Preparation method of copper-chromium-silicon-titanium alloy and copper-chromium-silicon-titanium alloy wire

Abstract

This invention discloses a method for preparing copper-chromium-silicon-titanium alloy and copper-chromium-silicon-titanium alloy wire, relating to the field of non-ferrous metal preparation technology. The method for preparing the copper-chromium-silicon-titanium alloy includes the following steps: melting, melting raw materials including copper, chromium, silicon, and titanium to obtain a melt; continuous casting, continuously casting a copper-chromium-silicon-titanium alloy billet under an inert gas atmosphere; drawing, drawing the copper-chromium-silicon-titanium alloy billet to form a wire; aging treatment, aging the wire under an inert gas atmosphere and cooling it in a furnace to obtain the copper-chromium-silicon-titanium alloy wire, wherein the aging treatment temperature is 400℃~500℃ and the time is 1~3h. The copper-chromium-silicon-titanium alloy prepared by this invention has a fibrous crystalline structure. Due to the low impurity content between the fibrous grain boundaries, the probability of recrystallization nucleation is low. During the aging treatment, the probability of grain boundaries acting as nucleation sites is significantly reduced, thereby increasing the recrystallization temperature of the alloy and improving the stress relaxation resistance of the copper-chromium-silicon-titanium alloy.

Description

Technical Field

[0001] This invention relates to the field of non-ferrous metal preparation technology, and more specifically, to a method for preparing copper-chromium-silicon-titanium alloys and copper-chromium-silicon-titanium alloy wires. Background Technology

[0002] With the rapid development of fields such as electronic communications, transportation, and aerospace, the demand for copper alloy materials in connectors is increasing, and higher performance requirements are being placed on them. Not only are high strength and high conductivity required, but excellent resistance to stress relaxation is also necessary. Stress relaxation is a special deformation process in which elastic strain continuously transforms into plastic strain under the combined effects of thermal activation and stress, and it is a major factor leading to unstable contact resistance in connectors.

[0003] Copper-chromium-silicon-titanium alloys possess advantages such as high strength and high conductivity, making them promising candidates for connector applications. However, copper-chromium-silicon-titanium alloys prepared using conventional casting, extrusion, and drawing methods exhibit poor stress relaxation resistance, significantly limiting their widespread application. Therefore, it is essential to research and develop a method for preparing copper-chromium-silicon-titanium alloys with high stress relaxation resistance.

[0004] In view of this, the present invention is proposed. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing copper-chromium-silicon-titanium alloy and copper-chromium-silicon-titanium alloy wire, thereby improving the stress relaxation resistance of copper-chromium-silicon-titanium alloy.

[0006] This invention is implemented as follows:

[0007] In a first aspect, the present invention provides a method for preparing a copper-chromium-silicon-titanium alloy, comprising the following steps:

[0008] Smelting involves melting raw materials, including copper, chromium, silicon, and titanium, to obtain a melt.

[0009] Continuous casting: Copper-chromium-silicon-titanium alloy rod blanks are formed by continuous casting under an inert gas atmosphere.

[0010] Drawing: The copper-chromium-silicon-titanium alloy rod blank is drawn to form a wire;

[0011] The wire is subjected to aging treatment in an inert gas atmosphere and then cooled in a furnace to obtain the copper-chromium-silicon-titanium alloy wire. The aging treatment temperature is 400℃~500℃ and the time is 1~3h.

[0012] In an optional embodiment, the raw material comprises, by mass fraction, 0.2%-0.5% chromium, 0.02%-0.07% silicon, 0.01%-0.5% titanium, and the balance being copper and unavoidable impurities.

[0013] In an optional embodiment, the raw materials include cathode copper, pure titanium, copper-chromium master alloy, and copper-silicon master alloy.

[0014] In an optional embodiment, the chromium content in the copper-chromium master alloy is 10% to 15%;

[0015] And / or, the silicon content in the copper-silicon master alloy is 20% to 40%.

[0016] In an optional embodiment, the melting temperature in the melting step is 1400℃~1500℃, and the vacuum degree is 0.001Pa~0.1Pa.

[0017] In an optional implementation, the continuous casting speed in the continuous casting step is 1.5 cm / min to 5 cm / min.

[0018] In an optional embodiment, during the continuous casting step, the inlet water temperature is 20℃-30℃ and the water flow rate is 0.5LPM-3LPM.

[0019] In an optional implementation, the drawing step temperature is 12°C-35°C.

