Preparation method of titanium-containing alloy spherical powder of low-cost and large-diameter electrode

Abstract

The invention discloses a preparation method of titanium-containing alloy spherical powder with a low-cost and large-diameter electrode, and relates to the technical field of titanium-containing alloy powder materials.The preparation method comprises the following steps that 1, a mother alloy bar is prepared, and the end of the mother alloy bar is heated; 2, molten first metal liquid drops or first beam currents are obtained; and 3, a composite atomization method is adopted, the molten first metal liquid drops or the first beam currents are treated, airflow impacts the first metal liquid drops or the first beam currents, second metal liquid drops are obtained, the size of the second metal liquid drops is smaller than that of the first metal liquid drops, the second metal liquid drops fall and are solidified under atmosphere protection, and the metal powder is prepared.

Description

Technical Field

[0001] The invention relates to the technical field of titanium alloy powder materials, and in particular to a method for preparing low-cost, large-diameter titanium alloy spherical powder for electrodes. Background Art

[0002] Due to the development of additive manufacturing, cladding, powder metallurgy and other fields, nearly spherical powders containing titanium alloys are needed. However, the existing powder making methods are difficult to achieve low-cost, high-quality preparation of titanium alloy powders for the following reasons:

[0003] Titanium, as an active element, is prone to chemical reactions with ceramic crucibles. It cannot be powdered by atomization using a crucible, and cannot come into contact with water or other media. Therefore, vacuum induction melting gas atomization (VIGA) and water atomization with a crucible are not suitable for use.

[0004] The raw material of plasma wire atomization equipment (PA) must be wire, the raw material of radio frequency plasma spheroidization method must be powder, and methods such as plasma rotating electrode atomization (PREP) need to be pre-processed into round rods and made into threads. These methods have more requirements on the shape of the raw materials, increase the cost, and put forward higher requirements on the material processability and other aspects, affecting the yield rate.

[0005] Crucible-free vacuum electrode induction melting gas atomization (EIGA) does not contact the crucible, and the diameter of the master alloy electrode rod is usually 50mm, which will not cause reaction or introduce impurities. Therefore, alloy powder containing active elements can be prepared, but the cost is relatively high. The cost accounting is shown in the table. Based on the cost of raw materials, it currently mainly relies on gas recovery and reuse, peak electricity consumption, human resources and other aspects to reduce costs, which is difficult to reduce more significantly, which also affects the promotion and use of the metal powder back-end market.

[0006] In addition, more effective methods are urgently needed to prepare metal powder at low cost using recycled titanium alloy materials as raw materials. Summary of the invention

[0007] The purpose of the present invention is to overcome the deficiencies of the prior art and to provide a method for preparing titanium alloy powder for large-diameter electrodes at low cost.

[0008] In order to achieve the above-mentioned object, the present invention adopts the following technical solution: In order to achieve the above-mentioned object, the present invention adopts the following technical solution:

[0009] A method for preparing a titanium alloy spherical powder for a low-cost, large-diameter electrode comprises the following steps:

[0010] Step 1: preparing a master alloy bar and heating the end of the master alloy bar;

[0011] Step 2: obtaining a molten first metal droplet or a first stream;

[0012] Step 3: The molten first metal droplets or the first beam are processed by a composite atomization method, and the airflow impacts the first metal droplets or the first beam to obtain second metal droplets, wherein the size of the second metal droplets is smaller than that of the first metal droplets, and the second metal droplets fall and solidify under the protection of the atmosphere to obtain metal powder.

[0013] In some embodiments, step 3 comprises the following steps:

[0014] S1. Use a master alloy bar of preset diameter as an electrode, place it in a vacuum environment, and then fill it with inert gas;

[0015] S2, using an induction heating method to heat and melt the end of the master alloy bar as an electrode to form a first metal droplet or a first beam with a size of millimeters;

[0016] S3. A gas atomization method is adopted, and the powder particle size range is 5μm to 150μm. A supersonic spray disk is adopted, and a liquid guide tube is provided in the spray disk. The first metal droplets or the first beam passing through the spray disk during the dripping process are impacted by an inert gas, so that the first metal droplets form second metal droplets in the micrometer range. The second metal droplets in the container move and solidify under the multiple effects of gravity and airflow to obtain the metal powder.

[0017] In step S1, the vacuum degree of the vacuum environment is 10 -1 Pa~10 -6 Pa;

[0018] The inert gas in step S1 includes at least one of argon and helium;

[0019] The front end cone shape of the master alloy bar in step S1 is 10° to 170°;

[0020] The heating and melting temperature in step S2 is 190°C to 3150°C;

[0021] The power of the power source in step S2 is 30kW to 1000kW;

[0022] The number of turns of the conical induction coil in step S2 is 1 to 10;

[0023] The inert gas consumption in step S3 is 50m 3 / h~2000m 3 / h.

