Rapid solidification process for ultra-fine grain industrial silicon based on gas atomization
The rapid solidification process for ultrafine-grained industrial silicon, which combines gas atomization and nanoscale grain inhibitors with thermomechanical treatment, solves the problems of coarse grains and limited cooling rates in traditional metallurgical methods, and realizes the preparation of high-performance industrial silicon with significant grain refinement and performance improvement effects.
Patent Information
- Application Number
- CN202511620042.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-06
- Publication Date
- 2026-01-09
AI Technical Summary
Industrial silicon prepared by traditional metallurgical methods has large grains, uneven structure, and many internal defects, making it difficult to meet the stringent requirements of high-end manufacturing for material performance. Furthermore, the preparation technology of ultrafine-grained industrial silicon has limited cooling rate, unsystematic grain control methods, and low level of intelligent control.
By employing gas atomization technology combined with nanoscale grain inhibitors and thermomechanical treatment, micron or submicron-sized droplets are formed through high-pressure inert gas atomization to achieve ultra-high-speed cooling. Combined with nanoscale dispersion strengthening and grain boundary engineering, grain size and distribution are controlled. Finally, process parameters are optimized through intelligent production control.
Significant refinement of industrial silicon grains has been achieved, with an average grain size ≤10μm, grain size distribution uniformity improved by an order of magnitude, performance significantly improved, tensile strength ≥150MPa, elongation ≥8%, and overall power consumption reduced.
Abstract
Description
Technical Field
[0001] This invention relates to the field of rapid solidification technology for ultrafine-grained industrial silicon, specifically to a rapid solidification process for ultrafine-grained industrial silicon based on gas atomization. Background Technology
[0002] Industrial silicon is a key basic material for strategic emerging industries such as new energy and electronic information. Its purity and microstructure directly affect the performance of the final product. Industrial silicon prepared by traditional metallurgical methods has problems such as coarse grains, uneven structure and many internal defects, making it difficult to meet the stringent requirements of high-end manufacturing fields for material performance.
[0003] Currently, there has been considerable research on ultra-high-speed cooling and grain refinement in existing technologies, and some technologies have been industrialized. However, in the preparation technology of ultra-fine industrial silicon, there are still problems such as limited cooling rate, unsystematic grain control methods, and low level of intelligent control. Summary of the Invention
[0004] (a) Technical problems to be solved
[0005] The technical problem to be solved by the present invention is to provide a rapid solidification process for ultrafine-grained industrial silicon based on gas atomization, which integrates rapid solidification, dispersion strengthening and grain boundary engineering to achieve significant refinement of industrial silicon grains and performance improvement.
[0006] (II) Technical Solution
[0007] To solve the above-mentioned technical problems, the technical solution provided by the present invention is: a rapid solidification process for ultrafine-grained industrial silicon based on gas atomization, comprising the following steps:
[0008] S1. Raw material preparation and smelting: Industrial silicon raw materials are placed in a smelting device and heated until completely melted to obtain pure silicon melt, which is then refined.
[0009] S2. Rapid Solidification via Gas Atomization: The refined silicon melt is conveyed to an atomization device through a guide pipe. An optimized high-pressure inert gas is used to atomize the silicon melt, forming micron- or submicron-sized droplets. The ultra-high-speed cooling effect of the high-pressure inert gas ensures that the average cooling rate of the silicon droplets consistently reaches and exceeds 10. 6 K / s promotes the nucleation and rapid solidification of silicon melt, resulting in fine-grained silicon-based alloy powder;
[0010] S3. Introduction of grain inhibitor and dispersion strengthening: During the melting process in step S1 or the atomization process in step S2, nano-scale grain inhibitors are precisely introduced to control their particle size, morphology, addition amount and distribution. The growth of grains after solidification is suppressed by utilizing the nano-scale dispersion particle strengthening theory.
[0011] S4. Thermomechanical treatment and grain boundary engineering: The silicon-based alloy powder obtained in step S2 is subjected to subsequent optimized thermomechanical treatment to regulate the grain boundary structure, grain boundary energy and grain orientation distribution, so as to achieve an average grain size of ≤10μm for industrial silicon products and a standard deviation of grain size distribution of ≤15%.