[0020] Secondly, the present invention provides a copper-chromium-silicon-titanium alloy wire, which is prepared by the method described in any one of the foregoing embodiments.

[0021] In an optional implementation, the diameter is 3mm-4mm.

[0022] The present invention has the following beneficial effects:

[0023] 1. This invention, through directional solidification continuous casting, essentially eliminates transverse grain boundaries, significantly improving the axial elongation deformation processing capability of copper-chromium-silicon-titanium alloys, which is beneficial for improving production efficiency and reducing production costs.

[0024] 2. The copper-chromium-silicon-titanium alloy prepared by this invention has a fibrous crystalline structure. Due to the low impurity content between the fibrous grain boundaries, the probability of recrystallization nucleation is low. During the aging process, the probability of the grain boundaries acting as nucleation sites is greatly reduced, thereby increasing the recrystallization temperature of the alloy and improving the stress relaxation resistance of the copper-chromium-silicon-titanium alloy. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0026] This invention provides a method for preparing a copper-chromium-silicon-titanium alloy, comprising the following steps:

[0027] Smelting involves melting raw materials, including copper, chromium, silicon, and titanium, to obtain a melt.

[0028] Continuous casting: Copper-chromium-silicon-titanium alloy rod blanks are formed by continuous casting under an inert gas atmosphere.

[0029] Drawing: The copper-chromium-silicon-titanium alloy rod blank is drawn to form a wire;

[0030] The wire is subjected to aging treatment in an inert gas atmosphere and then cooled in a furnace to obtain the copper-chromium-silicon-titanium alloy wire. The aging treatment temperature is 400℃~500℃ and the time is 1~3h.

[0031] This invention, through directional solidification continuous casting, essentially eliminates transverse grain boundaries, significantly improving the axial elongation deformation processing capability of copper-chromium-silicon-titanium alloys, which is beneficial for improving production efficiency and reducing production costs.

[0032] Meanwhile, the copper-chromium-silicon-titanium alloy prepared by this invention has a fibrous crystalline structure. Since the impurity content between the fibrous grain boundaries is low, it is not conducive to recrystallization nucleation. During the aging process, the probability of the grain boundaries acting as nucleation cores is reduced, which increases the recrystallization temperature of the alloy and is beneficial to improving the stress relaxation resistance of the copper-chromium-silicon-titanium alloy.

[0033] In this application, the aging treatment temperature is 400℃~500℃, specifically 400℃, 420℃, 440℃, 460℃, 480℃, 500℃, or any value between 400℃ and 500℃; the time is 1h~3h, specifically 1h, 2h, 3h, or any value between 1h and 3h. If the aging treatment temperature is too high or the time is too long, it will lead to the growth and aggregation of precipitated phases, thereby reducing the stress relaxation resistance.

[0034] In an optional embodiment, the raw material comprises, by mass fraction, 0.2%-0.5% chromium, 0.02%-0.07% silicon, 0.01%-0.5% titanium, and the balance being copper and unavoidable impurities.

[0035] The amount of each component has a significant impact on the properties of copper-chromium-silicon-titanium alloys. In particular, silicon mainly improves the stress relaxation resistance of the alloy through solid solution strengthening, second phase precipitation, and grain boundary purification, while titanium relies more on precipitation strengthening, grain refinement, and grain boundary purification to improve the stress relaxation resistance of the alloy.

[0036] In an optional embodiment, the raw materials include cathode copper, pure titanium, copper-chromium master alloy, and copper-silicon master alloy.

[0037] In an optional embodiment, the chromium content in the copper-chromium master alloy is 10% to 15%;

[0038] And / or, the silicon content in the copper-silicon master alloy is 20% to 40%.

[0039] Using intermediate alloys as raw materials helps to improve the uniformity of the melt, reduce segregation, reduce the introduction of non-metallic inclusions, and facilitate the acquisition of better microstructure and performance consistency.

[0040] In an optional embodiment, the melting temperature in the melting step is 1400℃~1500℃, and the vacuum degree is 0.001Pa~0.1Pa.

[0041] Melting under these conditions ensures that all components are completely dissolved and thoroughly mixed, while also removing some gases and inclusions, which is crucial for improving the alloy's resistance to stress relaxation.

[0042] In an optional implementation, the continuous casting speed in the continuous casting step is 1.5 cm / min to 5 cm / min.

