A method for measuring the surface tension of a titanium alloy melt

Abstract

This invention discloses a method for measuring the surface tension of molten titanium alloy. The method includes the following steps: 1. Melting Ti and Fe metals to obtain a TiFe block; 2. Using an air suspension device, melting the TiFe block and then solidifying it into TiFe spheres; 3. Using an electrostatic suspension device, melting the TiFe spheres and conducting an oscillation experiment to obtain a simulated resonance frequency; 4. Under conditions of containerlessness, microgravity, high vacuum, and above the melting point temperature, conducting an oscillation experiment on the TiFe spheres in conjunction with the simulated resonance frequency to obtain an oscillation curve, obtaining the actual resonance frequency based on the oscillation curve, and calculating the TiFe surface tension. This surface tension measurement method achieves stable suspension and precise control of molten titanium alloy droplets through oscillation experiments in a containerless, microgravity, and high vacuum environment, thereby obtaining accurate surface tension values, suitable for testing the surface tension of molten titanium alloy.

Description

Technical Field

[0001] This invention belongs to the field of titanium alloy thermophysical property testing technology, and in particular relates to a method for measuring the surface tension of titanium alloy melt. Background Technology

[0002] Titanium alloys, with their superior specific strength, biocompatibility, and corrosion resistance, have established their cornerstone position in high-end equipment fields such as aviation, aerospace, and military. Facing the stringent requirements of future equipment for adaptability to extreme environments, the compositional design of novel titanium alloys has become a core challenge and focus of current materials design. Surface tension, as an important component of liquid interfacial phenomena, is of profound significance for understanding liquid behavior and optimizing the control of alloy microstructure and properties, providing a reliable database for new alloy design simulation and solidification experiments.

[0003] Furthermore, the thermophysical parameters of the melt are key technological bases for controlling the pore structure (porosity, pore size, pore wall thickness, etc.) of hollow titanium alloy spheres, directly guiding their controllable preparation process. Therefore, accurate measurement of the surface tension of titanium alloys is crucial to overcoming the limitations of existing alloy design and hollow sphere material preparation. However, current methods for testing the surface tension of melts mainly rely on the static drop method, which is affected by the instrument container walls and gravity, and the measurement accuracy needs further improvement. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for measuring the surface tension of molten titanium alloy. This method achieves stable suspension and precise control of molten titanium alloy droplets through oscillation experiments in a containerless, microgravity, and high-vacuum environment, thereby obtaining accurate surface tension values. This solves the problem of low measurement accuracy caused by the influence of containers and gravity in traditional surface tension measurements.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is: a method for measuring the surface tension of titanium alloy melt, characterized in that the method includes the following steps: Step 1: Melt Ti and Fe metals to obtain TiFe bulk material; Step 2: The TiFe block obtained in Step 1 is melted and then solidified using an air suspension device to obtain TiFe spheres; Step 3: Using an electrostatic levitation device, the TiFe spheres obtained in Step 2 are melted and subjected to a simulated oscillation experiment to obtain the simulated resonance frequency; Step 4: Under conditions of no container, microgravity, high vacuum, and above the melting point temperature, the TiFe spheres obtained in Step 2 are subjected to an oscillation experiment in conjunction with the simulated resonance frequency obtained in Step 3 to obtain the actual resonance frequency and calculate the TiFe surface tension.

[0006] This invention ensures suspension stability and avoids instability by preparing TiFe bulk material into spheres.

[0007] The above-mentioned method for measuring the surface tension of titanium alloy melt is characterized in that the TiFe block in step one is composed of the following components by mass percentage: Fe 31.90%~33.74%, with the balance being Ti and unavoidable impurities.

[0008] The above-mentioned method for measuring the surface tension of titanium alloy melt is characterized in that the diameter of the TiFe sphere in step two is 2.5 mm to 2.9 mm, and the mass of the TiFe sphere is 57 mg to 64 mg.