[0012] As an improvement, in step S2, the atomizing device adopts an optimized tightly coupled nozzle structure, and the high-pressure inert gas is high-purity argon or nitrogen, with the gas pressure controlled between 2.0 and 8.0 MPa.
[0013] As an improvement, in step S2, a high-speed camera observation system and a non-contact infrared temperature measurement system are integrated to monitor the cooling behavior of the atomization field and droplets in real time, collect experimental data and iteratively verify it with the established heat and mass transfer mathematical model, so as to optimize and stabilize the rapid solidification process window.
[0014] As an improvement, in step S3, the nanoscale grain inhibitor is one or more of TiN, Si3N4, and Al2O3, and its addition amount accounts for 0.1% to 2.0% of the silicon substrate mass, with an average particle size ≤100nm.
[0015] As an improvement, the nanoscale grain inhibitor is introduced simultaneously during atomization in the form of composite alloy powder via a pneumatic powder feeding system to achieve uniform mixing with the silicon melt.
[0016] As an improvement, in step S4, the thermomechanical treatment includes one or more of the following processes: hot isostatic pressing, hot extrusion, or sparkplasmasintering, with the treatment temperature controlled between 800 and 1200°C.
[0017] As an improvement, the ultrafine-grained industrial silicon product prepared by the aforementioned process has a tensile strength ≥150MPa and an elongation ≥8%.
[0018] As an improvement, the process is carried out on a pilot production line with an integrated DCS distributed control system, and the overall power consumption per ton of silicon is controlled at ≤9000kWh.
[0019] As an improvement, step S5, intelligent production control, is also included: based on the industrial Internet of Things architecture, high-precision sensors are installed to collect key parameters and equipment operating status data in real time during the production process; distributed storage and big data management technologies are used to process the data; machine learning algorithms are used to establish intelligent prediction models and develop dynamic optimization and control algorithms to control the overall fluctuation range of key process parameters within ≤5%.
[0020] (III) Beneficial Effects
[0021] The advantages of this invention compared to existing technologies are: by optimizing the combination of the atomizing nozzle and high-pressure inert gas (2.0–8.0 MPa), the average cooling rate of the silicon melt is ensured to consistently exceed 10. 6 K / s achieves extremely high supercooling and nucleation rate. Combined with the dispersion strengthening effect of nanoscale grain inhibitors (such as TiN, Si3N4, etc.), grain growth is effectively suppressed. Then, through subsequent thermomechanical treatment (such as hot isostatic pressing) for grain boundary engineering control, the average grain size of industrial silicon products is ≤10μm, and the grain size distribution is uniform with a standard deviation of ≤15%, which is at least an order of magnitude better than the grain refinement effect of traditional processes. Detailed Implementation
[0022] The invention will now be described in further detail with reference to specific embodiments, but this should not be construed as limiting the scope of the subject matter of the invention to the following embodiments.
[0023] Example 1
[0024] A rapid solidification process for ultrafine-grained industrial silicon based on gas atomization, characterized by comprising the following steps:
[0025] S1. Raw material preparation and smelting: Industrial silicon raw materials are placed in a smelting device and heated until completely melted to obtain pure silicon melt, which is then refined.
[0026] S2. Rapid Solidification via Gas Atomization: The refined silicon melt is conveyed to an atomization device through a guide pipe. An optimized high-pressure inert gas is used to atomize the silicon melt, forming micron- or submicron-sized droplets. The ultra-high-speed cooling effect of the high-pressure inert gas ensures that the average cooling rate of the silicon droplets consistently reaches and exceeds 10. 5 K / s promotes the nucleation and rapid solidification of silicon melt, resulting in fine-grained silicon-based alloy powder. The atomizing device adopts an optimized tightly coupled nozzle structure. The high-pressure inert gas is high-purity argon or nitrogen, and the gas pressure is controlled at 8.0 MPa. By integrating a high-speed camera observation system and a non-contact infrared temperature measurement system, the cooling behavior of the atomization field and droplets is monitored in real time. Experimental data is collected and iteratively verified with the established heat and mass transfer mathematical model to optimize and stabilize the rapid solidification process window.