[0024] The gas pressure during atomization in step S2 is 0.1 MPa to 15 MPa, and the atomization time is ≥ 1 s.

[0025] In some embodiments, the preparation of the master alloy bar comprises at least one of the following two methods:

[0026] The master alloy bar is smelted by vacuum consumable arc furnace smelting method (VAR method), non-consumable vacuum arc furnace smelting method (NC method), cold hearth smelting method (CHM method), cold crucible smelting method (CCM method), and electroslag smelting method (ESR method).

[0027] In some embodiments, the titanium alloy powder has an oxygen increment of 0.0001 ppm to 1000 ppm compared to the master alloy rod used for powder preparation.

[0028] In some embodiments, in S1, the diameter of the master alloy bar with a preset diameter is not less than 85 mm and not more than 300 mm.

[0029] The beneficial effects that may be brought about by the method for preparing a titanium alloy spherical powder for a low-cost, large-diameter electrode disclosed in this application include but are not limited to:

[0030] (1) The metal powder prepared by the present invention has significantly reduced cost.

[0031] (2) The preparation method of the present invention can effectively avoid harmful chemical reactions, reduce pollution, lower oxygen content, and improve powder quality.

[0032] (3) The raw materials required in the preparation method of the present invention can be recycled materials, which further effectively reduces the production cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a diagram of an electrode rod material with a diameter of 150 mm being melted into a droplet according to the present invention;

[0034] Figure 2 This is a beam flow diagram of an electrode rod material with a diameter of 150 mm melted in the present invention;

[0035] Figure 3 This is an optical microscope photo of pure titanium powder in Example 3 of the present invention DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solution and advantages of the present application more clear, the present application is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described here are only used to explain the present application and are not used to limit the present application.

[0037] On the contrary, the present application covers any substitution, modification, equivalent method and scheme made on the essence and scope of the present application as defined by the claims. Further, in order to make the public have a better understanding of the present application, some specific details are described in detail in the detailed description of the present application below. Those skilled in the art can fully understand the present application without the description of these details.

[0038] The following is a detailed description of a method for preparing a low-cost, large-diameter electrode-containing titanium alloy spherical powder according to an embodiment of the present application. It should be noted that the following embodiments are only used to explain the present application and do not constitute a limitation on the present application.

[0039] like Figure 1-2 As shown, a titanium alloy spherical powder for low-cost, large-diameter electrodes is made of master alloy rods, and the diameter of the master alloy rods is not less than 85mm and not more than 300mm. The diameter of the master alloy rods used as electrodes is not less than 85mm and not more than 300mm. Matching the corresponding spray plate, power supply, mechanical structure and corresponding process, under the same master alloy rod length for electrodes, the single-furnace metal powder output of rods with a diameter of not less than 85mm is increased by more than 300% compared with the single-furnace metal powder output of rods with a diameter of 50mm, and the single-furnace metal powder output of rods with a diameter of 300mm is 36 times that of rods with a diameter of 50mm. Compared with the master alloy electrode rods used for powdering, the metal powder obtained by the present invention has an oxygen increment of 0.0001ppm to 1000ppm.

[0040] The present invention also claims a method for preparing the metal powder, comprising the following steps:

[0041] Metal ingots prepared by different smelting methods and metal rods after mechanical processing are used as master alloy raw materials for powder making, and metal powders are made by gas atomization method;

[0042] Preferably, the composite atomization method comprises the following steps:

[0043] S1. Use a vacuum pump to evacuate the furnace body first, so that the master alloy bar is in a vacuum environment, and then fill it with inert gas;

[0044] S2, using an induction heating method, firstly heating and melting the end of a large-diameter master alloy bar as an electrode to form a first metal droplet of millimeter size;

[0045] S3. Using an atomization method, the first metal droplets passing through the spray plate during the dripping process are impacted with an inert gas, so that the first metal droplets are formed into second metal droplets of micrometer size. The second metal droplets move and solidify in the container under the multiple effects of gravity and airflow to obtain the metal powder.

[0046] Preferably, the vacuum degree of the vacuum environment in step S1 is 10 -1 Pa~10 -6 Pa Pa.

[0047] Preferably, the inert gas in step S1 includes at least one of nitrogen, argon and helium.

[0048] Preferably, the purity of the inert gas in step S1 is 99.9%-99.99999%, and the vacuum and inert gas replacement are repeated ≥ 1 times.

[0049] Preferably, the heating and melting temperature in step S2 is 190°C to 3150°C.

[0050] Preferably, the gas pressure during atomization in step S3 is 0.1 MPa to 15 MPa, and the atomization time is ≥ 1 s. When the gas pressure during atomization is too high or the atomization time is too long, the content of introduced impurities will increase.

