Method for preparing foam titanium product by using titanium hydride powder

Abstract

The invention relates to the technical field of foam metal preparation, and discloses a method for preparing a foam titanium product by using titanium hydride powder, which comprises the following steps: 1) hydrogenating sponge titanium, crushing, sieving by 75-80 meshes, and taking the sieved titanium hydride powder as a raw material; (2) putting the raw materials into a prefabricated mold, vacuumizing to exhaust air, filling argon with a certain pressure, and carrying out compression molding to obtain a prefabricated blank; (3) the prefabricated blank is compacted in a low-pressure environment and subjected to high-temperature foaming, and a foam titanium crude product is obtained after high-temperature foaming is completed; (4) the foam titanium crude product is put into a hydrogen treatment furnace to be subjected to dehydrogenation treatment, and then a foam titanium product is obtained; the foamed titanium product is directly prepared from the titanium hydride powder, the middle titanium powder hydrogenation step is omitted, and the titanium powder utilization rate is increased; compared with high-temperature isostatic pressing forming, the low-pressure in-situ forming technology has the advantages of being small in pressure, short in forming time, low in temperature, energy-saving and efficient.

Description

Technical Field

[0001] The present invention relates to the technical field of preparation of metal foams, and particularly to a method for preparing titanium foam products using titanium hydride powder. Background Art

[0002] Titanium foam is a new type of porous metal structural functional material. Compared with porous materials made of materials such as stainless steel, copper, and aluminum, due to characteristics such as high specific strength, corrosion resistance, and good biocompatibility, metallic titanium has a series of unique application prospects. It is used as an adsorption material, a filter material, a catalyst carrier, and a metal electrode in the industrial field. In the medical field, due to its biocompatibility and porosity, it can be used to prepare biological implant materials such as bone joints. In the aerospace field, it is used as an energy absorption material for landing protection. Currently, the preparation processes of titanium foam include fiber sintering method, solidification method, compression-expansion method, 3D printing method, powder metallurgy sintering method, etc. Among them, the powder metallurgy method has simple process, low cost, and low equipment requirements, and can prepare titanium foam with controllable porosity and pore size. The main steps are raw material preparation: mixing titanium powder and pore-forming agent; pressing: putting the raw materials into a mold and pressing under temperature and pressure; high-temperature sintering; and cooling. Powder metallurgy generally makes holes inside the metal material by adding a pore-forming agent. Commonly used pore-forming agents include NaCl, NaF, K 2 CO 3 、CaCl 2 、ammonium bicarbonate, urea, methyl methacrylate, starch, etc. However, all pore-forming agents have different defects, and at the same time, the use of titanium powder has a relatively high price.

[0003] Therefore, in order to prepare titanium foam products with controllable pore size and porosity, low manufacturing cost, and batch production, it is urgent to develop a method for preparing titanium foam products using titanium hydride powder. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for preparing titanium foam products using titanium hydride powder to solve the above problems.

[0005] The solution of the present invention is

[0006] A method for preparing titanium foam products using titanium hydride powder, comprising the following steps:

[0007] 1) After the sponge titanium is hydrogenated, it is crushed and screened through 75-80 meshes, and the screened titanium hydride powder is used as the raw material;

[0008] 2) The raw material is placed in a prefabricated mold, the air is evacuated, and then argon gas is filled under a certain pressure, and it is pressed into shape to obtain a preform;

[0009] 3) The preform is compacted and foamed at high temperature in a low-pressure environment, and a rough titanium foam product is obtained after the high-temperature foaming is completed;

[0010] 4) The as - produced titanium foam rough product is put into a hydrogen treatment furnace for dehydrogenation treatment to obtain a titanium foam product.

[0011] As a preferred technical solution, the particle size of the screened titanium hydride powder is 40 - 200 microns.

[0012] As a preferred technical solution, the pre - fabricated mold is a steel sleeve.

[0013] As a preferred technical solution, the argon gas at a certain pressure in step 2) is argon gas with a pressure of 0.1 - 10 kPa.

[0014] As a preferred technical solution, in step 3), the low - pressure environment is 1 - 5 MPa, the temperature of the high - temperature foaming is 900 - 1000 °C, and the compaction time is 20 - 60 h.

[0015] As a preferred technical solution, in step 4), the dehydrogenation treatment is vacuum annealing for hydrogen removal, the temperature is 600 - 800 °C, and the time is 1 - 5 h.

[0016] Due to the adoption of a method for preparing titanium foam products using titanium hydride powder, 1) the sponge titanium is hydrogenated, crushed, and screened through 75 - 80 meshes to obtain the screened titanium hydride powder as the raw material; 2) the raw material is placed in a pre - fabricated mold, the air is evacuated, and then argon gas at a certain pressure is filled, and it is pressed into shape to obtain a pre - formed blank; 3) the pre - formed blank is compacted and subjected to high - temperature foaming in a low - pressure environment, and a titanium foam rough product is obtained after the high - temperature foaming is completed; 4) the titanium foam rough product is put into a hydrogen treatment furnace for dehydrogenation treatment to obtain a titanium foam product.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0018] The present invention is different from the conventional production method (using titanium powder, the production process of titanium powder itself is rather cumbersome and the production cost is high). Instead, the sponge titanium is directly hydrogenated, crushed, and screened to obtain titanium hydride powder within a certain particle size range as the raw material, without going through the dehydrogenation process and directly used as the raw material, reducing the preparation cost;

[0019] In the present invention, no pore - forming agent is added during pressing. It is placed in a pre - fabricated mold, the air is evacuated, and then argon gas at a certain pressure is filled to prevent contamination by oxygen in the air and pressed into shape. In this step, due to the relatively small filling pressure, it is different from the conventional production method and is not compacted but in a relatively loose state, waiting for foaming;

[0020] In the present invention, the pre - formed blank is subjected to high - temperature foaming in a low - pressure environment. The low pressure can ensure that the pre - formed blank is compacted for a certain time during the foaming process, and at the same time, the high temperature causes the titanium hydride powder to release hydrogen and foam. The low - pressure and high - temperature means that the pressure causes the powder to sinter within a certain volume and generate pores simultaneously.

