Preparation method of micron-sized titanium fiber

Abstract

The invention discloses a micron-sized titanium fiber preparation method which comprises the following steps: carrying out heat treatment on a titanium plate, and carrying out heat preservation on the titanium plate after the heat treatment process to obtain a titanium plate soft structure; the titanium plate is pretreated, specifically, the titanium plate is cleaned, oil is removed, and an oxidation layer is removed; the titanium plate is subjected to ultrasonic-assisted rolling and pressing, and a thin strip is obtained; winding the thin strip to obtain a thin strip cylinder; and fixing the thin-strip cylinder on a rotating shaft R shaft of a three-shaft numerical control motion platform, carrying out jacking constraint on the other end of the thin-strip cylinder, and adjusting the rotating speed of the R shaft. Compared with the prior art, the method has the beneficial effects that a titanium plate with the thickness of 0.1-0.08 mm is rolled into a thin strip with the thickness of 0.015-0.025 mm through a 25K ultrasonic auxiliary roller, then the thin strip is wound into a cylinder with the diameter of 50-100 mm, then one end of the thin strip cylinder is clamped, the rotating speed is controlled to be 100-1000 rpm, finally, the thin strip cylinder is subjected to micron-order feeding cutting through a 40 KHz high-frequency piezoelectric cutter, the fiber equivalent diameter is 10-25 microns, and the thickness of the thin strip cylinder is 10-25 microns. The process is simple and low in cost.

Description

Technical Field

[0001] The invention belongs to the field of metal processing, and in particular relates to a method for preparing micron-grade titanium fiber. Background Art

[0002] Proton exchange membrane water electrolysis (PEM) is the mainstream method for pure water hydrogen production in the future. It has the characteristics of fast impact, good tolerance to voltage fluctuations, and high efficiency. It is suitable for energy storage of unstable power sources such as photovoltaics and wind power. The anode material mainly uses metal conductors with high oxidative corrosion potential, such as nickel and titanium. Nickel mesh and titanium mesh are more mature in commercial use, but the porosity of similar structures is low and the material specific surface area is small, which greatly limits the oxygen evolution efficiency. Titanium fiber sintered felt with finer fiber diameter is considered to be a better choice for PEM hydrogen production anode diffusion layer materials due to its higher specific surface area and lower interface resistance.

[0003] At present, the main technical routes for preparing titanium fibers are cluster drawing and mechanical vibration cutting. Since the room temperature structure of titanium materials is mainly face-centered cubic (hcp) α phase, there are few slip systems, resulting in poor plastic deformation ability. In order to improve plasticity, a higher heat treatment temperature is generally required (generally controlled at above 883°C), so the cluster drawing process is relatively complicated, the yield rate is low, and the cost is high. In order to solve the problem of insufficient room temperature plasticity, another low-cost technical route is high-speed mechanical vibration cutting. Titanium fiber is obtained by mechanical cutting of titanium parent material with specially designed carbide tools. This method has the advantages of high yield rate, no need for heat treatment, and short process flow. It is particularly suitable for the preparation of chopped fibers and porous titanium felt, and gradually becomes the main technical means for the industrialization of titanium fibers in the future. However, due to the low frequency of conventional mechanical vibration (generally efficient 800Hz), it is difficult to prepare thinner and more uniform titanium fibers below 20 microns. Summary of the invention

[0004] The purpose of the present invention is to provide a method for preparing micron-grade titanium fibers to solve the above-mentioned problems.

[0005] In order to achieve the above object, the present invention provides a method for preparing micron-grade titanium fiber, comprising:

[0006] S1, heat treating the titanium plate, and keeping the titanium plate warm after heating to obtain a soft structure of the titanium plate;

[0007] S2, pre-treating the titanium plate: cleaning, degreasing and removing the oxide layer of the titanium plate;

[0008] S3, performing ultrasonic assisted pressing on the titanium plate to obtain a thin strip;

[0009] S4, winding the thin strip to obtain a thin strip cylinder;

[0010] S5, fixing the thin strip cylinder on the rotating axis R axis of the 3-axis CNC motion platform, tightening and constraining the other end, and adjusting the R axis speed;

[0011] S6, placing a 40KHz high-frequency piezoelectric tool on the X and Y axes of the CNC motion platform, and setting the feed amount on the X and Y axes of the CNC motion platform;

[0012] S7, setting the chip breaking length of the numerical control motion platform, and obtaining titanium fiber wire after cutting.

