CN103433500A - Preparation method of high-purity micro-fine low-oxygen titanium powder - Google Patents

Abstract

The invention provides a method for preparing high-purity fine low-oxygen titanium powder, which belongs to the technical field of powder making in powder metallurgy technology. It is characterized in that hydrogenation dehydrogenation is combined with jet milling process. Firstly, titanium sponge is hydrogenated to produce titanium hydride powder, and then titanium hydride is crushed by jet mill, followed by vacuum dehydrogenation, and finally crushed by jet mill. Classification and vacuum packaging to obtain titanium powder products. Compared with the traditional ball milling process, the jet milling process is non-polluting and can avoid iron impurities caused by the collision of steel balls during the ball milling process. The jet milling and high vacuum dehydrogenation treatment can control the oxygen content to the minimum, and the powder extraction and packaging operations are all within Carried out in the glove box. Therefore, the powder is isolated from the air during the whole process, and high-purity fine low-oxygen titanium powder is obtained.

Description

A kind of preparation method of high-purity micro-fine low-oxygen titanium powder

technical field

The invention relates to a preparation technology of titanium powder, which belongs to the technical field of powder making in powder metallurgy technology, and in particular provides a preparation method of high-purity, microfine and low-oxygen titanium powder.

technical background

Titanium and its alloys have properties such as low density, high specific strength, good corrosion resistance, and excellent biocompatibility, and have broad application prospects in aviation, aerospace, military, medical, automotive, sports and leisure industries. However, due to the high production cost at present, the real application is still limited to high-end fields such as aerospace. Casting is the most commonly used preparation technology for titanium alloys. Due to the long process route and low material utilization rate, the cost cannot meet the requirements of the civilian field. Therefore, the development of low-cost titanium preparation technology is very important for the civilian use of titanium.

Powder metallurgy is a process technology that uses metal powder as raw material to manufacture metal materials through forming and sintering. The use of powder metallurgy to produce titanium alloys can greatly reduce material consumption and machining costs. In recent years, with the continuous development of the low-cost trend of titanium, the research work of powdered titanium alloy has attracted widespread attention from academia and industry. When producing powdered titanium alloys, the preparation of high-quality powder raw materials is particularly important, especially the control of powder oxygen content has a great impact on the performance of the final product, so the development of low-oxygen titanium powder preparation technology has become a key issue for powdered titanium alloys.

At present, the production of titanium powder mainly adopts the HDH process. Firstly, the sponge titanium is hydrogenated, then the brittle titanium hydride powder is crushed, and finally the titanium powder is obtained by vacuum dehydrogenation and crushing. In the above production process, the powder will be exposed to the air for a part of the time, such as hydrogenation out of the furnace, ball mill out of the tank, dehydrogenation out of the furnace, vacuum packaging, etc., especially the fine powder after ball milling and dehydrogenation, the surface is easily oxidized, resulting in Powder oxygen content is difficult to meet the requirements. Therefore, oxygen control in the above process is the focus and difficulty in the preparation of low-oxygen titanium powder. The patent No. 200810187634.7 has been retrieved to provide a new HDH low-oxygen high-purity titanium powder production process. This invention adds an oxygen-reducing agent during the hydrodehydrogenation process and implements full air humidity control during the production process to produce High-quality titanium powder products with low oxygen content, the -60 mesh titanium powder produced by this invention has an oxygen content of 0.15%. Through the above measures, the oxygen increase in the process of titanium powder bursting is reduced, but it is still insufficient from the results. The -60 mesh titanium powder is very coarse, and it is difficult to densify during the sintering process. In addition, when the particle size of titanium powder produced by this process is reduced to -325 mesh or even -500, the oxygen content will increase greatly, and it will be difficult to meet the low oxygen requirements. Therefore, how to ensure low oxygen content while obtaining fine titanium powder is the key to solving the problem.