[0009] The above-mentioned method for measuring the surface tension of titanium alloy melt is characterized in that the method for obtaining the simulated resonance frequency in step three is as follows: the second-order oscillation generated by the electrostatic levitation device is used to excite the droplets formed by the melting of TiFe spheres to oscillate, the oscillation signal is collected, the oscillation curve is obtained, and the simulated optimal decay frequency is obtained by Fourier transform. Under the condition of the simulated optimal decay frequency, a decay experiment is carried out to obtain the decay curve, and the decay curve is Fourier transformed to obtain the simulated resonance frequency.

[0010] The above-mentioned method for measuring the surface tension of titanium alloy melt is characterized in that the oscillation experiment in step four is conducted using a containerless material experimental cabinet on a space station.

[0011] This invention utilizes a containerless material experiment cabinet from a space station to conduct oscillation experiments. This containerless material experiment cabinet can assist in oscillation experiments by providing a containerless, microgravity, and high-vacuum environment.

[0012] The above-mentioned method for measuring the surface tension of titanium alloy melt is characterized in that the method for obtaining the TiFe surface tension in step four specifically includes the following steps: Step 401: Place the TiFe spheres in a container without an acceleration not exceeding 10. -3 g. Vacuum degree not higher than 3×10 -3 Frequency sweep was performed under conditions of Pa and 1100℃~1300℃, and the frequency range of the sweep was set to include the entire range of simulated resonant frequencies to obtain the oscillation curve; Step 402: Obtain the actual optimal attenuation frequency by Fourier transforming the oscillation curve obtained in step 301. Conduct an attenuation experiment under the condition of the actual optimal attenuation frequency, and obtain the actual resonance frequency by Fourier transforming the attenuation curve obtained from the attenuation experiment. Then, calculate the TiFe surface tension based on the actual resonance frequency. The TiFe surface tension is calculated by the following formula: ; In the formula, σ is the surface tension of TiFe; m is the mass of the TiFe sphere, in mg; f n This is the actual resonant frequency, expressed in Hz.

[0013] This invention controls the temperature of the oscillation experiment to 1100℃~1300℃ to ensure complete melting of the TiFe eutectic alloy at its melting point of 1085℃; and sets the experiment to be containerless with an acceleration not exceeding 10. -3 The environmental characteristics of g are used to avoid interference from the environment on the oscillation curve, thereby obtaining the surface tension more accurately.

[0014] The above-mentioned method for measuring the surface tension of titanium alloy melt is characterized in that the step size of the frequency sweep in step 401 is no greater than 0.4 Hz / 3s.

[0015] Compared with the prior art, the present invention has the following advantages: 1. This invention utilizes a containerless, microgravity, and high-vacuum environment for oscillation experiments, which effectively controls the influence of containers and gravity on the accuracy of surface tension testing. It also avoids oxidation and contamination of titanium alloys and achieves stable suspension and precise control of molten titanium alloy droplets, thereby effectively improving the accuracy of surface tension parameter testing.

[0016] 2. This invention utilizes a TiFe eutectic alloy with a low melting point and good fluidity, ensuring the smooth conduct of the oscillation experiment within the space station. The success of this oscillation experiment within the space station provides the most direct and reliable verification for electrostatic levitation simulation experiments on Earth, and can provide a reference for the thermophysical property testing of other metal melts. It lays a solid foundation for deepening space science research and promoting the development of high-end titanium alloy materials. At the same time, it is conducive to establishing a database of thermophysical properties of titanium alloy materials, providing support for the design of new titanium alloys and the optimization of hollow sphere preparation processes.

[0017] 3. This invention uses the droplet oscillation method to test the surface tension of the melt. This method can accurately and effectively measure the evolution of the surface tension of the melt with temperature, reveal the physicochemical phenomena on the surface of titanium alloys, and is a powerful tool for exploring the surface properties of melts under extreme non-equilibrium conditions such as high temperature and deep supercooling.

[0018] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0019] Figure 1 This is a grayscale image of the TiFe 1# melt in step four of Example 1 of the present invention.

[0020] Figure 2 This is a decay curve of TiFe 1# melt in step four of Embodiment 1 of the present invention.