[0051] Preferably, the aerosolization time in step S3 is 50s to 1000000s. It can be understood that the aerosolization time includes but is not limited to 50s, 60s, 100s, 200s, 300s, 500s, 800s, 1000s, 10000s, 100000s, 1000000s.

[0052] Preferably, the master alloy bar is alloyed by vacuum consumable arc furnace melting method (VAR method), non-consumable vacuum arc furnace melting method (NC method), cold hearth melting method (CHM method), cold crucible melting method (CCM method), electroslag melting method (ESR method) and the like; the melting temperature of the alloy melting is, it can be understood that the melting temperature of the alloy melting includes but is not limited to.

[0053] The present invention also seeks to protect the use of the metal powder containing active metal elements in additive manufacturing, powder metallurgy, and cladding.

[0054] Matching the corresponding spray plate, power supply, mechanical structure and corresponding process, under the same electrode rod length, the metal powder output of a 100mm diameter rod is 4 times that of a 50mm diameter rod in a single furnace, and the metal powder output of a 300mm diameter rod is 36 times that of a 50mm diameter rod in a single furnace.

[0055] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. In the embodiments and comparative examples, the experimental methods used are conventional methods unless otherwise specified, and the materials, reagents, etc. used are all commercially available unless otherwise specified.

[0056] The content of active metal elements in the metal powders finally prepared in the embodiments of the present invention and the comparative examples is measured by conventional chemical quantitative methods in the art, and the oxygen increment and nitrogen increment are measured by an oxygen, nitrogen and hydrogen analyzer.

[0057] Example 1

[0058] See also Figure 1-2 , Powder making raw materials: titanium-tungsten alloy, composition: titanium atomic percentage 10at%, tungsten content 90at%, melting point 3150℃.

[0059] Preparation method:

[0060] S1. The raw materials are melted by vacuum consumable arc furnace melting method (VAR method) to obtain master alloy ingots, and master alloy rods with a diameter of 85 mm are obtained after mechanical processing, which are used as electrodes; the furnace body is evacuated by a vacuum pump to make the master alloy rods in a vacuum environment and filled with inert gas; wherein the vacuum degree is 10 -1 Pa, filled with argon gas with a purity of 99.9%, and replaced repeatedly at least once;

[0061] S2. The master alloy bar used as the electrode is melted by induction melting. The end of the master alloy bar is first heated and melted into liquid metal. The melting temperature is 3150°C, the power is 1000kW, and the number of turns of the conical induction coil is 10.

[0062] S3, the liquid metal flows into the atomizing spray plate through the guide device, and the inert gas impacts the liquid metal to form a droplet. The inert gas atomization pressure is 15MPa, the atomization duration is 10000s, and the metal powder is solidified in the container. The inert gas consumption is 2000m 3 / h.

[0063] The atomization pressure is 0.1MPa~15MPa, and the duration of atomization vibration is ≥1s; S4, atomizing the primary droplets formed by induction heating and melting to form secondary droplets by atomization method,

[0064] The obtained titanium-containing alloy powder has an oxygen increment of 1000 ppm compared with the master alloy electrode rod material used for powder preparation.

[0065] Example 2

[0066] See also Figure 1-2 , Powder making raw materials: titanium-rubidium alloy, composition: titanium atomic percentage 13at%, tungsten content 87at%, melting point 190℃.

[0067] Preparation method:

[0068] S1. The powder making raw materials are melted by non-consumable vacuum arc furnace melting method (NC method) to obtain master alloy ingots, and master alloy rods with a diameter of 300 mm are obtained after mechanical processing, which are used as electrodes; the furnace body is evacuated by a vacuum pump to make the master alloy rods in a vacuum environment and filled with inert gas; wherein the vacuum degree is 10 -6 Pa, filled with helium gas with a purity of 99.99999%, repeated replacement for 2 times;

[0069] S2. The master alloy bar material used as the electrode is melted by induction melting. The end of the master alloy bar material is first heated and melted into liquid metal. The melting temperature is 190°C, the power supply is 30kW, and the number of turns of the conical induction coil is 1;

[0070] S3, the liquid metal flows into the atomizing spray plate through the guide device, and the inert gas impacts the liquid metal to form a droplet. The inert gas atomization pressure is 0.1MPa, the atomization duration is 1s, and the metal powder is solidified in the container. The inert gas consumption is 50m 3 / h.

[0071] The atomization pressure is 0.1MPa~15MPa, and the duration of atomization vibration is ≥1s; S4, atomizing the primary droplets formed by induction heating and melting to form secondary droplets by atomization method,

[0072] The obtained titanium-containing alloy powder has an oxygen increment of 0.0001 ppm compared with the master alloy electrode rod material used for powder preparation.

