Method for preparing copper-chromium-niobium alloy through mechanical alloying

Abstract

The invention provides a method for preparing a copper-chromium-niobium alloy through mechanical alloying. Comprising the steps that metal powder of copper, chromium and niobium is weighed according to the alloy component proportion, mechanical alloying and screening are conducted, the evenly-mixed alloy powder is loaded into a rubber sheath, the rubber sheath is put into an isostatic press to be pressed, an alloy block obtained after isostatic pressing is taken out and put into a degassing furnace to be subjected to degassing treatment, and it is guaranteed that oxygen, nitrogen and other gas impurities in an alloy sample are low; the alloy block obtained after degassing treatment is put into a vacuum suspension smelting furnace to be smelted, and a copper-chromium-niobium alloy cast ingot is obtained under argon shielding, in the alloy prepared through the method, the niobium content ranges from 6% to 6.5%, the chromium content ranges from 7% to 7.5%, the content of gas impurities such as oxygen and nitrogen is low, alloying of metal is achieved through machinery, and the technology is simple and convenient to operate.

Description

Technical Field

[0001] This invention relates to the field of alloy preparation technology, and in particular to a method for preparing copper-chromium-niobium alloys by mechanical alloying. Background Technology

[0002] Copper-chromium-niobium alloys are high-performance copper alloys that achieve precipitation and dispersion strengthening through the addition of chromium and niobium. Their core value lies in their excellent comprehensive properties: while maintaining good electrical and thermal conductivity, they achieve high strength, high hardness, and especially outstanding high-temperature stability and resistance to softening, along with good wear resistance and machinability. This makes them irreplaceable in harsh environments requiring simultaneous high temperature, high stress, and high current / heat flux (such as high-end welding electrodes, lead frames, and high-power heat dissipation components), and a crucial alternative to toxic or expensive alloys like copper-beryllium alloys.

[0003] In existing technologies, such as CN202411784740.9, the preparation method for this alloy is mostly as follows: first, metallic niobium and metallic chromium are pre-melted to obtain a niobium-chromium master alloy; then, the niobium-chromium alloy is mixed and smelted with metallic copper to obtain a Cu4Cr2Nb alloy. Next, the Cu4Cr2Nb alloy is atomized to obtain the alloy powder, which is then subjected to cold isostatic pressing, hot isostatic pressing, and hot extrusion to obtain a Cu4Cr2Nb alloy ingot. Finally, after machining, a copper-chromium-niobium alloy is obtained. This technology first melts niobium and chromium into a binary alloy, then melts this binary alloy with a copper rod to form an alloy liquid, and then forms an alloy ingot through isostatic pressing. The process is complex, and because it involves two high-temperature melting processes, the material is severely burned, meaning that many other impurities are introduced, and the quality of the prepared product cannot meet the requirements of high-end applications. Furthermore, the copper-chromium-niobium alloy prepared by this technology has low niobium and chromium content, and the niobium and chromium are not effectively dissolved in the copper matrix. Summary of the Invention

[0004] In view of the above-mentioned shortcomings, the present invention proposes a method for preparing copper-chromium-niobium alloy by mechanical alloying, comprising the following steps: Powder preparation: Weigh out the metal powders of copper, chromium, and niobium according to the alloy composition ratio; Mechanical alloying: The above metal powder is added to a ball mill jar and then mixed in a mixer; Screening: The mixed powder is vibrated and screened to remove powder particles that are too large during the mixing process; Pressing: The uniformly mixed alloy powder is loaded into a rubber sleeve and placed into an isostatic press for pressing; Degassing: After the isostatically pressed alloy block is taken out, it is placed in a degassing furnace for degassing treatment to ensure that the oxygen, nitrogen and other gaseous impurities in the alloy sample are low. Melting into ingots: The degassed alloy blocks are placed in a vacuum suspension melting furnace for melting, and copper-chromium-niobium alloy ingots are obtained under argon protection.

[0005] Preferably, in the mechanical alloying step, the ball-to-material ratio in the ball mill is 10:1 to 20:1, and the mixing time is 6 to 8 hours.

[0006] Preferably, in the pressing step, the holding time is 5 to 8 hours.

