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CN-121978036-A - System and method for measuring surface tension and viscosity of high-temperature melt under pneumatic suspension condition

CN121978036ACN 121978036 ACN121978036 ACN 121978036ACN-121978036-A

Abstract

The invention discloses a system and a method for measuring the surface tension and viscosity of a high-temperature melt under the pneumatic suspension condition, and belongs to the technical field of material thermophysical property research. The system comprises an optical filtering unit, wherein the front end of the optical filtering unit is arranged outside an observation window of the pneumatic suspension device and used for carrying out spectrum selection and intensity attenuation on an incident light signal, the rear end of the optical filtering unit is connected with a photoelectric sensing unit, the photoelectric sensing unit is used for converting the light signal into an electric signal, the photoelectric sensing unit is connected with a data acquisition unit, the data acquisition unit is used for converting the electric signal into a digital signal, the data acquisition unit is connected with an information processing unit, and the information processing unit is used for processing the digital signal to realize measurement. The invention solves the problems of signal quality, acquisition efficiency, environmental adaptability, operation convenience and the like in the prior art, and can accurately acquire the surface tension and viscosity value of the high-temperature melt under the pneumatic suspension condition based on the integrated optical filtering and high-fidelity photoelectric detection technology.

Inventors

  • RUAN YING
  • SU XINYI
  • WEI BINGBO

Assignees

  • 西北工业大学

Dates

Publication Date
20260505
Application Date
20260211

Claims (10)

