阅读说明：本技术 一种含有Cr2Nb相的高强高导耐高温铜合金的制备方法 (Cr-containing alloy2Preparation method of Nb-phase high-strength high-conductivity high-temperature-resistant copper alloy ) 是由 张石松 王小军 刘凯 李鹏 姚培建 马明月 师晓云 赵俊 王文斌 李刚 于 2020-04-21 设计创作，主要内容包括：本发明公开了一种含有Cr<Sub>2</Sub>Nb相的高强高导耐高温铜合金的制备方法,属于铜合金制备技术领域,在传统铬锆铜材料的基础上引入了Nb元素,并且在进行铸锭前对Nb粉、Cr粉进行充分活化,得到非平衡的过饱和固溶体,使得铜合金铸锭中更易形成Cr<Sub>2</Sub>Nb相。并且采用雾化制粉和3D打印两联结合的工艺,在雾化制粉过程中采用低温氩气高压冷风气流对金属液滴进行铸冷处理,保证了Cr<Sub>2</Sub>Nb相的细小和处于充分的过饱和态,提高了析出相的弥散强化效果。本发明还充分利用了3D打印优势,不仅能够制备复杂形状的零件,且制得的零件均具有得强度高且耐高温性能优良的优点。(The invention discloses a Cr-containing alloy 2 A preparation method of Nb-phase high-strength high-conductivity high-temperature-resistant copper alloy belongs to the technical field of copper alloy preparation, and introduces Nb element on the basis of the traditional chromium-zirconium-copper material, and fully activates Nb powder and Cr powder before ingot casting to obtain unbalanced supersaturated solid solution, so that copper alloy ingot casting is carried outMedium to easy form Cr 2 And (4) a Nb phase. And the atomization powder making and 3D printing combined process is adopted, and the low-temperature argon high-pressure cold air flow is adopted to carry out cast cooling treatment on the metal liquid drops in the atomization powder making process, so that Cr is ensured 2 The Nb phase is fine and in a sufficient supersaturated state, and the dispersion strengthening effect of the precipitated phase is improved. The invention also makes full use of the 3D printing advantages, not only can prepare parts with complex shapes, but also the prepared parts have the advantages of high strength and excellent high temperature resistance.)

1. Cr-containing alloy₂The preparation method of the Nb-phase high-strength high-conductivity high-temperature-resistant copper alloy is characterized by comprising the following steps of:

(1) preparing materials: proportioning copper alloy elements according to the weight percentage of 0.3-4% of Cr, 0.1-1% of Zr, 0.3-4% of Nb and the balance of Cu, and selecting and weighing corresponding raw materials;

(2) atomizing to prepare powder: refining the raw materials, and then preparing the raw materials into the Cr-containing alloy by adopting a vacuum induction gas atomization method or cooling the raw materials into ingots by adopting an electrode induction gas atomization method₂Spherical powder of Nb phase;

(3)3D printing the section bar: selecting spherical powder with the granularity interval of 20-100 mu m as a 3D printing raw material, and performing 3D printing on the raw material through an energy beam to obtain a saturated copper alloy section;

(4) aging treatment: carrying out aging treatment on the 3D printed copper alloy section, controlling the temperature at 300-500 ℃ and the aging time at 2-5h to obtain a 3D printed sample piece;

(5) and (3) machining: and machining equipment is adopted to perform finished product processing on the 3D printing sample piece according to the drawing requirements.

2. The method of claim 1, further comprising Cr₂The preparation method of the Nb-phase high-strength high-conductivity high-temperature-resistant copper alloy is characterized in that the raw material refining method in the step (2) comprises the following steps:

s1: spreading Cr at the bottom of a ceramic box in a Cr powder form, paving the ceramic box with the thickness of 1-2mm, introducing argon to remove air in a sealed box, keeping the air pressure in the sealed box at 0.5-0.7MPa, filling Nb in a Nb powder form into a supersonic particle bombardment spray gun, uniformly spraying the Nb powder at a speed of 250 plus materials and 300m/s at a distance of 50mm from the Cr powder, so that the Nb powder and the Cr powder are quickly combined, and then fully activating by adopting mechanical ball milling for 2h to obtain a non-balanced supersaturated solid solution;

