Copper alloy material and preparation process thereof

Abstract

The invention discloses a copper alloy material and a preparation process thereof, and belongs to the technical field of copper alloy preparation, and the copper alloy material comprises the following components in percentage by mass: 0.7-0.9% of nickel, 1.0-2.0% of tin, 0.02-0.09% of phosphorus and the balance of copper. The preparation process comprises the following steps that copper, nickel, tin and copper-phosphorus alloy are sequentially added according to the mass proportion; after all the components are added, smelting at the temperature of 1080-1200 DEG C and standing in a heat preservation furnace are conducted in sequence, and molten liquid is obtained; and after standing, the molten liquid is subjected to semi-continuous vibration casting, and a cast ingot is obtained. The content of each element of the copper alloy material is stable, the structure of a cast ingot is uniform, and the phenomena of segregation and uneven components are avoided. In the subsequent machining process, peeling and hole phenomena caused by uneven structures and segregation components do not occur on the surface of the strip.

Description

Technical Field

[0001] The present invention relates to the technical field of copper alloy preparation, and in particular to a copper alloy material and a preparation process thereof. Background Art

[0002] Copper alloys (such as Cu-Ni-Sn-P) have many advantages such as high strength, high hardness, high elasticity, strong resistance to thermal stress relaxation, stable conductivity, solderability, plating, non-toxic and environmentally friendly, etc., and are widely used in lead frames, micro terminals, elastic components and other fields. Cu-Ni-Sn-P alloy mainly adds three elements, Ni, Sn and P, to copper. Since the copper alloy contains both high melting point element nickel and low melting point element tin, alloy component segregation and uneven structure will occur during the smelting process, causing cracks, pores, inclusions and other phenomena in the ingot; during the subsequent processing of the ingot into high-precision Cu-Ni-Sn-P alloy strip products, defects such as peeling and slag (small copper chips) will occur; after the Cu-Ni-Sn-P alloy is rolled to a certain extent, holes and broken strips may even appear, affecting the quality of the Cu-Ni-Sn-P alloy strip products. Summary of the invention

[0003] In view of the above technical problems still existing in the prior art, the present invention provides a copper alloy material and a preparation process thereof, which solves the problem of component segregation during ingot casting of the copper alloy material.

[0004] The present invention discloses a first aspect of providing a preparation process of a copper alloy material, wherein the copper alloy material comprises the following components in mass percentage: 0.7-0.9% nickel, 1.0-2.0% tin, 0.02-0.09% phosphorus, and the remainder is Cu; the preparation process comprises the following steps: adding copper, nickel, tin and copper-phosphorus alloy in sequence according to the mass ratio; after adding each component, smelting at 1080-1200°C in sequence and standing in a holding furnace to obtain a molten liquid; after standing, performing semi-continuous vibration casting on the molten liquid to obtain an ingot.

[0005] Preferably, nickel is added when the smelting temperature reaches above 1100° C., and copper has melted when nickel is added.

[0006] Preferably, the Cu content exceeds 97%.

[0007] Preferably, the smelting is carried out in a medium frequency induction melting furnace, and after the smelting, the smelting is carried out by converting the smelting furnace to a holding furnace at 1130-1250°C.

[0008] Preferably, the standing time in the holding furnace exceeds 12 minutes.

[0009] Preferably, a power frequency cored holding furnace and an integral crystallizer are used for semi-continuous vibration casting, with a vibration frequency of 50-80 times / min; a casting temperature of 1130-1200° C., and a casting speed of 50-80 mm / min.

[0010] Preferably, the overall crystallizer has a size of 175 mm × 430 mm × 300 mm and a cooling water flow rate of 25-40 m 3 / h.

[0011] Preferably, the ingot is further processed to obtain subsequent products such as strips and copper alloy frames.

[0012] A second aspect of the present invention provides a copper alloy material prepared by the above preparation process.

[0013] Preferably, the copper alloy material is in the form of an ingot, a strip and a frame.

[0014] Compared with the prior art, the invention has the following beneficial effects: the content of each element in the copper alloy material is stable, the ingot structure is uniform, and there is no segregation or uneven composition. In the subsequent processing, there is no peeling or hole phenomenon on the strip surface caused by uneven structure and segregated components. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a process flow chart of the preparation of the copper alloy material of the present invention;

[0016] Figure 2 It is a schematic diagram of an ingot of an existing copper alloy material;

[0017] Figure 3 It is a partial schematic diagram of an ingot of an existing copper alloy material;

[0018] Figure 4 is a graph showing the ingot detection results of Example 1;

[0019] Figure 5 This is a graph of the ingot inspection results of Example 2. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0022] like Figure 1 The preparation process of the copper alloy material of the present invention comprises the following steps:

[0023] Step S1: preparing ingredients.