[0021] Advantages of the present invention:

[0022] 1. The present invention directly prepares titanium foam products from titanium hydride powder, reduces the intermediate titanium powder hydrogenation step, and improves the utilization rate of titanium powder.

[0023] 2. The hydrogen released by the titanium hydride powder during the forming process in the present invention is used as a foaming agent, eliminating the need for additional addition of a foaming agent, saving the preparation cost and improving the purity of titanium foam.

[0024] 3. The present invention adopts a low-pressure in-situ forming technology. Compared with hot isostatic pressing at high temperature, it has the characteristics of small pressure, short forming time and low temperature, and is energy-saving and efficient. Specific embodiments

[0025] In order to make the technical means, creative features, achieved purposes and functions of the present invention easy to understand, the present invention will be further described below in conjunction with specific embodiments.

[0026] Example 1

[0027] The titanium hydride powder with a particle size of 40 microns was obtained by hydrogenating and crushing sponge titanium and used as the titanium powder raw material without going through the dehydrogenation process. Without adding a pore-forming agent, it was placed in a steel sleeve, evacuated and then filled with argon at 0.1 kPa. Then the titanium hydride powder was put into a hot isostatic pressing furnace for compaction and foaming. The temperature of hot isostatic pressing was 900 °C, the pressure was 1 MPa, and the compaction time was 20 hours. The foamed titanium foam was put into a hydrogen treatment furnace for vacuum annealing to remove hydrogen at a temperature of 600 °C for 1 hour, obtaining a titanium foam product with certain mechanical properties.

[0028] Example 2

[0029] The titanium hydride powder with a particle size of 200 microns was obtained by hydrogenating and crushing sponge titanium and used as the titanium powder raw material without going through the dehydrogenation process. Without adding a pore-forming agent, it was placed in a steel sleeve, evacuated and then filled with argon at 5 kPa. Then the titanium hydride powder was put into a hot isostatic pressing furnace for compaction and foaming. The temperature of hot isostatic pressing was 950 °C, the pressure was 3 MPa, and the compaction time was 40 hours. The foamed titanium foam was put into a hydrogen treatment furnace for vacuum annealing to remove hydrogen at a temperature of 700 °C for 3 hours, obtaining a titanium foam product with certain mechanical properties.

[0030] Example 3

[0031] Using hydrogenated titanium sponge that has been crushed and screened to obtain titanium hydride powder with a particle size of 100 microns as the raw material, without going through the dehydrogenation process, directly used as the titanium powder raw material, without adding a pore-forming agent, placed in a steel sleeve, evacuated and then filled with argon at 10 kPa, and then the titanium hydride powder is put into a hot isostatic pressing furnace for compaction and foaming. The temperature of the hot isostatic pressing is 1000 °C, the pressure is 5 MPa, and the compaction time is 60 hours. The foamed titanium foam is put into a hydrogen treatment furnace for vacuum annealing to remove hydrogen at a temperature of 800 °C for 5 hours to obtain a titanium foam product with certain mechanical properties.

[0032] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a foamed titanium product using titanium hydride powder, characterized in that: The following steps are involved: 1) After hydrogenation, the titanium sponge is crushed and sieved through 75-80 meshes, and the sieved titanium hydride powder is used as the raw material; 2) placing the raw material in a prefabricated mold, evacuating the air, filling it with argon gas at a certain pressure, and pressing it into shape to obtain a prefabricated blank; 3) The prefabricated blank is compacted in a low-pressure environment and foamed at high temperature, and a crude titanium foam product is obtained after the high-temperature foaming is completed; 4) The crude titanium foam product is placed in a hydrogen treatment furnace for dehydrogenation to obtain a titanium foam product.

2. The method for preparing a foamed titanium product using titanium hydride powder according to claim 1, characterized in that: The particle size of the sieved titanium hydride powder is 40 to 200 microns.

3. The method for preparing a foamed titanium product using titanium hydride powder according to claim 1, characterized in that: The prefabricated mold is a steel sleeve.

4. The method for preparing a foamed titanium product using titanium hydride powder according to claim 1, characterized in that: 2) The argon gas at a certain pressure in the step is 0.1 to 10 kPa.

5. The method for preparing a foamed titanium product using titanium hydride powder according to claim 1, characterized in that: 3) In the step, the low pressure environment is 1-5 MPa, the temperature of the high temperature foaming is 900-1000° C., and the compaction time is 20-60 hours.

6. The method for preparing a foamed titanium product using titanium hydride powder according to claim 1, characterized in that: 4) The dehydrogenation treatment in step 4 is vacuum annealing to remove hydrogen at a temperature of 600 to 800°C for 1 to 5 hours.