s2: putting a copper raw material into a ceramic crucible, heating to 1300 ℃ until the copper raw material is completely melted, then adding the supersaturated solid solution, heating to 1700 ℃ until the copper raw material is completely melted, finally adding a Zr raw material, heating to 1900 ℃ until the copper raw material is completely melted, pouring the molten liquid in the ceramic crucible into a water-cooled mold, cooling for 1h to obtain a primary alloy ingot, and directly preparing the primary alloy ingot into powder by adopting an electrode induction gas atomization method, or smelting the primary alloy ingot into liquid and then preparing the powder by adopting a vacuum induction gas atomization method.

3. The method of claim 2, wherein the Cr is contained₂The preparation method of the Nb-phase high-strength high-conductivity high-temperature-resistant copper alloy is characterized in that the raw material refining method further comprises the following steps:

s3: placing the copper alloy cast ingot into a die, and forging and pressing the copper alloy cast ingot in sequence along the X-axis direction, the Y-axis direction and the Z-axis direction respectively, wherein the deformation of the copper alloy cast ingot in the X-axis direction and the Y-axis direction is not less than 40% and the deformation of the copper alloy cast ingot in the Z-axis direction is not less than 70%, and forging and pressing the copper alloy cast ingot into a plate;

s4: rolling the plate for 10-20 times at room temperature, wherein the deformation amount of each time is not less than 15%;

s5: cutting the rolled plate into strips, loading the strips into a feeding mechanism of an electron beam melting device, carrying out secondary remelting on the rolled plate by adopting an electron beam remelting technology, cooling and crystallizing to obtain a secondary alloy ingot, and preparing the secondary alloy ingot into powder by directly adopting an electrode induction gas atomization method, or preparing the powder by adopting a vacuum induction gas atomization method after smelting into liquid.

4. A composition comprising Cr as claimed in claim 1 or 2₂The preparation method of the Nb-phase high-strength high-conductivity high-temperature-resistant copper alloy is characterized in that in the step (1), Cu is an electrolytic copper plate with the purity of more than or equal to 99.990%, crystalline Zr with the purity of more than or equal to 99.9% is adopted as Zr, Cr powder with the purity of more than or equal to 99.9% and the grain size of 50-90 mu m is adopted as Cr, and Nb powder with the purity of more than or equal to 99.5% and the grain size of 10-20 mu m is adopted as Nb.

5. The method of claim 1, further comprising Cr₂The preparation method of the Nb-phase high-strength high-conductivity high-temperature-resistant copper alloy is characterized in that the vacuum induction gas atomization method and the electrode induction gas atomization method in the step (2) both adopt supersonic closely-coupled atomizing nozzles to spray high-pressure airflow to atomize and crush the metal liquid of the copper alloy ingot into fine liquid drops, and the fine liquid drops are solidified into particles in low-temperature argon high-pressure cold airflow.

6. The method of claim 4, wherein the Cr is contained₂The preparation method of the Nb-phase high-strength high-conductivity high-temperature-resistant copper alloy is characterized in that the temperature of the low-temperature argon high-pressure cold air flow is-20 to-10 ℃, and the pressure is 80 to 100 atm.

7. The method of claim 1, further comprising Cr₂The preparation method of the Nb-phase high-strength high-conductivity high-temperature-resistant copper alloy is characterized in that the energy beam in the step (3) is any one of a laser beam, an electron beam or a plasma beam.

Technical Field

The invention belongs to the technical field of copper alloy preparation, and particularly relates to a Cr-containing alloy₂A preparation method of Nb phase high-strength high-conductivity high-temperature-resistant copper alloy.