[0024] The mass percentage of each component is: Ni 0.7-0.9%, Sn 1.0-2.0%, P 0.02-0.09%, and the balance is copper Cu. The content of copper exceeds 97%, and the copper alloy material contains inevitable impurities.

[0025] Step S2: feeding.

[0026] Standard electrolytic copper, nickel, tin and phosphorus (copper-phosphorus alloy) are added in sequence according to the mass ratio. The timing of adding nickel is when the melting temperature reaches above 1100°C. The phosphorus content in the copper-phosphorus alloy is 5-15%. The introduction of P through the copper-phosphorus alloy improves the addition efficiency.

[0027] Step S3: smelting.

[0028] Melting at 1080-1200℃. Using medium frequency induction melting furnace, after nickel is added, let it stand for more than 50 minutes before sampling and analysis.

[0029] Step S4: Convert the furnace to a holding furnace at a temperature of 1130-1250°C.

[0030] Step S5: The holding furnace is left to stand.

[0031] The standing time is ≥12min, and the furnace temperature is 1130-1200℃. Pay attention to control the content ratio of Ni, P, Sn and other elements according to the sampling analysis results.

[0032] Step S6: Casting.

[0033] The semi-continuous vibration casting is carried out using a power frequency cored holding furnace and an integral crystallizer, the crystallizer specification is 175mm×430mm×300mm. The vibration frequency is 50-80 times / min; the casting temperature is 1130-1200℃, the casting speed is 50-80mm / min, and the cooling water flow rate is 25-40m 3 / h.

[0034] Step S7: performing subsequent processing on the ingot, such as sawing, stretching, etc.

[0035] The content of each element in the copper alloy material is stable, the ingot structure is uniform, and there is no segregation or uneven composition. In the subsequent processing, there is no peeling or hole on the strip surface caused by uneven structure and segregated components.

[0036] The present invention arranges the feeding sequence reasonably according to the characteristics of metal elements added in the alloy. Ni has a high melting point and is not easy to melt, and is easy to absorb air, resulting in defects such as pores. After the copper is melted, nickel is added to the copper liquid, and then tin is added to give full play to the best performance of the alloy. Since Sn has a low melting point and is easy to reverse segregate, a suitable furnace type should be selected in the casting process, the relationship between the casting speed and the cooling intensity should be well controlled, and a stop-pull + vibration casting method is adopted to reduce dendrite segregation, improve the surface quality of the ingot, reduce ingot cracks and scars, and prevent the ingot segregation from affecting subsequent processing.

[0037] During the melting and casting process, Ni is easy to absorb air, and bubbles exist in the matrix. When it comes to the finished product stage, stratification will occur, causing quality risks. Therefore, sufficient standing time is required during casting to facilitate sufficient exhaust. Since the presence of low-melting-point Sn is prone to segregation and thermal cracking, it is necessary to reasonably control the cooling intensity and casting speed to reduce subcutaneous cracking. When selecting a specific furnace type, the relationship between speed and cooling should be controlled during the casting process. A casting method with a certain frequency of vibration should be used to reduce dendrite segregation, subcutaneous cracking, looseness and surface scarring of the ingot. Sufficient standing time is given during the casting process to prevent the melt from inhaling air.

[0038] Example 1

[0039] The cost ratio is: Ni: 0.89%, Sn: 1.6%, P: 0.07%, Cu: 97.1%. Standard electrolytic copper, nickel, tin and copper-phosphorus alloy are added in order according to the mass ratio. Among them, the timing of adding nickel is when the melting temperature is 1100℃; the phosphorus content in the copper-phosphorus alloy is 5%. Melting temperature 1080-1130℃. Converter temperature 1130-1180℃. The holding furnace is left standing for ≥20min, and the furnace temperature is 1130-1160℃. Casting temperature 1130-1160℃, casting speed 72mm / min, cooling water flow 32-35m 3 / h, the trolley vibration frequency is 70 times / min, and ingot 1 is obtained. The content of each element in ingot 1 is stable, the structure is uniform, and there is no segregation or uneven composition; there is no subcutaneous crack defect. During subsequent processing, no peeling or holes caused by uneven structure and segregated components appear on the surface of the strip.