[0027] S3. Introduction and dispersion strengthening of grain inhibitors: During the melting process in step S1 or the atomization process in step S2, nano-sized grain inhibitors are precisely introduced to control their particle size, morphology, addition amount and distribution. The growth of grains after solidification is suppressed by the nano-sized dispersion particle strengthening theory. The nano-sized grain inhibitors are TiN and Si3N4, and their addition amount accounts for 2.0% of the silicon matrix mass. The average particle size is ≤100nm. The nano-sized grain inhibitors are introduced simultaneously during the atomization process in the form of composite alloy powder through a pneumatic powder feeding system to achieve uniform mixing with the silicon melt.
[0028] S4. Thermomechanical treatment and grain boundary engineering: The silicon-based alloy powder obtained in step S2 is subjected to subsequent optimized thermomechanical treatment to regulate the grain boundary structure, grain boundary energy and grain orientation distribution, so as to achieve an average grain size of ≤10μm for industrial silicon products and a standard deviation of grain size distribution of ≤15%. The thermomechanical treatment includes one or more combined processes of hot isostatic pressing, hot extrusion or sparkplasmasintering, and the treatment temperature is controlled at 1200℃.
[0029] S5. Intelligent Production Control: Based on the industrial Internet of Things architecture, high-precision sensors are installed to collect key parameters and equipment operating status data in real time during the production process; distributed storage and big data management technologies are used to process the data; machine learning algorithms are used to establish intelligent prediction models and develop dynamic optimization and control algorithms to control the overall fluctuation range of key process parameters within ≤5%.
[0030] The ultrafine-grained industrial silicon product prepared by the aforementioned process has a tensile strength ≥150MPa and an elongation ≥8%. The process is carried out on a pilot production line with an integrated DCS distributed control system, and the overall power consumption per ton of silicon is controlled at ≤9000kWh.
[0031] Example 2
[0032] A rapid solidification process for ultrafine-grained industrial silicon based on gas atomization, characterized by comprising the following steps:
[0033] S1. Raw material preparation and smelting: Industrial silicon raw materials are placed in a smelting device and heated until completely melted to obtain pure silicon melt, which is then refined.
[0034] S2. Rapid Solidification via Gas Atomization: The refined silicon melt is conveyed to an atomization device through a guide pipe. An optimized high-pressure inert gas is used to atomize the silicon melt, forming micron- or submicron-sized droplets. The ultra-high-speed cooling effect of the high-pressure inert gas ensures that the average cooling rate of the silicon droplets consistently reaches and exceeds 10. 5K / s promotes the nucleation and rapid solidification of silicon melt, resulting in fine-grained silicon-based alloy powder. The atomizing device adopts an optimized tightly coupled nozzle structure. The high-pressure inert gas is high-purity argon or nitrogen, and the gas pressure is controlled at 2.0 MPa. By integrating a high-speed camera observation system and a non-contact infrared temperature measurement system, the cooling behavior of the atomization field and droplets is monitored in real time. Experimental data is collected and iteratively verified with the established heat and mass transfer mathematical model to optimize and stabilize the rapid solidification process window.
[0035] S3. Introduction and dispersion strengthening of grain inhibitors: During the melting process in step S1 or the atomization process in step S2, nano-sized grain inhibitors are precisely introduced to control their particle size, morphology, addition amount and distribution. The growth of grains after solidification is suppressed by the nano-sized dispersion particle strengthening theory. The nano-sized grain inhibitor is TiN, and its addition amount accounts for 0.1% of the mass of the silicon matrix. The average particle size is ≤100nm. The nano-sized grain inhibitor is introduced simultaneously during the atomization process in the form of composite alloy powder through a pneumatic powder feeding system to achieve uniform mixing with the silicon melt.