[0013] In one or more embodiments of the present invention, the heat treatment in step S1 is as follows: after the temperature reaches 450-500°C, the titanium plate is placed in a furnace and heated to 900-950°C, kept at this temperature for 35-45 minutes, and then taken out of the furnace and air-cooled.

[0014] In one or more embodiments of the present invention, the cleaning in step S2 is to clean the carbide layer on the surface of the titanium plate that has undergone the heat treatment process.

[0015] In one or more embodiments of the present invention, the ultrasonic assisted pressing frequency is 20 KHz.

[0016] In one or more embodiments of the present invention, the thickness of the titanium plate is 0.1-0.08 mm, the thickness of the thin strip is 0.015-0.025 mm, and the width of the thin strip is 280 mm.

[0017] In one or more embodiments of the present invention, the winding in step S4 is to wind the thin strip around a winding rod to obtain a thin strip cylinder, and the outer diameter of the thin strip cylinder is 50 to 100 mm.

[0018] In one or more embodiments of the present invention, the R-axis speed in step S5 is 100-1000 rpm.

[0019] In one or more embodiments of the present invention, the feed rates of the X and Y axes of the numerical control motion platform in step S6 are respectively to control the Y axis feed rate to 0.001-0.005 mm / rev and to fix the X axis feed rate to 0.06 mm.

[0020] In one or more embodiments of the present invention, the chip length is 30-50 mm, and the chip length is equal to the length of the titanium fiber wire.

[0021] In one or more embodiments of the present invention, the equivalent diameter of the titanium fiber filament is 10-25 μm.

[0022] Compared with the prior art, the beneficial effect of the present invention is that it can prepare uniform titanium fibers below 20 microns, and the process is simple and low-cost, which can improve market competitiveness and play a role in improving production efficiency in the production of chopped fibers and porous titanium felt. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The present invention is a flow chart of the method for preparing micron-sized titanium fibers. DETAILED DESCRIPTION

[0024] The specific implementation modes of the present invention are described in detail below in conjunction with the accompanying drawings, but it should be understood that the protection scope of the present invention is not limited by the specific implementation modes.

[0025] refer to Figure 1 As shown, a method for preparing micron-sized titanium fiber is used to prepare uniform titanium fiber wires less than 20 mm by mechanical vibration, which is used to solve the problems of complex bundle drawing process, low yield and high cost. The method for preparing micron-sized titanium fiber includes the following steps:

[0026] S1. Heat treatment of titanium plate

[0027] Heat treatment is performed on the titanium plate. GB 4698 sponge titanium is used as the raw material titanium plate. A titanium plate with a thickness of 0.1 to 0.08 mm and a thickness tolerance of 0.02 to 0.03 mm is selected. The titanium plate is subjected to a heat treatment process. The titanium plate is slowly heated and then kept warm for a sufficient time, and then slowly cooled to eliminate the internal stress in the titanium plate and improve the plasticity of the titanium plate and the stability of the titanium plate structure. The titanium plate soft structure is obtained by slowly heating the temperature to 920 degrees, then maintaining the temperature for 40 minutes and slowly cooling.

[0028] S2. Titanium plate pretreatment

[0029] Pre-treating the titanium plate, removing impurities from the heat-treated titanium plate to avoid contamination in subsequent processes and ensure that the surface of the titanium plate is clean, flat and smooth. The pre-treatment step specifically includes: cleaning, degreasing and removing the oxide layer of the titanium plate;

[0030] The black carbonized layer formed on the surface of the titanium plate after the lubricating oil is applied and heat-treated is removed by using a cleaning solution containing hydrofluoric acid, nitric acid and distilled water. The black carbonized layer is cleaned to give the titanium plate surface a metallic luster.

[0031] By performing ultrasonic cleaning in deionized water, the high-frequency oscillation signal generated by the ultrasonic generator is converted into a high-frequency mechanical oscillation pair through the transducer, so that the residual oil on the titanium plate is dispersed in the cleaning liquid, and the degreasing of the titanium plate ensures the cleanliness of its surface, which is convenient for subsequent processes.

