Spray forming method for preparing copper alloy

Abstract

The invention discloses a spray forming method for preparing copper alloy. According to the spray forming method, liquid metal atomization and the deposition phase of atomized molten drops are uniformly combined, so that flowing of segregation liquid phases among dendrites is reduced, formation of macrosegregation is avoided, and the compact metal blank with the rapid solidification structure characteristic can be directly prepared. According to the spray forming method, a high-pressure nitrogen atomization process is adopted, so that alloy melt is atomized into small alloy particles, the surface area of the melt is increased, and therefore the cooling speed is increased, rapid solidification is promoted, grain refinement is facilitated, and the mechanical performance of the material is improved; by controlling the deposition rate and the spraying distance, the size and the shape of the alloy ingot blank can be accurately controlled, the consistency and repeatability of products are ensured, and meanwhile material waste is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of metal material processing and particularly relates to a spray forming method for preparing a copper alloy. Background Art

[0002] The existing methods for preparing copper alloys are mainly smelting casting and forging. Smelting casting is a method of melting the copper alloy raw material, pouring it into a mold, cooling and solidifying it into a shape. This method can produce copper alloy parts with complex shapes, but the material is prone to coarse grains and segregation problems. Forging is a method of heating the copper alloy raw material to a certain temperature and then forging or compressing it. This method can improve the mechanical properties of the material, but because it requires multiple heating and cooling, it is easy to cause defects such as thermal stress and cold stress inside the material.

[0003] At the same time, the existing copper alloy preparation method cannot solve the problem of segregation of low-melting-point elements during the preparation process, which can easily lead to serious impact on the mechanical properties and service life of the material. In addition, the existing copper alloy preparation method requires multiple heating and cooling, and has problems such as low production efficiency, high energy consumption, and high cost. Therefore, how to prepare copper alloy parts without macroscopic segregation and solve the problem of segregation of low-melting-point elements is one of the main problems facing the current copper alloy preparation field. Summary of the invention

[0004] The purpose of the present disclosure is to provide a spray forming method for preparing a copper alloy, which can solve at least part of the above technical problems.

[0005] A first aspect of an embodiment of the present disclosure provides a spray forming method for preparing a copper alloy, the spray forming method comprising:

[0006] After the copper alloy material raw material is heated and melted into alloy melt, it is transferred to the funnel of the spray forming equipment so that the alloy melt flows into the atomizer;

[0007] The high-pressure nitrogen atomization process atomizes the alloy melt into gaseous alloy small particles and sprays them out from the nozzle of the atomizer;

[0008] Before the alloy particles are completely solidified, they are deposited on a collector and form an alloy ingot.

[0009] The main technical effects achieved by the disclosed embodiments are: using high-pressure inert gas to atomize the metal liquid flow into fine droplets, controlling the gas pressure and flow rate, and the diameter of the nozzle. The diameter of the fine droplets is generally at the micron level, which can increase the surface area of ​​the droplets and improve their cooling rate; the atomized metal droplets will fly along the axis of the nozzle at a very high speed, controlling the structure of the nozzle and the initial velocity of the droplets. The droplets flying at high speed will experience strong cooling and solidification during the flight, thereby forming rapid solidification organizational characteristics; before the droplets are completely solidified, they are deposited on the collector; the structure and position of the collector are controlled so that the droplets can be uniformly deposited on the collector. In the preparation process, by controlling the cooling rate and the temperature gradient during the deposition process, and optimizing the nozzle structure, gas pressure and flow rate and other parameters to suppress the segregation problem, a blank with uniform composition is prepared; due to the rapid solidification characteristics of the injection molding technology, the segregation problem in the preparation process of copper alloys can be significantly improved and energy consumption and costs can be reduced. Through the above technical means, copper alloy billets with refined grain structure and uniform composition can be produced, and verified through performance testing and quality inspection of the final product.

[0010] Optionally, the copper alloy material raw materials include copper Cu, nickel Ni and tin Sn, and are mixed in a weight ratio of 73-81 parts of copper Cu, 13-17 parts of nickel Ni and 6-10 parts of tin Sn.

[0011] The main technical effect achieved by the embodiment of the present disclosure is: copper Cu73-81, nickel Ni13-17 and tin Sn6-10 are mixed in a specific weight ratio. The addition of nickel improves the strength and corrosion resistance of the alloy, while the addition of tin improves the casting performance and cutting performance of the alloy; precise control of the alloy component ratio helps to form a uniform microstructure, reduce segregation, and improve the overall performance of the material.