[0073] Example 3

[0074] See also Figure 1-2 , Powder making raw material: pure titanium, composition: titanium atomic percentage 100at%, melting point 1668℃.

[0075] Preparation method:

[0076] S1. The raw materials are melted by cold hearth melting method (CHM method) to obtain master alloy ingots, and master alloy rods with a diameter of 150 mm are obtained after mechanical processing, which are used as electrodes; the furnace body is evacuated by a vacuum pump to place the master alloy rods in a vacuum environment and filled with inert gas; wherein the vacuum degree is 10 -3 Pa, filled with argon gas with a purity of 99.999%, and repeated replacement for 3 times;

[0077] S2. The master alloy bar used as the electrode is melted by induction melting. The end of the master alloy bar is first heated and melted into liquid metal. The melting temperature is 1900°C, the power is 200kW, and the number of turns of the conical induction coil is 4.

[0078] S3, the liquid metal flows into the atomizing spray plate through the guide device, and the inert gas impacts the liquid metal to form a droplet. The inert gas atomization pressure is 5MPa, the atomization duration is 300s, and the metal powder is solidified in the container. The inert gas consumption is 200m 3 / h.

[0079] The atomization pressure is 0.1MPa~15MPa, and the duration of atomization vibration is ≥1s; S4, atomizing the primary droplets formed by induction heating and melting to form secondary droplets by atomization method,

[0080] The obtained titanium-containing alloy powder has an oxygen increment of 100 ppm compared with the master alloy electrode rod material used for powder preparation.

Claims

1. A method for preparing a titanium alloy spherical powder for a low-cost, large-diameter electrode, characterized in that: The following steps are involved: Step 1: preparing a master alloy bar and heating the end of the master alloy bar; Step 2: obtaining a molten first metal droplet or a first stream; Step 3: The molten first metal droplets or the first beam are processed by a composite atomization method, and the airflow impacts the first metal droplets or the first beam to obtain second metal droplets, wherein the size of the second metal droplets is smaller than that of the first metal droplets, and the second metal droplets fall and solidify under the protection of the atmosphere to obtain metal powder.

2. The method for preparing a low-cost, large-diameter electrode-containing titanium alloy spherical powder according to claim 1, characterized in that: The step 3 comprises the following steps: S1. Use a master alloy bar of preset diameter as an electrode, place it in a vacuum environment, and then fill it with inert gas; S2, using an induction heating method to heat and melt the end of the master alloy bar as an electrode to form a first metal droplet or a first beam with a size of millimeters; S3. A gas atomization method is adopted, and the powder particle size range is 5μm to 150μm. A supersonic spray disk is adopted, and a liquid guide tube is provided in the spray disk. The first metal droplets or the first beam passing through the spray disk during the dripping process are impacted by an inert gas, so that the first metal droplets form second metal droplets in the micrometer range. The second metal droplets in the container move and solidify under the multiple effects of gravity and airflow to obtain the metal powder.

3. The method for preparing a low-cost, large-diameter titanium alloy spherical powder for electrodes according to claim 2, characterized in that: In step S1, the vacuum degree of the vacuum environment is 10 -1 Pa~10 -6 Pa; The inert gas in step S1 includes at least one of argon and helium; The front end cone shape of the master alloy bar in step S1 is 10° to 170°; The heating and melting temperature in step S2 is 190°C to 3150°C; The power of the power source in step S2 is 30kW to 1000kW; The number of turns of the conical induction coil in step S2 is 1 to 10; The inert gas consumption in step S3 is 50m 3 / h~2000m 3 / h.

4. The method for preparing a low-cost, large-diameter titanium alloy spherical powder for electrodes according to claim 3, characterized in that: The gas pressure during atomization in step S2 is 0.1 MPa to 15 MPa, and the atomization time is ≥ 1 s.

5. The method for preparing a low-cost, large-diameter titanium alloy spherical powder for electrodes according to claim 3, characterized in that: The preparation of the master alloy bar comprises at least one of the following two methods: The master alloy bar is smelted by vacuum consumable arc furnace smelting method (VAR method), non-consumable vacuum arc furnace smelting method (NC method), cold hearth smelting method (CHM method), cold crucible smelting method (CCM method), and electroslag smelting method (ESR method).

6. The method for preparing a low-cost, large-diameter titanium alloy spherical powder for electrodes according to claim 3, characterized in that: Compared with the master alloy rod used for powder preparation, the titanium alloy powder has an oxygen increment of 0.0001ppm to 1000ppm.

7. The method for preparing a low-cost, large-diameter titanium alloy spherical powder for electrodes according to claim 3, characterized in that: In S1, the diameter of the master alloy bar with a preset diameter is not less than 85 mm and not more than 300 mm.

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