[0032] The oxide layer on the surface of the titanium plate is removed by pickling. The titanium plate is placed in a pickling tank for pickling. The pickling solution in the pickling tank is 70g / L to 110g / L sulfuric acid, the pickling temperature is 30 to 40°C, the power voltage is 2 to 3V, and the pickling time is 10 to 20S. The oxide layer on the surface of the titanium plate is removed by water washing in the pickling tank, the smoothness and surface quality of the titanium plate are restored, the mechanical properties of the titanium plate are improved, and the subsequent processing is convenient.

[0033] S3, Titanium plate pressing

[0034] The titanium plate is subjected to ultrasonic assisted pressing, and a 25K ultrasonic assisted rolling roller is used to press the titanium plate, so that the titanium plate with a thickness of 0.1 to 0.08 mm is pressed into a thin strip of 0.015 to 0.025 mm, a high-frequency vibration of 20 Khz is generated by the rolling roller, and the vibration is transmitted to the titanium plate blank, and the titanium plate is pressed into a thin strip with a width of 280 mm, and residual stress and hardened layer are compressed during the pressing of the titanium plate by ultrasonic assisted pressing, and the surface finish of the thin strip is improved at the same time;

[0035] S4, Strip Winding

[0036] The thin strip is wound on a reel to obtain a thin strip cylinder, and the titanium thin strip is wound according to predetermined parameters by a winding device, and the tension, winding speed and position are controlled to wind the titanium thin strip into a cylinder with a diameter of 50 to 100 mm;

[0037] S5. Install the thin strip cylinder on the CNC platform

[0038] The thin strip cylinder is fixed on the rotating axis R axis of the three-axis CNC motion platform, the thin strip cylinder is clamped by a clamp, and the other end of the thin strip cylinder is tightened and constrained, and then the R axis speed is adjusted to set the R axis speed to 100-1000 rpm;

[0039] S6. Set the tool feed rate

[0040] A 40KHz high-frequency piezoelectric tool is installed on a three-axis CNC motion platform and placed on the X and Y axes of the CNC motion platform. The high-frequency piezoelectric tool uses the piezoelectric effect to generate high-frequency vibrations, and the thin-strip cylinder is continuously and stably cut through the mechanical deformation of the piezoelectric ceramic material under the action of the electric field and the extremely high cutting speed and precision generated during the processing. The feed amounts on the X and Y axes of the CNC motion platform are set to control the Y-axis feed amount to 0.001-0.005mm / rev, and the X-axis feed amount is fixed to 0.06mm. The equivalent diameter and cutting speed of the titanium fiber finally cut are controlled by setting the feed amounts on the X and Y axes;

[0041] S7, set the CNC platform cut length and perform cutting

[0042] The chip breaking length of the CNC motion platform is set, and the chip breaking length can be set to 30-50 mm. The chip breaking length is equal to the length of the prepared titanium fiber, that is, when the chip breaking length is set to 30-50 mm, the prepared length of the titanium fiber is also 30-50 mm. The titanium fiber filament is produced by cutting the thin strip cylinder with a high-frequency piezoelectric tool. The cross-sectional shape of the titanium fiber can be controlled by controlling the cutting depth of the high-frequency piezoelectric tool, that is, controlling the fixed X-axis feed amount on the three-axis CNC motion platform to 0.06 mm. The equivalent diameter of the titanium fiber can be controlled by controlling the Y-axis feed amount on the three-axis CNC motion platform to 0.001-0.005 mm / rev, and finally a titanium fiber filament with a quadrilateral cross-section close to a rectangle and an equivalent diameter of 10-25 microns is obtained.

[0043] Example 1

[0044] Step 1: First, heat treat the 0.1 mm thick titanium plate at a temperature of 920 degrees for 40 minutes to remove stress and obtain a soft structure;

[0045] Step 2: Clean and degrease the heat-treated titanium plate (degreasing temperature 30-55° C.) to remove grease and oxide layer;

[0046] Step 3: The 0.1 mm titanium plate is then subjected to ultrasonic assisted pressing at an ultrasonic frequency of 20 KHz to obtain a thin strip with a thickness of 0.015 mm and a width of 280 mm;

[0047] Step 4, winding the thin strip to obtain a thin strip cylinder with an outer diameter of 58 mm;

[0048] Step 5: Place one end of the thin ribbon cylinder on the rotating axis R axis of the 3-axis micron-level CNC motion platform, and tighten the other end to constrain the runout, and control the R axis speed to 120 rpm;

[0049] Step 6: Place the 40KHz high-frequency piezoelectric tool on the X and Y motion platforms, control the Y-axis feed rate to 0.001mm / rev, and fix the X-axis feed rate to 0.06mm;

[0050] Step 7: Set the chip breaking length to 40 mm, and titanium fibers with a length of 40 mm and an equivalent diameter of about 14 microns can be uniformly prepared.