Background

The copper-chromium-zirconium material is mainly applied to industries such as high-speed rail transit, welding engineering, metallurgy, electric power, lead frame materials and the like due to the characteristics of high strength and high conductivity. At present, the conventional production process is to improve the mechanical property of the material by utilizing precipitation strengthening of two elements of Cr and Zr through a heat treatment mode of solid solution aging, so that the high strength and the high conductivity of the material are limited by temperature, the softening temperature of the material is about 550 ℃, the application field of the material is limited, and the conventional copper, chromium and zirconium is prepared by adopting the processes of smelting and casting, the phase structures of Cr and Zr are thick, so that the characteristics of high strength and high conductivity of the material are difficult to fully exert through the solid solution aging.

Disclosure of Invention

In view of the above problems, the present invention provides a Cr-containing alloy₂A preparation method of Nb phase high-strength high-conductivity high-temperature-resistant copper alloy.

The preparation method comprises the following steps: cr-containing alloy₂The preparation method of the Nb-phase high-strength high-conductivity high-temperature-resistant copper alloy comprises the following steps of:

(1) preparing materials: proportioning copper alloy elements according to the weight percentage of 0.3-4% of Cr, 0.1-1% of Zr, 0.3-4% of Nb and the balance of Cu, and selecting and weighing corresponding raw materials;

(2) atomizing to prepare powder: refining the raw materials, and then preparing the raw materials into the Cr-containing alloy by adopting a vacuum induction gas atomization method or cooling the raw materials into ingots by adopting an electrode induction gas atomization method₂Spherical powder of Nb phase;

(3)3D printing the section bar: selecting spherical powder with the granularity interval of 20-100 mu m as a 3D printing raw material, and performing 3D printing on the raw material through an energy beam to obtain a saturated copper alloy section;

(4) aging treatment: carrying out aging treatment on the 3D printed copper alloy section, controlling the temperature at 300-500 ℃ and the aging time at 2-5h to obtain a 3D printed sample piece;

(5) and (3) machining: and machining equipment is adopted to perform finished product processing on the 3D printing sample piece according to the drawing requirements.

Further, the method for refining the raw material in the step (2) comprises the following steps:

s1: spreading Cr at the bottom of a ceramic box in a Cr powder form, paving the ceramic box with the thickness of 1-2mm, introducing argon to remove air in a sealed box, keeping the air pressure in the sealed box at 0.5-0.7MPa, filling Nb in a Nb powder form into a supersonic particle bombardment spray gun, uniformly spraying the Nb powder at a speed of 250 plus materials and 300m/s at a distance of 50mm from the Cr powder, so that the Nb powder and the Cr powder are quickly combined, and then fully activating by adopting mechanical ball milling for 2h to obtain a non-balanced supersaturated solid solution; is beneficial to shortening the diffusion distance of atoms and improving the diffusion speed of the atoms in the subsequent smelting process, so that Cr₂The Nb phase is easier to generate, and simultaneously, the reduction of the product density caused by poor diffusion capability of Cr and Nb atoms when directly mixing Cr powder and Nb powder for smelting is avoided.

S2: putting a copper raw material into a ceramic crucible, heating to 1300 ℃ until the copper raw material is completely melted, then adding the supersaturated solid solution, heating to 1700 ℃ until the copper raw material is completely melted, finally adding a Zr raw material, heating to 1900 ℃ until the copper raw material is completely melted, pouring the molten liquid in the ceramic crucible into a water-cooled mold, cooling for 1h to obtain a primary alloy ingot, and directly adopting an electrode induction gas atomization method to prepare powder or adopting a vacuum induction gas atomization method to prepare powder after smelting into liquid.

Further, the preparation method of the non-equilibrium supersaturated solid solution can be replaced by: cr and Nb are respectively loaded into a first supersonic particle bombardment spray gun and a second supersonic particle bombardment spray gun in a Cr powder form and a Nb powder form, wherein the first supersonic particle bombardment spray gun and the second supersonic particle bombardment spray gun are oppositely sprayed in a ceramic seal box filled with argon protection along the X axis in the same direction, the spraying speeds of the Cr powder and the Nb powder are both 250-plus-300 m/s, and the powder feeding amount of the Cr powder is 2 times of the atomic ratio of the Nb powder, so that the Cr powder and the Nb powder are oppositely sprayed in the air and rapidly combined, compared with the method of dynamically spraying the Nb powder after flatly spreading the Cr powder, the contact rate of the Cr powder and the Nb powder can be greatly improved, and then mechanical ball milling is adopted for 2 hours for full activation, so that a non-balanced supersaturated solid solution is obtained.