[0012] Optionally, before being transferred to the funnel of the injection molding equipment, the alloy melt is heated and melted in a medium frequency furnace protected by inert gas, wherein the power of the medium frequency furnace is 200-300 kW and the heating rate is controlled at 10-20°C / min.

[0013] The main technical effects achieved by the embodiments of the present disclosure are: heating and melting in a medium-frequency furnace protected by inert gas reduces oxidation of the alloy during the melting process, maintains the purity of the alloy, and improves the corrosion resistance and electrical conductivity of the material; controlling the heating rate helps to uniformly heat the molten alloy and reduce material defects caused by local overheating or uneven heating.

[0014] Optionally, the inner wall of the funnel of the injection molding equipment is coated with an anti-adhesion coating, and the thickness of the anti-adhesion coating is 0.1 to 0.3 mm.

[0015] The main technical effects achieved by the embodiments of the present disclosure are: the anti-sticking coating reduces the adhesion of the alloy melt to the inner wall of the funnel, reduces the need for cleaning, and improves production efficiency; the wear resistance and heat resistance of the Teflon coating help to extend the service life of the injection molding equipment.

[0016] Optionally, during the deposition process of the small alloy particles, the deposition rate is 5 to 8 kg / min.

[0017] The main technical effects achieved by the embodiments of the present disclosure are: the deposition rate is 5-8 kg / min, and these parameters are determined based on the cooling rate and density requirements of the alloy ingot. The appropriate deposition rate and thickness help to form a uniform alloy ingot, reduce material waste, and improve the yield.

[0018] Optionally, during the deposition of the small alloy particles, the collector moves at a speed of 0.5 to 1.5 m / s to control the deposition thickness and form a uniform alloy ingot.

[0019] The main technical effect achieved by the embodiment of the present disclosure is that the collector moves at a speed of 0.5 to 1.5 m / s, and this speed range is determined based on the deposition dynamics of the small alloy particles. The appropriate movement speed can control the deposition of the small alloy particles, ensure the uniformity and quality of the alloy ingot, and improve the consistency of subsequent processing.

[0020] Optionally, before the alloy melt flows into the atomizer, the temperature of the spray forming equipment is adjusted to 900° C. to 950° C.

[0021] The main technical effect achieved by the embodiment of the present disclosure is that the temperature of the spray forming equipment is adjusted to 900°C to 950°C, and this temperature range is determined based on the atomization and solidification characteristics of the alloy melt. The appropriate temperature is conducive to the atomization and rapid solidification of the alloy melt, avoiding overheating or uneven solidification, thereby obtaining uniform small alloy particles.

[0022] Optionally, in the process of atomizing the alloy solution into gaseous alloy small particles and spraying them out from the nozzle of the atomizer, the atomization pressure is 0.30 MPa for the first level and 1.20 MPa for the second level, the atomization angle is 10 degrees, and the atomization gas flow rate is 50-60 L / min.

[0023] The main technical effects achieved by the embodiments of the present disclosure are: the atomizing gas flow rate is 50-60 L / min, and the atomizing angle is 10 degrees, and these parameters are determined based on the atomizing efficiency and the flight trajectory of the alloy small particles. Appropriate gas flow rate and atomizing angle help to uniformly atomize the alloy melt and increase the cooling rate of the alloy small particles, thereby obtaining a fine and uniform grain structure.

[0024] Optionally, the copper alloy is subjected to aging treatment after rolling forming, specifically, aging treatment is performed at 300° C. for 2-4 hours to reduce residual stress in the alloy and stabilize the microstructure of the alloy.

[0025] The main technical effects achieved by the embodiments of the present disclosure are: aging treatment helps to reduce residual stress in the alloy, improve the dimensional stability of the material, and reduce deformation during processing and use; by stabilizing the microstructure of the alloy, aging treatment improves the durability and fatigue resistance of the material.

[0026] Optionally, during the aging treatment, the alloy ingot is placed in a furnace with a controlled atmosphere of nitrogen or argon to prevent oxidation of the alloy surface during the aging treatment.

[0027] The main technical effects achieved by the embodiments of the present disclosure are: aging treatment in a furnace with a controlled atmosphere can prevent the alloy surface from oxidizing at high temperatures and maintain the surface smoothness and performance; the anti-oxidation treatment improves the corrosion resistance of the product, extends the service life of the product, and enhances the market competitiveness of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The figure is a schematic flow chart of a method for preparing a copper alloy by spray forming in one embodiment of the present disclosure. DETAILED DESCRIPTION

[0029] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The modes described in the following exemplary embodiments do not represent all modes consistent with the present disclosure. Instead, they are merely examples of devices consistent with some aspects of the present disclosure as detailed in the appended claims.