[0051] Example 2

[0052] Step 1: First, heat treat the 0.09 mm thick titanium plate at a temperature of 920 degrees for a holding time of 40 minutes to remove stress and obtain a soft structure;

[0053] Step 2: Clean and degrease the heat-treated titanium plate (degreasing temperature 30-55° C.) to remove grease and oxide layer;

[0054] Step 3: The 0.09 mm titanium plate is then subjected to ultrasonic assisted pressing at an ultrasonic frequency of 20 KHz to obtain a thin strip with a thickness of 0.02 mm and a width of 280 mm;

[0055] Step 4, winding the thin strip to obtain a thin strip cylinder with an outer diameter of 72 mm;

[0056] Step 5: Place one end of the thin ribbon cylinder on the rotating axis R axis of the 3-axis micron-level CNC motion platform, and tighten the other end to constrain the runout, and control the R axis speed to 230 rpm;

[0057] Step 6: Place the 40KHz high-frequency piezoelectric tool on the X and Y motion platforms, control the Y-axis feed rate to 0.003mm / rev, and fix the X-axis feed rate to 0.06mm;

[0058] Step 7: Set the chip breaking length to 80 mm, and titanium fibers with a length of 80 mm and an equivalent diameter of about 19 microns can be uniformly prepared.

[0059] Example 3

[0060] Step 1: First, heat treat the 0.095 mm thick titanium plate at a temperature of 920 degrees for a holding time of 40 minutes to remove stress and obtain a soft structure;

[0061] Step 2: Clean and degrease the heat-treated titanium plate (degreasing temperature 30-55° C.) to remove grease and oxide layer;

[0062] Step 3: The 0.095 mm titanium plate is then subjected to ultrasonic assisted pressing at an ultrasonic frequency of 20 KHz to obtain a thin strip with a thickness of 0.022 mm and a width of 280 mm;

[0063] Step 4, winding the thin strip to obtain a thin strip cylinder with an outer diameter of 80 mm;

[0064] Step 5: Place one end of the thin ribbon cylinder on the rotating axis R axis of the 3-axis micron-level CNC motion platform, and tighten the other end to constrain the runout, and control the R axis speed to 350 rpm;

[0065] Step 6: Place the 40KHz high-frequency piezoelectric tool on the X and Y motion platforms, control the Y-axis feed rate to 0.004mm / rev, and fix the X-axis feed rate to 0.06mm;

[0066] Step 7: Setting the chip breaking length to 100 mm, titanium fibers with a length of 100 mm and an equivalent diameter of about 21 microns can be uniformly prepared.

[0067] Example 4

[0068] Step 1: First, heat treat the 0.08 mm thick titanium plate at a temperature of 920 degrees for 40 minutes to remove stress and obtain a soft structure;

[0069] Step 2: Clean and degrease the heat-treated titanium plate (degreasing temperature 30-55° C.) to remove grease and oxide layer;

[0070] Step 3: The 0.08 mm titanium plate is then subjected to ultrasonic assisted pressing at an ultrasonic frequency of 20 KHz to obtain a thin strip with a thickness of 0.025 mm and a width of 280 mm;

[0071] Step 4, winding the thin strip to obtain a thin strip cylinder with an outer diameter of 100 mm;

[0072] Step 5: Place one end of the thin ribbon cylinder on the rotating axis R axis of the 3-axis micron-level CNC motion platform, and tighten the other end to constrain the runout, and control the R axis speed to 500 rpm;

[0073] Step 6: Place the 40KHz high-frequency piezoelectric tool on the X and Y motion platforms, control the Y-axis feed rate to 0.005mm / rev, and fix the X-axis feed rate to 0.06mm;

[0074] Step 7: Set the chip breaking length to 120 mm, and titanium fibers with a length of 120 mm and an equivalent diameter of about 25 microns can be uniformly prepared.