[0021] Figure 3 This is the actual resonance frequency diagram of TiFe 1# melt in step four of embodiment 1 of the present invention. Detailed Implementation

[0022] Five TiFe sphere samples were used in step four of Examples 1-5, designated as TiFe 1# to TiFe 5#, with masses ranging from 60.00 mg to 61.96 mg and diameters from 2.5 mm to 2.9 mm. All samples were sent to the Chinese Space Station aboard Tianzhou-8 and subjected to space oscillation experiments using a containerless materials experimental cabinet. The mass of the ground-matched TiFe spheres in each example was close to that of the TiFe sphere samples used in the space oscillation experiments. Furthermore, both the ground-matched TiFe spheres and TiFe 1# to TiFe 5# were composed of the following mass percentages: Fe 31.90% to 33.74%, with the remainder being Ti and unavoidable impurities.

[0023] Example 1 The surface tension measurement method in this embodiment includes the following steps: Step 1: Melt Ti and Fe metals to obtain TiFe bulk material; Step 2: The TiFe block obtained in Step 1 is remelted and solidified into TiFe spheres with a mass of 57mg~64mg using an air suspension device; Step 3: Using a ground-based electrostatic levitation device, a second-order oscillation generated by a high-voltage amplifier is used to excite the oscillation of a 60.20 mg TiFe sphere melted at 1300℃ into a droplet. The oscillation signal is collected, and the oscillation curve is obtained. The simulated optimal decay frequency is obtained through Fourier transform. The attenuation is performed 10 times under the simulated optimal decay frequency condition to obtain the decay curve. The Fourier transform of the decay curve yields a simulated resonant frequency of 145.27 Hz ± 3.99 Hz. The high-voltage amplifier itself can release a voltage of 0 keV to 50 keV. Step 4: Place 61.00 mg of TiFe 1# and 60.00 mg of TiFe 2# into the containerless materials experiment cabinet of the Chinese space station respectively to conduct a space oscillation experiment. Step 401, with acceleration not exceeding 10 -3 g. Vacuum degree not higher than 3×10 -3 Under the conditions of Pa and 1300℃, TiFe1# and TiFe2# were melted into melts, and then a frequency sweep was performed at 140Hz~150Hz with a step size of 0.4Hz / 3s and a single frequency sweep time of 75s to obtain the oscillation curves. Step 402: Based on the Fourier transform of the oscillation curves obtained in Step 401, the actual optimal decay frequencies of TiFe 1# and TiFe 2# are obtained as 147.80Hz and 149.88Hz, respectively. Then, a decay experiment at 1300℃ is conducted using the actual optimal decay frequencies to obtain the decay curves. The actual resonance frequency is obtained as 148.76Hz±1.01Hz using the Fourier transform of the decay curves. Subsequently, the surface tension of the TiFe eutectic alloy at 1300℃ is calculated as 1581.54mN / m±9.18mN / m based on the actual resonance frequency. The decay time in the decay experiment is 4s, and the decay is repeated 3 times.

[0024] A black and white photograph of the TiFe 1# melt in the spatial oscillation experiment in step four of this embodiment is shown below. Figure 1 As shown, the TiFe1# melt forms a sphere under conditions of no container, microgravity, and high vacuum; the decay curve of this TiFe1# melt is shown below. Figure 2 As shown, the decay curve follows a regular sine function. The smoothness of this function indicates that the oscillation experiment was successful. The actual resonant frequency after Fourier transform is as follows: Figure 3 As shown.

[0025] In step three of this embodiment, the simulated resonance frequency measured in the ground oscillation experiment was 145.27Hz±3.99Hz, and the actual resonance frequency measured in step four in the space oscillation experiment was 148.76Hz±1.01Hz. The two sets of resonance frequencies are very close, and the fluctuation range of the actual resonance frequency is smaller. This indicates that the resonance frequencies of TiFe 1# and TiFe 2# melts measured in the space station through the space oscillation experiment are more accurate, which in turn makes the surface tension more accurate.