  1. 1. The measuring system is characterized by comprising an optical filtering unit, a photoelectric sensing unit, a data acquisition unit and an information processing unit, wherein the front end of the optical filtering unit is arranged on the outer side of an observation window of the pneumatic suspension device and is used for carrying out spectrum selection and intensity attenuation on an incident light signal according to the high-temperature spectral characteristics of a to-be-measured melt, the rear end of the optical filtering unit is connected with the photoelectric sensing unit, the photoelectric sensing unit is used for converting an accurately filtered light signal carrying high-temperature melt oscillation information into an electric signal, the photoelectric sensing unit is connected with the data acquisition unit, the data acquisition unit is used for converting the electric signal into a digital signal, the data acquisition unit is connected with the information processing unit, and the information processing unit is used for processing the acquired digital signal to realize measurement.
  2. 2. The system for measuring the surface tension and the viscosity of the high-temperature melt under the pneumatic suspension condition according to claim 1, wherein the optical filtering unit comprises a protection shell, a filtering component, a driving component and a heat dissipation component, a circular light passing hole is formed in the front end of the protection shell, the circular light passing hole is opposite to the outer side of an observation window of the pneumatic suspension device, a standard optical interface is arranged at the rear end of the protection shell corresponding to the circular light passing hole, threads are arranged at the standard optical interface, the photoelectric sensing unit is connected through the threads, and the filtering component, the driving component and the heat dissipation component are arranged in the protection shell, and the driving component is in driving connection with the filtering component.
  3. 3. The system for measuring the surface tension and the viscosity of the high-temperature melt under the pneumatic suspension condition according to claim 2, wherein the light filtering component comprises a light filter, a driving rotating shaft, a light filter rotating wheel and a rotating wheel base, the rotating wheel base is arranged at the bottom of one side, close to the circular light transmission hole, of the inside of the protective shell, the driving rotating shaft is arranged at the top of the rotating wheel base, the light filter rotating wheel is arranged on the driving rotating shaft, a plurality of light filters are arranged on the light filter rotating wheel, the light filters are correspondingly arranged with the circular light transmission hole, and the driving component is in driving connection with the driving rotating shaft and is used for driving the driving rotating shaft to rotate so as to drive the selected light filter to rotate between the circular light transmission hole and a standard optical interface, so that light filtering is realized.
  4. 4. The system for measuring the surface tension and the viscosity of the high-temperature melt under the pneumatic suspension condition according to claim 2, wherein the photoelectric sensing unit comprises a focusing lens barrel, a coaxial aiming assembly and a photoelectric detector, the standard optical interface is connected with the focusing lens barrel through threads, the focusing lens barrel is connected with the photoelectric detector, an interchangeable focusing lens is fixedly arranged at the front end of the inner part of the focusing lens barrel through a pressing ring, and the coaxial aiming assembly is arranged at the rear end of the inner part of the focusing lens barrel.
  5. 5. The system for measuring the surface tension and the viscosity of the high-temperature melt under the pneumatic suspension condition according to claim 4, wherein the coaxial aiming assembly comprises a beam splitting lens, an indicating laser and a fixing clamp, the beam splitting lens and the fixing clamp are coaxially arranged on the top of the rear end of the interior of the focusing lens barrel in sequence, and the indicating laser is arranged on the fixing clamp.
  6. 6. The system for measuring the surface tension and the viscosity of the high-temperature melt under the pneumatic suspension condition according to claim 4, wherein the photoelectric detector comprises a shielding shell, a photodiode, a signal conditioning circuit and a driving circuit, wherein a standard optical interface is arranged at the front end of the shielding shell, threads are arranged at the standard optical interface and are connected with the rear end of the focusing lens through the threads, the photodiode is arranged in the standard optical interface of the shielding shell, the signal conditioning circuit is arranged in the shielding shell, the driving circuit is arranged on the lower side of the inside of the shielding shell, the driving circuit is connected with the signal conditioning circuit, and the signal conditioning circuit is connected with the photodiode.
  7. 7. The system for measuring the surface tension and the viscosity of the high-temperature melt under the pneumatic suspension condition according to claim 4, wherein the data acquisition unit comprises an external high-speed data acquisition card and a data transmission line, and the external high-speed data acquisition card is connected with the signal output end of the photoelectric sensing unit and the data input end of the information processing unit through the data transmission line.
  8. 8. The system for measuring the surface tension and the viscosity of the high-temperature melt under the pneumatic suspension condition according to claim 7, wherein the information processing unit comprises a computer workstation and measurement and control calculation software deployed on the computer workstation, the measurement and control calculation software comprises a system control and acquisition module, a signal preprocessing module, a characteristic analysis module, a physical property calculation module and a data management module which are sequentially connected, the system control and acquisition module is connected with the optical filtering unit and used for changing the rotation position of an optical filter and acquiring related data through controlling a driving component, the signal preprocessing module is used for carrying out noise reduction processing on the acquired digital signal, the characteristic analysis module is used for executing fast Fourier transformation to extract the characteristic oscillation frequency of the melt and executing nonlinear fitting to obtain the oscillation attenuation time of the melt, the physical property calculation module is used for automatically calculating the thermal physical property parameters of the high-temperature melt according to a set physical property based on the surface tension and viscosity physical formula of the melt, and the data management module is used for realizing data storage and report result generation and export.
  9. 9. A method for measuring the surface tension and viscosity of a high-temperature melt under a pneumatic suspension condition, which is applied to the system for measuring the surface tension and viscosity of the high-temperature melt under the pneumatic suspension condition, and is characterized by comprising the following steps: Step 1, preparing a sample to be tested and establishing an experimental environment; step 2, configuring an optical path of a measurement system; Step3, setting data acquisition parameters; Step 4, controlling a filter runner in an optical filter unit through measurement and control calculation software according to the melt attribute and the radiation spectrum of a sample to be measured, switching the filter runner to a preset filter combination, and adjusting a photoelectric detector in a photoelectric sensing unit to enable the amplitude of a digital signal output by a measuring system under static state to be 5% -30% of the range of a data acquisition card; Step 5, starting suspension and melting of a solid sample to be tested; step 6, exciting the sample melt to generate second-order oscillation; step 7, acquiring a second-order oscillation signal of the melt based on a measuring system; step 8, acquiring a melt damping attenuation signal based on a measurement system; Step 9, repeating the steps 6-8 to obtain multi-temperature point data; and 10, carrying out data processing and thermophysical parameter calculation based on the acquired data.
  10. 10. The method for measuring the surface tension and the viscosity of a high-temperature melt under the pneumatic suspension condition according to claim 9, wherein the sample to be measured comprises metal, inorganic nonmetal and metal ceramic.