[0043] In the continuous casting process, the casting speed affects the surface quality of the billet. Within the range of 1.5 cm / min to 5 cm / min, specifically any value between 1.5 cm / min, 2 cm / min, 3 cm / min, 4 cm / min, 5 cm / min, or 1.5 cm / min to 5 cm / min, the billet quality and production efficiency can be balanced. If the continuous casting speed is too fast, it will lead to an increase in surface defects of the billet and reduce its resistance to stress relaxation.

[0044] In an optional embodiment, during the continuous casting step, the inlet water temperature is 20℃-30℃ and the water flow rate is 0.5LPM-3LPM.

[0045] The inlet water temperature can be 20℃, 22℃, 24℃, 26℃, 28℃, or 30℃, and the water flow rate can be 1 LPM, 2 LPM, 3 LPM, 4 LPM, or 5 LPM. The inlet water temperature and water flow rate affect the cooling rate, which in turn affects the grain size and the type, quantity, size, and distribution of precipitated phases. In this application, rapid cooling is beneficial for forming a fine and uniform grain structure. This structure can not only improve the hardness of the alloy, but also improve the stress relaxation resistance by reducing grain boundary scattering.

[0046] In an optional implementation, the drawing step temperature is 12°C-35°C.

[0047] The present invention also provides a copper-chromium-silicon-titanium alloy wire, which is prepared by any one of the methods described in the foregoing embodiments.

[0048] In an optional implementation, the diameter is 3mm-4mm.

[0049] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0050] Example 1

[0051] This embodiment provides a method for preparing a copper-chromium-silicon-titanium alloy wire with a diameter of 3mm, specifically including the following steps:

[0052] Using cathode copper, pure titanium, copper-chromium, and copper-silicon master alloys as raw materials, wherein the raw materials contain 0.2% chromium, 0.07% silicon, 0.1% titanium, and the balance copper and unavoidable impurities, the materials are melted at a vacuum of 0.1 Pa and 1500 °C; copper-chromium-silicon-titanium alloy ingots are directionally solidified and continuously cast under an argon atmosphere at a casting speed of 1.5 cm / min, a water inlet temperature of 30 °C, and a water flow rate of 0.5 LPM; the copper-chromium-silicon-titanium alloy ingots are drawn at room temperature to a diameter of 3 mm; the room-temperature drawn copper-chromium-silicon-titanium alloy wires are aged under an argon atmosphere at a temperature of 400 °C for 3 hours, and cooled by furnace cooling.

[0053] Example 2

[0054] This embodiment provides a method for preparing a copper-chromium-silicon-titanium alloy wire with a diameter of 3.6 mm, specifically including the following steps:

[0055] Using cathode copper, pure titanium, copper-chromium, and copper-silicon master alloys as raw materials, wherein the raw materials contain 0.5% chromium, 0.02% silicon, 0.01% titanium, and the balance copper and unavoidable impurities, the materials are melted at a vacuum of 0.001 Pa and 1400 °C; copper-chromium-silicon-titanium alloy ingots are directionally solidified and continuously cast under an argon atmosphere at a casting speed of 1.5 cm / min, a water inlet temperature of 20 °C, and a water flow rate of 3 LPM; the copper-chromium-silicon-titanium alloy ingots are drawn at room temperature to a diameter of 3.6 mm; the room-temperature drawn copper-chromium-silicon-titanium alloy wires are aged under an argon atmosphere at a temperature of 500 °C for 1 hour, and cooled by furnace cooling.

[0056] Example 3

[0057] This embodiment provides a method for preparing a copper-chromium-silicon-titanium alloy wire with a diameter of 4mm, specifically including the following steps:

[0058] Using cathode copper, pure titanium, copper-chromium, and copper-silicon master alloys as raw materials, wherein the raw materials contain 0.3% chromium, 0.03% silicon, 0.5% titanium, and the balance copper and unavoidable impurities, the materials are melted at a vacuum of 0.01 Pa and 1450 °C; copper-chromium-silicon-titanium alloy ingots are directionally solidified and continuously cast under an argon atmosphere at a casting speed of 2 cm / min, a water inlet temperature of 25 °C, and a water flow rate of 1 LPM; the copper-chromium-silicon-titanium alloy ingots are drawn at room temperature to a diameter of 4 mm; the room-temperature drawn copper-chromium-silicon-titanium alloy wires are aged under an argon atmosphere at a temperature of 450 °C for 2 hours, and cooled by furnace cooling.

[0059] Comparative Example 1

[0060] The only difference between this comparative example and Example 1 is that non-vacuum casting is used instead of continuous casting. The specific steps of this process are as follows: first, the ingot is melted at 1500°C in an atmospheric environment and then cast into a billet; then, it is hot-forged into a bar at 930°C; next, it is quenched at 950°C and then drawn to an outer diameter of 3mm; finally, the aging treatment temperature is 400°C for 3 hours, and the cooling method is furnace cooling.