[0007] Preferably, in the degassing step, the degassing time is 6-8 hours and the furnace temperature is maintained at 400°C.

[0008] Preferably, the copper-chromium-niobium alloy contains 6-6.5% niobium and 7-7.5% chromium, with the balance being copper and unavoidable impurities.

[0009] Preferably, in the copper-chromium-niobium alloy, the oxygen content of gaseous impurities does not exceed 0.005%, and the nitrogen content of gaseous impurities does not exceed 0.002%.

[0010] The alloy prepared by the method of this invention has a niobium content of 6-6.5%, a chromium content of 7-7.5%, and low content of gaseous impurities such as oxygen and nitrogen. The alloying of the metal is achieved mechanically, and the process is simple and convenient to operate. Attached Figure Description

[0011] Figure 1 This is the XRD pattern of the copper-chromium-niobium alloy from Embodiment 1 of the present invention. The pattern shows that, through the method of the present invention, the alloy contains no elemental chromium or niobium other than the base material copper; both chromium and niobium exist in a binary alloying form. The degree of mechanical alloying is high. Detailed Implementation

[0012] Example 1 872g of copper powder, 68g of chromium powder, and 60g of niobium powder were weighed and placed in a ball mill jar. A small amount of alcohol and zirconium oxide grinding balls were added to the jar, and the mixture was mechanically alloyed in a ball mill for 8 hours. The alloyed powder was then sieved in a vibrating sieve to remove agglomerated and excessively large particles from the alloying process. Subsequently, the sieved powder was placed in a rubber sheath and cold-pressed in a cold isostatic press. The press pressure was increased to the limit pressure and held for 6 hours. After cold pressing, the alloy block was removed from the rubber sheath and placed in a degassing furnace. The furnace was then evacuated until the vacuum level inside the furnace was below 1.0 × 10⁻⁶. -2After Pa, the heating program is started, heating is performed at a rate of 5℃ / min while continuously evacuating the vacuum. Once the temperature reaches 400℃, it is held for 6 hours while continuing to evacuate the vacuum. After the holding period, the degassed alloy briquettes are placed in the vacuum levitation furnace crucible for melting. In the early stages of melting, the vacuum inside the furnace is evacuated to 5.0 × 10⁻⁶. -3 During melting, the power was increased at a rate of 30 kW / min. After the material was completely melted, the power was maintained for 10 minutes before melting was completed. After the alloy was allowed to cool naturally in the crucible for 40 minutes, the crucible was broken open, and the copper-chromium-niobium alloy was removed from the crucible.

[0013] Sampling and testing of copper-chromium-niobium alloys were conducted, and the niobium content was 6.3%, the chromium content was 7.5%, the oxygen content was 0.0048%, the nitrogen content was no more than 0.002%, and the balance was copper and unavoidable impurities.

[0014] Example 2 Weigh out 910g of copper powder, 50g of chromium powder, and 44g of niobium powder. Place the powders into a ball mill jar, add a small amount of alcohol and zirconium oxide grinding balls, and perform mechanical alloying treatment on a ball mill for 6 hours. After alloying, sieve the powder using a vibrating sieve to remove agglomerated and excessively large particles from the alloying process. Then, place the sieved powder into a rubber sheath and cold-press it in a cold isostatic press, increasing the press pressure to the limit and holding it for 5 hours. After cold pressing, remove the alloy block from the rubber sheath and place it in a degassing furnace. Vacuum the furnace interior until the vacuum level is below 1.0 × 10⁻⁶. -2 After Pa, the heating program is started, heating is carried out at a rate of 5℃ / min while continuously evacuating the vacuum. Once the temperature reaches 400℃, it is held for 6.5 hours while continuing to evacuate the vacuum. After the holding period, the degassed alloy briquettes are placed in the vacuum levitation furnace crucible for melting. In the early stages of melting, the vacuum inside the furnace is evacuated to 4.0 × 10⁻⁶. -3 During melting, the power was increased at a rate of 50 kW / min. After the material was completely melted, the power was maintained for 13 minutes to end the melting process. After the alloy was allowed to cool naturally in the crucible for 50 minutes, the crucible was broken open, and the copper-chromium-niobium alloy was removed from the crucible.