Contents of the invention

The purpose of the present invention is to solve the problem of oxygenation caused by titanium powder bursting in the HDH process, prepare high-purity, fine, low-oxygen titanium powder, and provide high-quality raw materials for the preparation of high-performance powder titanium alloys. High-purity micro-fine low-oxygen titanium powder is prepared by combining hydrogenation dehydrogenation and jet milling, and jet milling is used instead of rolling or vibrating ball milling in traditional processes. The collision force of the inner wall is very small, the inner wall has no wear, no foreign matter enters the material, no pollution, and can produce high-purity powder; on the other hand, after the working gas of the jet mill is injected into the crushing chamber through the nozzle, the gas breaker rapidly expands and absorbs a large amount of dust. Heat, which can absorb the heat generated by the collision of powder particles, does not produce temperature rise, and is beneficial to prevent powder oxidation. In addition, a powder modifier with superfluidity can be added at the feed inlet, so that the surface of the powder particles is covered with an isolation film to isolate the particles from oxygen. Finally, the glove box is connected to the jet mill equipment and the dehydrogenation furnace equipment, and the powder is packaged in the glove box after the powder is prepared, so as to control the powder from being in contact with the air during the whole preparation process and control the oxygen content of the powder to a minimum .

This technology first hydrogenates sponge titanium to produce titanium hydride powder, then crushes titanium hydride by jet mill, then dehydrogenates it in vacuum, and finally uses jet mill for crushing and classification, and vacuum packaging to obtain high-purity fine particles of different particle sizes. Low oxygen titanium powder.

Based on above-mentioned purpose and principle, concrete technique of the present invention is as follows:

1. Hydrogenate sponge titanium at 480-750°C and 0.1-0.3MPa high-purity hydrogen pressure for 5-10 hours to obtain coarse-grained hydrogenated titanium with a particle size of 100-500 μm; the sponge titanium is required to be grade 1 sponge titanium, oxygen Content<0.08wt.%;

2. Jet-milling the above-mentioned coarse-grained titanium hydride powder under high-purity argon pressure conditions of 0.3-0.7 MPa to obtain titanium hydride with an average particle size of 10-100 μm;

3. Vacuum dehydrogenate the jet-milled titanium hydride at 600-750°C for 4-12 hours to obtain titanium powder;

4. Jet mill the titanium powder under the pressure condition of 0.3-0.7MPa high-purity argon gas to obtain titanium powder;

5. Vacuum-encapsulate the above-mentioned titanium powder to obtain high-purity micro-fine low-oxygen titanium powder.

The titanium powder has a purity of up to 99.7%, an average particle size of 20-75 μm, and an oxygen content of 0.12-0.15wt.%.

The invention combines the hydrogen crushing (HD) process with the jet mill, utilizes the advantages of no pollution, less oxidation, and uniform particle size in the jet mill process to solve the oxidation and pollution problems in the traditional ball milling process, and at the same time takes powder and products in the glove box Encapsulation, to minimize the oxygen content of titanium powder, compared with the traditional process, its advantages are:

1) The purity of titanium powder is high: the traditional process uses ball milling to crush the powder. The steel ball will increase the content of impurities such as iron in the titanium powder during the collision process, while the jet mill uses the high-energy collision of the material itself to pulverize. The material and the jet mill chamber The wall collision force is very small, the inner wall is not worn, and no foreign matter enters the material, so the purity is high;

2) The oxygen content of titanium powder is low: the present invention carries out oxygen control treatment from three aspects, one is to use high-purity argon protection during the jet mill, and add a modifier to coat the powder surface with an isolation layer, and the other is to use high vacuum to remove The hydrogen furnace is used for dehydrogenation treatment, and the third is to carry out powder extraction and packaging treatment in the glove box to reduce the oxygen content of titanium powder to a minimum.

Detailed ways

Embodiment 1: prepare the titanium powder of 200 orders, oxygen content 0.12wt.%

1. Hydrogenate grade 1 titanium sponge with an oxygen content of 0.75wt.% at 480°C and 0.1MPa high-purity hydrogen pressure for 10 hours to obtain coarse titanium hydride with an average particle size of 500μm;

2. The above-mentioned titanium hydride powder is subjected to jet milling under the pressure of 0.3MPa high-purity argon to obtain titanium hydride with an average particle size of 100 μm;

3. Vacuum dehydrogenate the jet-milled titanium hydride at 600°C for 12 hours to obtain titanium powder;

4. Jet milling the titanium powder under the pressure of 0.3MPa high-purity argon gas to obtain titanium powder with a purity of 99.7%, an average particle size of 75 μm (200 mesh), and an oxygen content of 0.12wt.%.