[0075] During specific use, the titanium plate is first heat treated to remove stress, and then cleaned, degreased and pickled. The titanium plate is pressed using an ultrasonic assisted roller, and the 0.1-0.08 mm titanium plate is pressed into a 0.015-0.025 mm thin strip. The titanium thin strip is wound into a cylinder with a diameter of 50-100 mm through a winding device, and one end of the cylinder is clamped on a three-axis CNC platform, and the other end is tightened. Subsequently, the R-axis speed is set to 100-1000 rpm, a high-frequency piezoelectric tool is installed on the three-axis CNC platform, and a 40KHz high-frequency piezoelectric tool is used to perform micron-level feed cutting on the thin strip cylinder. The tool feed amount is set to 0.001-0.005 mm / rev, the feed amount of the X-axis and Y-axis is controlled, and the chip breaking length is set, so as to prepare titanium fibers with an approximately rectangular cross-section, and the fiber equivalent diameter is 10-25 micron titanium fiber filaments.

[0076] Compared with the prior art, the beneficial effect of the present invention is that a 25K ultrasonic assisted roller is used to press a 0.1-0.08mm titanium plate into a 0.015-0.025mm thin strip, and then the thin strip is wound into a cylinder with a diameter of 50-100mm, and then one end of the thin strip cylinder is clamped, the rotation speed is controlled to be 100-1000rpm, and finally a 40KHz high-frequency piezoelectric tool is used to perform micron-level feed cutting on the thin strip cylinder, with a feed amount of 0.001-0.005mm / rev, to prepare titanium fibers with a cross-section approximately rectangular and an equivalent fiber diameter of 10-25 microns. The preparation method can prepare uniform titanium fibers below 20 microns, and the process is simple and the cost is low, which can improve market competitiveness and play a role in improving production efficiency in the preparation of chopped fibers and porous titanium felt.

[0077] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0078] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A method for preparing micron-sized titanium fiber, characterized in that: include: S1, heat treating the titanium plate, and keeping the titanium plate warm after heating to obtain a soft structure of the titanium plate; S2, pre-treating the titanium plate: cleaning, degreasing and removing the oxide layer of the titanium plate; S3, performing ultrasonic assisted pressing on the titanium plate to obtain a thin strip; S4, winding the thin strip to obtain a thin strip cylinder; S5, fixing the thin strip cylinder on the rotating axis R axis of the 3-axis CNC motion platform, tightening and constraining the other end, and adjusting the R axis speed; S6, placing a 40KHz high-frequency piezoelectric tool on the X and Y axes of the CNC motion platform, and setting the feed amount on the X and Y axes of the CNC motion platform; S7, setting the chip breaking length of the numerical control motion platform, and obtaining titanium fiber wire after cutting.

2. The method for preparing micron-sized titanium fiber according to claim 1, characterized in that: The heat treatment in step S1 is as follows: after the temperature reaches 450-500° C., the titanium plate is placed in a furnace and heated to 900-950° C., kept at this temperature for 35-45 minutes, and then taken out of the furnace and air-cooled.

3. The method for preparing micron-sized titanium fiber according to claim 1, characterized in that: The cleaning in step S2 is to clean the carbide layer on the surface of the titanium plate that has undergone the heat treatment process.

4. The method for preparing micron-sized titanium fiber according to claim 1, characterized in that: The ultrasonic assisted pressing frequency is 20KHz.

5. The method for preparing micron-sized titanium fiber according to claim 4, characterized in that: The thickness of the titanium plate is 0.1-0.08 mm, the thickness of the thin strip is 0.015-0.025 mm, and the width of the thin strip is 280 mm.

6. The method for preparing micron-sized titanium fiber according to claim 1, characterized in that: The winding in the step S4 is to wrap the thin strip around a winding rod to obtain a thin strip cylinder, and the outer diameter of the thin strip cylinder is 50 to 100 mm.

7. The method for preparing micron-sized titanium fiber according to claim 1, characterized in that: The R-axis speed in step S5 is 100-1000 rpm.

8. The method for preparing micron-sized titanium fiber according to claim 1, characterized in that: The feed rates of the X and Y axes of the numerical control motion platform in step S6 are respectively to control the Y axis feed rate to 0.001-0.005 mm / rev and to fix the X axis feed rate to 0.06 mm.

9. The method for preparing micron-sized titanium fiber according to claim 1, characterized in that: The chip length is 30-50 mm, and the chip length is equal to the length of the titanium fiber wire.

10. The method for preparing micron-sized titanium fiber according to claim 1, characterized in that: The equivalent diameter of the titanium fiber wire is 10 to 25 μm.

Images