[0026] Example 2 The difference between this embodiment and Embodiment 1 is as follows: In step three, the mass of the TiFe sphere is 61.00 mg, the temperature of the ground oscillation experiment is 1250℃, and the simulated resonance frequency is 144.27 Hz ± 5.37 Hz; In step four, TiFe 2# with a mass of 60.00 mg and TiFe 3# with a mass of 61.58 mg are used for the space oscillation experiment. The temperature during the space oscillation experiment is 1250℃, the frequency sweep range is 144 Hz to 154 Hz, and the attenuation experiment is performed 5 times. The actual optimal attenuation frequencies of TiFe 2# and TiFe 3# are 149.86 Hz and 149.32 Hz, respectively, and the actual resonance frequency is 146.98 Hz ± 4.84 Hz. The surface tension of the TiFe eutectic alloy at 1250℃ is 1608.04 mN / m ± 19.00 mN / m.

[0027] The simulated resonance frequency in this embodiment is very close to the actual resonance frequency, and the fluctuation range of the actual resonance frequency is smaller. This indicates that the resonance frequencies of TiFe 2# and TiFe 3# melts measured by space oscillation experiments in the space station are more accurate, which in turn makes the surface tension more accurate.

[0028] Example 3 The difference between this embodiment and Embodiment 1 is as follows: In step three, the mass of the TiFe sphere is 60.56 mg, the temperature of the ground oscillation experiment is 1200℃, and the simulated resonance frequency is 144.91 Hz ± 5.24 Hz; In step four, a space oscillation experiment is conducted using 60.00 mg of TiFe 2# and 60.48 mg of TiFe 4#. The temperature during the space oscillation experiment is 1200℃, the frequency sweep range is 144 Hz to 154 Hz, and the attenuation experiment is performed four times. The actual optimal attenuation frequencies of TiFe 2# and TiFe 4# are 149.82 Hz and 149.40 Hz, respectively, and the actual resonance frequency is 149.68 Hz ± 0.31 Hz. The surface tension of the TiFe eutectic alloy at 1200℃ is 1590.02 mN / m ± 3.62 mN / m.

[0029] The simulated resonance frequency in this embodiment is very close to the actual resonance frequency, and the fluctuation range of the actual resonance frequency is smaller. This indicates that the resonance frequencies of TiFe 2# and TiFe 4# melts measured by space oscillation experiments in the space station are more accurate, which in turn makes the surface tension more accurate.

[0030] Example 4 The difference between this embodiment and Embodiment 1 is as follows: In step three, the mass of the TiFe sphere is 62.00 mg, the temperature of the ground oscillation experiment is 1150℃, and the simulated resonance frequency is 143.01 Hz ± 4.40 Hz; In step four, TiFe 2# (mass 60.00 mg), TiFe 4# (mass 60.48 mg), and TiFe 5# (mass 61.96 mg) are used for the space oscillation experiment. The temperature during the space oscillation experiment is 1150℃, the frequency sweep range is 142 Hz to 152 Hz, and the attenuation experiment is performed 6 times. The actual optimal attenuation frequencies of TiFe 2# and TiFe 4# are 149.90 Hz, 149.40 Hz, and 149.40 Hz, respectively, and the actual resonance frequency is 150.30 Hz ± 0.45 Hz. The surface tension of the TiFe eutectic alloy at 1150℃ is 1607.53 mN / m ± 18.13 mN / m.

[0031] The simulated resonance frequency in this embodiment is very close to the actual resonance frequency, and the fluctuation range of the actual resonance frequency is smaller. This indicates that the resonance frequencies of TiFe 2# and TiFe 4# melts measured by space oscillation experiments in the space station are more accurate, which in turn makes the surface tension more accurate.