Description

System and method for measuring surface tension and viscosity of high-temperature melt under pneumatic suspension condition Technical Field The invention relates to the technical field of material thermophysical property research, in particular to a system and a method for measuring the surface tension and viscosity of a high-temperature melt under the pneumatic suspension condition. Background The surface tension and viscosity are important thermophysical parameters for representing the material properties, and have key significance for clarifying the evolution rule of a liquid structure, the solidification dynamics mechanism and the service performance under extreme conditions. The traditional contact surface tension and viscosity measurement methods such as a maximum bubble pressure method, a hanging drop method, a spin column method and the like are easy to induce heterogeneous nucleation, and can not obtain the physical parameters of liquid metal and ceramic melt in metastable states such as deep supercooling and the like. The container-free technology provides technical support for physical property measurement of the high-temperature melt, wherein the pneumatic suspension technology is mainly applied to container-free treatment of refractory metals, oxide ceramics and other high-melting-point materials due to the unique advantages of wide material universality, high suspension stability, strong process controllability and the like. Under the pneumatic suspension condition, the liquid drop oscillation method is used for exciting the melt to generate resonance, and the surface tension and viscosity of the high-temperature melt are calculated according to the resonance frequency and damping characteristics, so that the principle is well-developed. However, the prior art still faces challenges in achieving high accuracy, high reliability measurements, which are limited primarily to signal acquisition and processing links. The current mainstream image method mostly depends on a high-speed shooting technology, namely, the profile change in the forced oscillation process of a high-temperature melt is shot, the sequence of the radius evolution along with time is extracted after image processing, and then the physical parameters are obtained through spectrum analysis or attenuation fitting. The technology is intuitive, but has the defects that firstly, in the aspect of data acquisition, the data resolution is limited by the frame rate of a camera, the obtained data are discrete point sequences, the detail characteristics of high-frequency oscillation of a melt are difficult to continuously and completely capture, and particularly, the description capability of key signals in the early stage of oscillation attenuation is insufficient, so that information is lost. For obtaining kilohertz data, a CCD camera with extremely high frame rate is needed, so that the equipment acquisition cost is remarkably increased, and massive image data simultaneously provides extremely high requirements for subsequent image processing calculation, thereby exacerbating the time cost and technical difficulty of data processing. Secondly, in terms of signal quality, the self-radiation intensity of the high-temperature melt is high, the spectrum is continuous, the local overexposure and the edge blurring of a shot image are easy to cause, and the contour recognition precision is obviously reduced. Even if the backlight illumination is adopted for assistance, the interference of strong heat radiation and stray light in a near-melt area is still difficult to thoroughly eliminate, so that the signal-to-noise ratio of an image is low, and the reliability of subsequent analysis is affected. In addition, in the data processing link, the acquired image is often subjected to multi-step post-processing such as edge detection, ellipse fitting, noise filtering and the like under the limitation of a nozzle structure and a suspension position in the pneumatic suspension device, the flow is complex, the time consumption is long, accumulated errors can be introduced by multiple operations, and the experimental requirements of real-time analysis and quick feedback are difficult to meet. In order to overcome the defects of the image method in time resolution and processing efficiency, the oscillation signal extraction method based on photoelectric detection is widely applied to container-free technologies such as electromagnetic suspension and the like. The method converts optical signals of oscillation and attenuation of the surface of the melt into electric signals, and obtains resonance frequency and attenuation characteristics through fast Fourier transformation. However, in the practical application scene of the pneumatic suspension technology, the method has remarkable restriction on the effectiveness of signal extraction, namely, the high-temperature melt surface oscillation amplitude is small, the self heat radiation intensity is high, the flu