Still further, the method of refining a feedstock further comprises:

s3: placing the copper alloy cast ingot into a die, and forging and pressing the copper alloy cast ingot in sequence along the X-axis direction, the Y-axis direction and the Z-axis direction respectively, wherein the deformation of the copper alloy cast ingot in the X-axis direction and the Y-axis direction is not less than 40% and the deformation of the copper alloy cast ingot in the Z-axis direction is not less than 70%, and forging and pressing the copper alloy cast ingot into a plate;

s4: rolling the plate for 10-20 times at room temperature, wherein the deformation amount of each time is not less than 15%;

s5: cutting the rolled plate into strips, loading the strips into a feeding mechanism of an electron beam melting device, carrying out secondary remelting on the rolled plate by adopting an electron beam remelting technology, cooling and crystallizing to obtain a secondary alloy ingot, and preparing the secondary alloy ingot into powder by directly adopting an electrode induction gas atomization method or preparing the powder by adopting a vacuum induction gas atomization method after smelting into liquid. After the primary alloy ingot is subjected to forging and rolling for multiple times, and electron beam remelting is carried out, Cr in the secondary alloy ingot can be obtained₂The Nb crystal grains are refined again to the nanometer level, and then the secondary alloy ingot is atomized to prepare Cr in the metal powder₂Nb grains are more dense and uniform.

Further, in the step (1), the Cu is an electrolytic copper plate with the purity of more than or equal to 99.990%, the Zr is crystallized Zr with the purity of more than or equal to 99.9%, the Cr is Cr powder with the purity of more than or equal to 99.9% and the grain size of 50-90 microns, and the Nb is Nb powder with the purity of more than or equal to 99.5% and the grain size of 10-20 microns.

Further, in the vacuum induction gas atomization method and the electrode induction gas atomization method in the step (2), supersonic closely coupled atomizing nozzles are adopted to spray high-pressure airflow to atomize and break the metal liquid of the copper alloy ingot into fine liquid drops, and the fine liquid drops are solidified into particles in low-temperature argon high-pressure cold airflow. The metal liquid drops processed by the supersonic tightly-coupled atomizing nozzle are regular in shape, uniform in size and small in particle size.

Furthermore, the temperature of the low-temperature argon high-pressure cold air flow is-20 to-10 ℃, and the pressure is 80 to 100 atm. Compared with the conventional natural cooling, the method adopts low-temperature argon high-pressure cold air flow to carry out casting cooling treatment, thereby ensuring that Cr is contained₂The fine dispersion of Nb phase improves the strength and high temperature resistance of the material.

Further, the energy beam in the step (3) is any one of a laser beam, an electron beam, or a plasma beam.

The invention has the beneficial effects that:

(1) according to the invention, Nb element is introduced on the basis of the traditional chromium-zirconium-copper material, and Nb powder and Cr powder are fully activated before ingot casting to obtain a non-equilibrium supersaturated solid solution, so that Cr is more easily formed in a copper alloy ingot casting₂And (4) a Nb phase.

(2) The invention adopts the process of combining atomization powder preparation and 3D printing, and adopts low-temperature argon high-pressure cold air flow to carry out cast cooling treatment on the metal liquid drops in the atomization powder preparation process, thereby ensuring that Cr is contained₂The Nb phase is fine and in a sufficient supersaturated state, and the dispersion strengthening effect of the precipitated phase is improved.

(3) The invention fully utilizes the 3D printing advantages, not only can prepare parts with complex shapes, but also the prepared parts have the advantages of high strength and excellent high temperature resistance.

Drawings

FIG. 1 is a graphical representation of the morphology of CuCrNb powder prepared in example 7 of the invention;

FIG. 2 is a phase diagram of CuCrNb prepared in example 7 of the present invention.

Detailed Description