[0030] The terms used in the present disclosure are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure. Unless otherwise defined, the technical terms or scientific terms used in the present disclosure should be understood by people with ordinary skills in the field to which the present disclosure belongs. The words "first", "second" and similar words used in the present disclosure specification and claims do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, similar words such as "one" or "one" do not indicate a quantitative limitation, but indicate that there is at least one, and if only "one" is referred to, it will be separately described. "Multiple" or "several" means two or more. Unless otherwise specified, similar words such as "front", "rear", "lower" and / or "upper" are only for the convenience of explanation, and are not limited to one position or one spatial orientation. Similar words such as "include" or "comprise" mean that the elements or objects appearing in front of "include" or "comprise" cover the elements or objects listed after "include" or "comprise" and their equivalents, and do not exclude other elements or objects. "Connected" or "connected" and similar words are not limited to physical or mechanical connections, and may include electrical connections, whether direct or indirect. The singular forms of "a", "an", "the" and "the" used in this disclosure and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0031] like Figure 1 As shown, a first aspect of an embodiment of the present disclosure provides a spray forming method for preparing a copper alloy, the spray forming method comprising:

[0032] After the copper alloy material raw material is heated and melted into alloy melt, it is transferred to the funnel of the spray forming equipment so that the alloy melt flows into the atomizer;

[0033] The high-pressure nitrogen atomization process atomizes the alloy melt into gaseous alloy small particles and sprays them out from the nozzle of the atomizer;

[0034] Before the alloy particles are completely solidified, they are deposited on a collector and form an alloy ingot.

[0035] High-pressure inert gas is used to atomize the metal liquid flow into fine droplets, and the gas pressure and flow rate, as well as the diameter of the nozzle, are controlled. The diameter of the fine droplets is generally at the micron level, which can increase the surface area of ​​the droplets and increase their cooling rate; the atomized metal droplets will fly along the axis of the nozzle at a very high speed, and the structure of the nozzle and the initial velocity of the droplets are controlled. The droplets flying at high speed will experience strong cooling and solidification during the flight, thus forming the characteristics of rapid solidification structure; before the droplets are completely solidified, they are deposited on the collector; the structure and position of the collector are controlled so that the droplets can be evenly deposited on the collector. In the preparation process, the problem of segregation is suppressed by controlling the cooling rate and the temperature gradient during the deposition process, and optimizing the nozzle structure, gas pressure and flow rate and other parameters, so as to prepare a blank with uniform composition; due to the rapid solidification characteristics of the spray forming technology, the segregation problem in the preparation process of copper alloy can be significantly improved and energy consumption and cost can be reduced. Through the above technical means, copper alloy blanks with refined grain structure and uniform composition can be prepared, and verified by performance testing and quality inspection of the final product.

[0036] As an optional embodiment, the copper alloy material raw material includes copper Cu, nickel Ni and tin Sn, and is mixed in a weight ratio of 73-81 parts of copper Cu, 13-17 parts of nickel Ni and 6-10 parts of tin Sn. The addition of nickel improves the strength and corrosion resistance of the alloy, while the addition of tin improves the casting performance and cutting performance of the alloy.

[0037] As an optional implementation, the alloy melt is heated and melted in an inert gas-protected medium frequency furnace before being transferred to the funnel of the spray forming equipment, wherein the power of the medium frequency furnace is 200-300kW and the heating rate is controlled at 10-20°C / min. Heating and melting in an inert gas-protected medium frequency furnace reduces oxidation of the alloy during the melting process, maintains the purity of the alloy, and improves the corrosion resistance and electrical conductivity of the material; controlling the heating rate helps to uniformly heat the alloy melt and reduce material defects caused by local overheating or uneven heating.

[0038] As an optional embodiment, the inner wall of the funnel of the spray forming equipment is coated with an anti-adhesion coating, the coating material is Teflon, and the thickness is 0.1 to 0.3 mm. The anti-adhesion coating reduces the adhesion of the alloy melt to the inner wall of the funnel, reduces the need for cleaning, and improves production efficiency; the wear resistance and heat resistance of the Teflon coating help to extend the service life of the spray forming equipment.

[0039] As an optional embodiment, during the deposition of the alloy small particles, the deposition rate is 5 to 8 kg / min. The deposition rate is 5 to 8 kg / min, and these parameters are determined based on the cooling rate and density requirements of the alloy ingot. Appropriate deposition rate and thickness help to form a uniform alloy ingot, reduce material waste, and improve the yield.

