. The room temperature is raised to 170-190℃, the oil is removed by blowing for 1.5-2.5 hours, the annealing temperature is 200-300℃, the holding temperature is 3-8 hours, and the furnace is rapidly cooled to below 65℃ before being taken out of the furnace.

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