5. Vacuum-encapsulate the above-mentioned titanium powder to obtain high-purity micro-fine low-oxygen titanium powder.

Embodiment 2: prepare the titanium powder of 325 orders, oxygen content 0.13wt.%

1. Hydrogenate grade 1 titanium sponge with an oxygen content of 0.75wt.% at 600°C and 0.2MPa high-purity hydrogen pressure for 8 hours to obtain coarse titanium hydride with an average particle size of 350μm;

2. Jet-milling the above-mentioned titanium hydride powder under 0.5MPa high-purity argon pressure to obtain titanium hydride with an average particle size of 75 μm;

3. Vacuum dehydrogenate the jet-milled titanium hydride at 650°C for 10 hours to obtain titanium powder;

4. Jet milling the titanium powder under the pressure of 0.5MPa high-purity argon to obtain titanium powder with a purity of 99.7%, an average particle size of 45 μm (325 mesh), and an oxygen content of 0.13wt.%.

5. Vacuum-encapsulate the above-mentioned titanium powder to obtain high-purity micro-fine low-oxygen titanium powder.

Embodiment 3: prepare the titanium powder of 500 orders, oxygen content 0.14wt.%

1. Hydrogenate grade 1 titanium sponge with an oxygen content of 0.75wt.% at 700°C and 0.25MPa hydrogen pressure for 7 hours to obtain coarse titanium hydride with a particle size of 200μm;

2. Jet milling the above-mentioned titanium hydride powder under the pressure condition of 0.6 MPa high-purity argon to obtain titanium hydride with an average particle size of 45 μm;

3. Vacuum dehydrogenate the jet-milled titanium hydride at 700°C for 8 hours to obtain titanium powder;

4. Jet milling the titanium powder under 0.6MPa high-purity argon pressure condition to obtain titanium powder with a purity of 99.7%, an average particle size of 30 μm (500 mesh), and an oxygen content of 0.14wt.%.

5. Vacuum-encapsulate the above-mentioned titanium powder to obtain high-purity micro-fine low-oxygen titanium powder.

Example 4: Preparation of titanium powder with an average particle size of 20 μm and an oxygen content of 0.15wt.%.

1. Hydrogenate grade 1 titanium sponge with an oxygen content of 0.75wt.% at 750°C and 0.3MPa hydrogen pressure for 5 hours to obtain coarse titanium hydride with a particle size of 100μm;

2. Jet-milling the above-mentioned titanium hydride powder under the pressure condition of 0.7MPa high-purity argon to obtain titanium hydride with an average particle size of about 10 μm;

3. Vacuum dehydrogenate the jet-milled titanium hydride at 750°C for 4 hours to obtain titanium powder;

4. The titanium powder was subjected to jet milling under the pressure of 0.7MPa high-purity argon gas to obtain titanium powder with a purity of 99.7%, an average particle size of 20 μm, and an oxygen content of 0.15wt.%.

5. Vacuum-encapsulate the above-mentioned titanium powder to obtain high-purity micro-fine low-oxygen titanium powder.

Claims (4)

1. A preparation method of high-purity micro-fine low-oxygen titanium powder, characterized in that the preparation steps are as follows: 1) Hydrogenate sponge titanium at 480-750°C and 0.1-0.3MPa high-purity hydrogen pressure for 5-10 hours to obtain coarse-grained hydrogenated titanium with a particle size of 100-500 μm; the sponge titanium is required to be grade 1 sponge titanium, oxygen Content<0.08wt.%; 2) Jet milling the above coarse titanium hydride powder under the pressure of 0.3-0.7MPa high-purity argon to obtain titanium hydride with an average particle size of 10-100 μm; 3) vacuum dehydrogenate the jet-milled titanium hydride at 600-750°C for 4-12 hours to obtain titanium powder; 4) Jet milling the titanium powder under the pressure of 0.3-0.7MPa high-purity argon gas to obtain titanium powders with different particle sizes and oxygen content specifications; 5) Vacuum-encapsulate the above-mentioned titanium powder to obtain a high-purity fine low-oxygen titanium powder product. 2. A method for preparing high-purity fine low-oxygen titanium powder according to claim 1, characterized in that: the purity of the titanium powder reaches 99.7%. 3. A method for preparing high-purity micro-low oxygen titanium powder according to claim 1, characterized in that: the average particle size of said titanium powder is 20-75 μm. 4. The method for preparing high-purity micro-fine low-oxygen titanium powder according to claim 1, characterized in that: the oxygen content of the titanium powder is 0.12-0.15wt.%.