[0061] Comparative Example 2

[0062] The only difference between this comparative example and Example 1 is that the aging process step is omitted.

[0063] Comparative Example 3

[0064] The only difference between this comparative example and Comparative Example 1 is that the time-sensitive processing step is omitted.

[0065] Comparative Example 4

[0066] The only difference between this comparative example and Example 1 is that the continuous casting speed is 8 cm / min, the inlet water temperature is 15°C, and the water flow rate is 4 LPM.

[0067] Comparative Example 5

[0068] The only difference between this comparative example and Example 1 is that the continuous casting speed is 0.5 cm / min, the inlet water temperature is 18°C, and the water flow rate is 5 LPM.

[0069] Comparative Example 6

[0070] The only difference between this comparative example and Example 1 is that the aging treatment temperature is 350°C and the time is 6 hours.

[0071] Comparative Example 7

[0072] The only difference between this comparative example and Example 1 is that the aging treatment temperature is 550°C and the time is 0.5h.

[0073] The stress relaxation resistance of the copper-chromium-silicon-titanium alloy wires prepared in the above embodiments and comparative examples was tested. The test results are shown in Table 1. The test method refers to GB / T 10120-2013 standard.

[0074] Table 1 Stress relaxation resistance of copper-chromium-silicon-titanium alloy wires

[0075] Stress relaxation rate at room temperature Stress relaxation rate at 100℃ Stress relaxation rate at 200℃ Example 1 6.3 8.7 9.7 Example 2 7.5 9.7 10.8 Example 3 7.1 8.9 9.8 Comparative Example 1 9.5 11.8 14.2 Comparative Example 2 10.2 13.6 15.7 Comparative Example 3 11.3 14.5 16.2 Comparative Example 4 8.3 11.6 14.5 Comparative Example 5 9.1 12.3 14.4 Comparative Example 6 8.5 10.2 12.1 Comparative Example 7 8.8 10.9 12.8

[0076] As can be seen from Table 1, the copper-chromium-silicon-titanium alloy wire prepared within the parameter range of the present invention has a lower stress relaxation rate at different temperatures compared with the wire prepared under other parameters, indicating that the copper-chromium-silicon-titanium alloy wire prepared by the method of the present invention has better stress relaxation resistance.

[0077] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing a copper-chromium-silicon-titanium alloy, characterized in that, Includes the following steps: Smelting involves melting raw materials including copper, chromium, silicon, and titanium to obtain a melt; the raw materials, by mass fraction, include 0.2%-0.5% chromium, 0.02%-0.07% silicon, 0.01%-0.5% titanium, and the balance being copper and unavoidable impurities; Continuous casting: Copper-chromium-silicon-titanium alloy rods are formed by directional solidification and continuous casting under an inert gas atmosphere. The continuous casting speed is 1.5cm / min-5cm / min, the inlet water temperature is 20℃-30℃, and the water flow rate is 0.5LPM-3LPM. Drawing: The copper-chromium-silicon-titanium alloy rod blank is drawn to form a wire; The wire is subjected to aging treatment in an inert gas atmosphere and then cooled in a furnace to obtain copper-chromium-silicon-titanium alloy wire. The aging treatment temperature is 400℃~500℃ and the time is 1~3h.

2. The method for preparing copper-chromium-silicon-titanium alloy according to claim 1, characterized in that, The raw materials include cathode copper, pure titanium, copper-chromium master alloy, and copper-silicon master alloy.

3. The method for preparing copper-chromium-silicon-titanium alloy according to claim 2, characterized in that, The chromium content in the copper-chromium master alloy is 10%~15%; And / or, the silicon content in the copper-silicon master alloy is 20% to 40%.

4. The method for preparing the copper-chromium-silicon-titanium alloy according to claim 1, characterized in that, During the smelting process, the smelting temperature is 1400℃~1500℃ and the vacuum degree is 0.001Pa~0.1Pa.

5. The method for preparing the copper-chromium-silicon-titanium alloy according to claim 1, characterized in that, The temperature for the drawing process is 12℃-35℃.

6. A copper-chromium-silicon-titanium alloy wire, characterized in that, It is prepared by the method described in any one of claims 1-5.

7. The copper-chromium-silicon-titanium alloy wire according to claim 6, characterized in that, The diameter is 3mm-4mm.