[0032] Example 5 The difference between this embodiment and Embodiment 1 is as follows: In step three, the mass of the TiFe sphere is 60.56 mg, the temperature of the ground oscillation experiment is 1100℃, and the simulated resonance frequency is 146.97 Hz ± 8.05 Hz; In step four, a space oscillation experiment is conducted using TiFe 4# with a mass of 60.48 mg. The temperature during the space oscillation experiment is 1100℃, the frequency sweep range is 145 Hz ~ 155 Hz, and the attenuation experiment is conducted three times. The actual optimal attenuation frequency of TiFe 4# is 149.40 Hz, the actual resonance frequency is 149.43 Hz ± 0.05 Hz, and the surface tension of the TiFe eutectic alloy at 1100℃ is 1590.89 mN / m ± 0.03 mN / m. The simulated resonance frequency in this embodiment is very close to the actual resonance frequency, and the fluctuation range of the actual resonance frequency is smaller. This indicates that the resonance frequency of TiFe 4# melt measured by space oscillation experiment in the space station is more accurate, which in turn makes the surface tension more accurate.

[0033] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the present invention. Any simple modifications, alterations, or equivalent structural transformations made to the above embodiments based on the technical essence of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A method for measuring the surface tension of a titanium alloy melt, characterized in that, The method includes the following steps: Step 1: Melt Ti and Fe metals to obtain TiFe bulk material; Step 2: The TiFe block obtained in Step 1 is melted and then solidified using an air suspension device to obtain TiFe spheres; Step 3: Using an electrostatic levitation device, the TiFe spheres obtained in Step 2 are melted and subjected to a simulated oscillation experiment to obtain the simulated resonance frequency; Step 4: Under conditions of no container, microgravity, high vacuum, and above the melting point temperature, the TiFe spheres obtained in Step 2 are subjected to an oscillation experiment in conjunction with the simulated resonance frequency obtained in Step 3 to obtain the actual resonance frequency and calculate the TiFe surface tension.

2. The method for measuring the surface tension of titanium alloy melt according to claim 1, characterized in that, The TiFe bulk material described in step one is composed of the following components by mass percentage: Fe 31.90%~33.74%, with the balance being Ti and unavoidable impurities.

3. The method for measuring the surface tension of titanium alloy melt according to claim 1, characterized in that, The diameter of the TiFe spheres in step two is 2.5 mm to 2.9 mm, and the mass of the TiFe spheres is 57 mg to 64 mg.

4. The method for measuring the surface tension of titanium alloy melt according to claim 1, characterized in that, The method for obtaining the simulated resonance frequency in step three is as follows: the second-order oscillation generated by the electrostatic levitation device excites the droplets formed by the melting of TiFe spheres to oscillate, the oscillation signal is collected, the oscillation curve is obtained, and the simulated optimal decay frequency is obtained by Fourier transform. Under the condition of the simulated optimal decay frequency, a decay experiment is carried out to obtain the decay curve, and the decay curve is Fourier transformed to obtain the simulated resonance frequency.

5. The method for measuring the surface tension of titanium alloy melt according to claim 1, characterized in that, The oscillation experiment described in step four was conducted using a containerless materials experimental cabinet on the space station.

6. The method for measuring the surface tension of a titanium alloy melt according to claim 1, characterized in that, The method for obtaining the TiFe surface tension described in step four specifically includes the following steps: Step 401: Place the TiFe spheres in a container without an acceleration not exceeding 10. -3 g. Vacuum degree not higher than 3×10 -3 Frequency sweep was performed under conditions of Pa and 1100℃~1300℃, and the frequency range of the sweep was set to include the entire range of simulated resonant frequencies to obtain the oscillation curve; Step 402: Obtain the actual optimal attenuation frequency by Fourier transforming the oscillation curve obtained in step 401. Conduct an attenuation experiment under the condition of the actual optimal attenuation frequency, and obtain the actual resonance frequency by Fourier transforming the attenuation curve obtained from the attenuation experiment. Then, calculate the TiFe surface tension based on the actual resonance frequency. The TiFe surface tension is calculated by the following formula: ； In the formula, σ is the surface tension of TiFe; m is the mass of the TiFe sphere in g; f n This is the actual resonant frequency, expressed in Hz.

7. The method for measuring the surface tension of a titanium alloy melt according to claim 6, characterized in that, The sweep step size is no greater than 0.4Hz / 3s.

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