[0040] As an optional embodiment, during the deposition of small alloy particles, the collector moves at a speed of 0.5 to 1.5 m / s to control the deposition thickness and form a uniform alloy ingot. The collector moves at a speed of 0.5 to 1.5 m / s, and this speed range is determined based on the deposition dynamics of small alloy particles. The appropriate movement speed can control the deposition of small alloy particles, ensure the uniformity and quality of the alloy ingot, and improve the consistency of subsequent processing.

[0041] As an optional embodiment, before the alloy melt flows into the atomizer, the temperature of the spray forming equipment is adjusted to 900°C to 950°C. The temperature of the spray forming equipment is adjusted to 900°C to 950°C, and this temperature range is determined based on the atomization and solidification characteristics of the alloy melt. The appropriate temperature helps the atomization and rapid solidification of the alloy melt, avoids overheating or uneven solidification, and thus obtains uniform small alloy particles.

[0042] As an optional embodiment, in the process of atomizing the alloy solution into gaseous alloy small particles and ejecting them from the nozzle of the atomizer, the atomization pressure is 0.30Mpa for the first level and 1.20Mpa for the second level, the atomization angle is 10 degrees, and the atomization gas flow rate is 50-60L / min. The atomization gas flow rate is 50-60L / min, and the atomization angle is 10 degrees. These parameters are determined based on the atomization efficiency and the flight trajectory of the alloy small particles. Appropriate gas flow rate and atomization angle contribute to the uniform atomization of the alloy melt and increase the cooling rate of the alloy small particles, thereby obtaining a fine and uniform grain structure.

[0043] As an optional implementation, the copper alloy is subjected to aging treatment after rolling, specifically aging treatment at 300°C for 2-4 hours to reduce residual stress in the alloy and stabilize the microstructure of the alloy. Aging treatment helps to reduce residual stress in the alloy, improve the dimensional stability of the material, and reduce deformation during processing and use; by stabilizing the microstructure of the alloy, aging treatment improves the durability and fatigue resistance of the material.

[0044] As an optional embodiment, during the aging treatment, the alloy ingot is placed in a furnace with a controlled atmosphere of nitrogen or argon to prevent oxidation of the alloy surface during the aging treatment. Aging treatment in a furnace with a controlled atmosphere can prevent oxidation of the alloy surface at high temperatures and maintain surface finish and performance; the treatment to prevent oxidation improves the corrosion resistance of the product, extends the service life of the product, and enhances the market competitiveness of the product.

[0045] The technical solution of the present invention will be further described below in conjunction with specific embodiments.

[0046] Example 1

[0047] Steps:

[0048] Copper Cu, nickel Ni and tin Sn raw materials are mixed according to the weight ratio of copper Cu81, nickel Ni13 and tin Sn6 to prepare alloy material raw materials.

[0049] The mixed alloy material raw materials are added into a medium frequency furnace, heated to 1050°C at a heating rate of 15°C / min, and melted into an alloy melt.

[0050] The alloy melt was transferred to the funnel of the spray forming equipment, and the equipment temperature was adjusted to 925°C so that the alloy melt flowed into the atomizer.

[0051] The alloy melt was atomized by high-pressure nitrogen atomization process, with a first-level atomization pressure of 0.35 MPa, a second-level atomization pressure of 1.10 MPa, an atomization angle of 10 degrees, and an atomization gas flow rate of 55 L / min.

[0052] Before the alloy particles are completely solidified, they are deposited onto a collector moving at a speed of 1.0 m / s, with a deposition rate of 6 kg / min.

[0053] Results and analysis:

[0054] The obtained copper alloy ingot has uniform grain structure without obvious macro-segregation, and the grain size is about 25-36 μm, showing a good microstructure.

[0055] Example 2

[0056] Steps:

[0057] Copper Cu, nickel Ni and tin Sn raw materials are mixed according to the weight ratio of copper Cu77, nickel Ni15 and tin Sn8 to prepare alloy material raw materials.

[0058] The mixed alloy material raw materials are added into a medium frequency furnace, heated to 1020° C. at a heating rate of 12° C. / min, and melted into an alloy melt.

[0059] The alloy melt was transferred to the funnel of the spray forming equipment, and the equipment temperature was adjusted to 940°C so that the alloy melt flowed into the atomizer.

[0060] The alloy melt was atomized by high-pressure nitrogen atomization process, with a first-level atomization pressure of 0.32 MPa, a second-level atomization pressure of 1.15 MPa, an atomization angle of 10 degrees, and an atomization gas flow rate of 58 L / min.