[0015] Sampling and testing of copper-chromium-niobium alloys were conducted, with niobium content of 6.5%, chromium content of 7.4%, oxygen content of 0.0044%, nitrogen content not exceeding 0.002%, and the balance being copper and unavoidable impurities.

[0016] Example 3 Weigh out 900g of copper powder, 60g of chromium powder, and 50g of niobium powder. Place the powders into a ball mill jar, add a small amount of alcohol and zirconium oxide grinding balls, and perform mechanical alloying treatment on a ball mill for 6 hours. After alloying, sieve the powder using a vibrating sieve to remove agglomerated and excessively large particles from the alloying process. Then, place the sieved powder into a rubber sheath and cold-press it in a cold isostatic press, increasing the press pressure to the limit and holding it for 5 hours. After cold pressing, remove the alloy block from the rubber sheath and place it in a degassing furnace. Vacuum the furnace interior until the vacuum level is below 1.0 × 10⁻⁶. -2 After Pa, the heating program is started, heating at a rate of 5℃ / min while continuously evacuating the vacuum. Once the temperature reaches 400℃, it is held for 6 hours while continuing to evacuate the vacuum. After holding, the degassed alloy briquettes are placed in the crucible of a vacuum levitation furnace for rotary cup melting. During the initial melting stage, the vacuum inside the furnace is evacuated to 8.7 × 10⁻⁶. -3 During melting, the power was increased at a rate of 60 kW / min. After the material was completely melted, the power was maintained for 18 minutes to end the melting process. After the alloy was allowed to cool naturally in the crucible for 50 minutes, the crucible was broken open, and the copper-chromium-niobium alloy was removed from the crucible.

[0017] Sampling and testing of copper-chromium-niobium alloys were conducted, with niobium content of 6.2%, chromium content of 7.2%, oxygen content of 0.0045%, nitrogen content not exceeding 0.002%, and the balance being copper and unavoidable impurities.

[0018] The embodiments of this solution have been described in detail above. However, this solution is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of this patent.

Claims

1. A method for preparing copper-chromium-niobium alloys by mechanical alloying, characterized in that... Includes the following steps: Powder preparation: Weigh out the metal powders of copper, chromium, and niobium according to the alloy composition ratio; Mechanical alloying: The above metal powder is added to a ball mill jar and then mixed in a mixer; Screening: The mixed powder is vibrated and screened to remove powder particles that are too large during the mixing process; Pressing: The uniformly mixed alloy powder is loaded into a rubber sleeve and placed into an isostatic press for pressing; Degassing: After the isostatically pressed alloy block is taken out, it is placed in a degassing furnace for degassing treatment to ensure that the oxygen, nitrogen and other gaseous impurities in the alloy sample are low. Melting into ingots: The degassed alloy blocks are placed in a vacuum suspension melting furnace for melting, and copper-chromium-niobium alloy ingots are obtained under argon protection.

2. The method for preparing copper-chromium-niobium alloy by mechanical alloying as described in claim 1, characterized in that: In the mechanical alloying step, the ball-to-material ratio in the ball mill is 10:1 to 20:1, and the mixing time is 6 to 8 hours.

3. The method for preparing copper-chromium-niobium alloy by mechanical alloying as described in claim 1, characterized in that: In the pressing step, the holding time is 5 to 8 hours.

4. The method for preparing copper-chromium-niobium alloy by mechanical alloying as described in claim 1, characterized in that: In the degassing step, the degassing time is 6-8 hours, and the furnace temperature is maintained at 400℃.

5. The method for preparing copper-chromium-niobium alloy by mechanical alloying as described in claim 1, characterized in that: The copper-chromium-niobium alloy contains 6-6.5% niobium and 7-7.5% chromium, with the balance being copper and unavoidable impurities.

6. The method for preparing copper-chromium-niobium alloy by mechanical alloying as described in claim 1, characterized in that: In the copper-chromium-niobium alloy, the oxygen content of gaseous impurities does not exceed 0.005%, and the nitrogen content of gaseous impurities does not exceed 0.002%.

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