[0040] Example 2

[0041] Composition ratio: Ni: 0.75%, Sn: 1.1%, P: 0.05%, Cu: 97.8%. Add standard electrolytic copper, nickel, tin and copper-phosphorus alloy in order according to the mass ratio. The timing of adding nickel is when the melting temperature is 1105℃. Melting temperature 1130-1180℃. Converter temperature 1180-1230℃. Let the holding furnace stand for ≥12min, and the furnace temperature is 1170-1200℃. Casting temperature 1170-1200℃, casting speed 58mm / min, cooling water flow 26-29m 3 / h, the trolley vibration frequency is 60 times / min, and ingot 2 is obtained. The content of each element in ingot 2 is stable, the structure is uniform, and there is no segregation or uneven composition; there is no subcutaneous crack defect. During subsequent processing, there is no peeling or hole phenomenon caused by uneven structure and segregation components on the surface of the strip.

[0042] Example 3

[0043] Composition ratio: Ni: 0.81%, Sn: 1.3%, P: 0.06%, Cu: 97.6%. Add standard electrolytic copper, nickel, tin and copper-phosphorus alloy in order according to the mass ratio. The timing of adding nickel is when the melting temperature is 1110℃. Melting temperature 1080-1200℃. Converter temperature 1130-1250℃. Standing time ≥12min, furnace temperature 1130-1200℃. Casting temperature 1130-1200℃, casting speed 50-80mm / min, cooling water flow 25-40m 3 / h; vibration frequency 50-80 times / min, to obtain ingot 3. Ingot 3 has stable composition and uniform structure, no segregation, uneven composition, and no subcutaneous crack defects. During subsequent processing, there is no peeling or hole on the surface of the strip.

[0044] Figure 2 and Figure 3 It shows that the existing copper alloy ingots have uneven composition. Figure 4 and Figure 5 The inspection results of ingot 1 and ingot 2 are shown, and the composition is stable, the structure is uniform, there is no segregation, and the composition is uneven; there is no subcutaneous crack defect.

[0045] In the copper alloy material of the present invention, according to the contents of the three elements Ni, Sn and P in the ASTM standard and the Cu-Ni, Cu-Sn and Cu-P phase diagrams, the added elements Ni and P both form a solid solution α body with Cu; at 200°C, the solubility of Sn in copper is 1.3%, so there is a second phase in the non-equilibrium crystallization structure. The surface quality of the obtained ingot has no defects such as cracks, scars, cold shuts, etc., and the internal structure is uniform and dense, without cracks, pores, slag inclusions, etc.

[0046] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A process for preparing a copper alloy material, characterized in that: The copper alloy material includes the following components in mass percentage: 0.7-0.9% nickel, 1.0-2.0% tin, 0.02-0.09% phosphorus, and the balance is copper; the preparation process includes the following steps: According to the mass percentage, copper, nickel, tin and copper-phosphorus alloy are added in sequence; After adding, smelting at 1080-1200℃ and standing in a holding furnace to obtain a melt; After standing, the melt is subjected to semi-continuous vibration casting to obtain an ingot.

2. The preparation process according to claim 1, characterized in that: The timing for adding nickel is when the melting temperature reaches above 1100°C.

3. The preparation process according to claim 1, characterized in that: The copper content is over 97%.

4. The preparation process according to claim 1, characterized in that: It is melted in a medium frequency induction melting furnace, and after melting, it is transferred to a holding furnace at 1130-1250℃.

5. The preparation process according to claim 1, characterized in that: The standing time in the holding oven is more than 12 minutes.

6. The preparation process according to claim 1, characterized in that: A power frequency cored holding furnace and an integral crystallizer are used for semi-continuous vibration casting, with a vibration frequency of 50-80 times / min; a casting temperature of 1130-1200°C, and a casting speed of 50-80mm / min.

7. The preparation process according to claim 6, characterized in that: The overall crystallizer specifications are 175mm×430mm×300mm, and the cooling water flow rate is 25-40m 3 / h.

8. The preparation process according to claim 1, characterized in that: The ingot is then subjected to subsequent processing.

9. A copper alloy material, characterized in that: Prepared by the preparation process described in any one of claims 1 to 8.

10. The copper alloy material according to claim 9, characterized in that: The copper alloy material has any of the following forms: ingot, strip and frame.

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