[0061] Before the alloy particles are completely solidified, they are deposited onto a collector moving at a speed of 0.8 m / s, with a deposition rate of 7 kg / min.

[0062] Results and analysis:

[0063] The grain size of the copper alloy ingot is slightly finer than that of Example 1, about 20 to 30 μm on average, with no obvious macro-segregation, showing a more uniform microstructure.

[0064] Example 3

[0065] Steps:

[0066] Copper Cu, nickel Ni and tin Sn raw materials are mixed according to the weight ratio of copper Cu73, nickel Ni17 and tin Sn10 to prepare alloy material raw materials.

[0067] The mixed alloy material raw materials are added into a medium frequency furnace, heated to 1040°C at a heating rate of 18°C / min, and melted into an alloy melt.

[0068] The alloy melt was transferred to the funnel of the spray forming equipment, and the equipment temperature was adjusted to 910°C so that the alloy melt flowed into the atomizer.

[0069] The alloy melt was atomized by high-pressure nitrogen atomization process, with a first-level atomization pressure of 0.31 MPa, a second-level atomization pressure of 1.20 MPa, an atomization angle of 10 degrees, and an atomization gas flow rate of 50 L / min.

[0070] Before the alloy particles are completely solidified, they are deposited onto a collector moving at a speed of 0.9 m / s, with a deposition rate of 5.5 kg / min.

[0071] Results and analysis:

[0072] The grain size of the copper alloy ingot is about 25 to 32 μm, with no obvious macro-segregation.

[0073] The above are only preferred embodiments of the present disclosure and are not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present disclosure should be included in the scope of protection of the present disclosure.

Claims

1. A method for preparing a copper alloy by spray forming, characterized in that: The spray forming method comprises: After the copper alloy material raw material is heated and melted into alloy melt, it is transferred to the funnel of the spray forming equipment so that the alloy melt flows into the atomizer; The high-pressure nitrogen atomization process atomizes the alloy melt into gaseous alloy small particles and sprays them out from the nozzle of the atomizer; Before the alloy particles are completely solidified, they are deposited on a collector and form an alloy ingot.

2. The method for preparing a copper alloy by spray forming according to claim 1, characterized in that: The copper alloy material raw materials include copper Cu, nickel Ni and tin Sn, and are mixed in a weight ratio of 73-81 parts of copper Cu, 13-17 parts of nickel Ni and 6-10 parts of tin Sn.

3. The method for preparing a copper alloy by spray forming according to claim 1, characterized in that: Before being transferred to the funnel of the injection molding equipment, the alloy melt is heated and melted in a medium frequency furnace protected by inert gas, wherein the power of the medium frequency furnace is 200-300kW and the heating rate is controlled at 10-20°C / min.

4. The method for preparing a copper alloy by spray forming according to claim 1, characterized in that: The inner wall of the funnel of the injection molding equipment is coated with an anti-adhesion coating, and the thickness of the anti-adhesion coating is 0.1-0.3 mm.

5. The method for preparing a copper alloy by spray forming according to claim 1, characterized in that: During the deposition of the alloy small particles, the deposition rate is 5-8 kg / min.

6. The method for preparing a copper alloy by spray forming according to claim 1, characterized in that: During the deposition of the alloy small particles, the collector moves at a speed of 0.5-1.5 m / s to control the deposition thickness and form a uniform alloy ingot.

7. The method for preparing a copper alloy by spray forming according to claim 1, characterized in that: Before the alloy melt flows into the atomizer, the temperature of the spray forming equipment is adjusted to 900°C to 950°C.

8. The method for preparing a copper alloy by spray forming according to claim 1, characterized in that: In the process of the alloy solution being atomized into gaseous alloy small particles and sprayed out from the nozzle of the atomizer, the atomization pressure is 0.30 MPa for the first level and 1.20 MPa for the second level, the atomization angle is 10 degrees, and the atomization gas flow rate is 50-60 L / min.

9. The method for preparing a copper alloy by spray forming according to claim 1, characterized in that: The copper alloy is subjected to aging treatment after rolling and forming, specifically, aging treatment is carried out at 300° C. for 2-4 hours to reduce residual stress in the alloy and stabilize the microstructure of the alloy.

10. The method for preparing a copper alloy by spray forming according to claim 9, characterized in that: During the aging treatment, the alloy ingot is placed in a furnace with a controlled atmosphere of nitrogen or argon to prevent oxidation of the alloy surface during the aging treatment.

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