[0036] S4. Thermomechanical treatment and grain boundary engineering: The silicon-based alloy powder obtained in step S2 is subjected to subsequent optimized thermomechanical treatment to regulate the grain boundary structure, grain boundary energy and grain orientation distribution, so as to achieve an average grain size of ≤10μm for industrial silicon products and a standard deviation of grain size distribution of ≤15%. The thermomechanical treatment includes one or more combined processes of hot isostatic pressing, hot extrusion or sparkplasmasintering, and the treatment temperature is controlled at 800℃.
[0037] S5. Intelligent Production Control: Based on the industrial Internet of Things architecture, high-precision sensors are installed to collect key parameters and equipment operating status data in real time during the production process; distributed storage and big data management technologies are used to process the data; machine learning algorithms are used to establish intelligent prediction models and develop dynamic optimization and control algorithms to control the overall fluctuation range of key process parameters within ≤5%.
[0038] The ultrafine-grained industrial silicon product prepared by the aforementioned process has a tensile strength ≥150MPa and an elongation ≥8%. The process is carried out on a pilot production line with an integrated DCS distributed control system, and the overall power consumption per ton of silicon is controlled at ≤9000kWh.
[0039] Example 3
[0040] A rapid solidification process for ultrafine-grained industrial silicon based on gas atomization, characterized by comprising the following steps:
[0041] S1. Raw material preparation and smelting: Industrial silicon raw materials are placed in a smelting device and heated until completely melted to obtain pure silicon melt, which is then refined.
[0042] S2. Rapid Solidification via Gas Atomization: The refined silicon melt is conveyed to an atomization device through a guide pipe. An optimized high-pressure inert gas is used to atomize the silicon melt, forming micron- or submicron-sized droplets. The ultra-high-speed cooling effect of the high-pressure inert gas ensures that the average cooling rate of the silicon droplets consistently reaches and exceeds 10. 5 K / s promotes the nucleation and rapid solidification of silicon melt, resulting in fine-grained silicon-based alloy powder. The atomizing device adopts an optimized tightly coupled nozzle structure. The high-pressure inert gas is high-purity argon or nitrogen, and the gas pressure is controlled at 5MPa. By integrating a high-speed camera observation system and a non-contact infrared temperature measurement system, the cooling behavior of the atomization field and droplets is monitored in real time. Experimental data is collected and iteratively verified with the established heat and mass transfer mathematical model to optimize and stabilize the rapid solidification process window.
[0043] S3. Introduction and dispersion strengthening of grain inhibitor: During the melting process in step S1 or the atomization process in step S2, a nano-scale grain inhibitor is precisely introduced to control its particle size, morphology, addition amount and distribution. The growth of grains after solidification is suppressed by the nano-scale dispersion particle strengthening theory. The nano-scale grain inhibitor is Si3N, and its addition amount accounts for 1% of the mass of the silicon matrix. The average particle size is ≤100nm. The nano-scale grain inhibitor is introduced simultaneously during the atomization process in the form of composite alloy powder through a pneumatic powder feeding system to achieve uniform mixing with the silicon melt.
[0044] S4. Thermomechanical treatment and grain boundary engineering: The silicon-based alloy powder obtained in step S2 is subjected to subsequent optimized thermomechanical treatment to regulate the grain boundary structure, grain boundary energy and grain orientation distribution, so as to achieve an average grain size of ≤10μm for industrial silicon products and a standard deviation of grain size distribution of ≤15%. The thermomechanical treatment includes one or more combined processes of hot isostatic pressing, hot extrusion or sparkplasmasintering, and the treatment temperature is controlled at 1000℃.
[0045] S5. Intelligent Production Control: Based on the industrial Internet of Things architecture, high-precision sensors are installed to collect key parameters and equipment operating status data in real time during the production process; distributed storage and big data management technologies are used to process the data; machine learning algorithms are used to establish intelligent prediction models and develop dynamic optimization and control algorithms to control the overall fluctuation range of key process parameters within ≤5%.
[0046] The ultrafine-grained industrial silicon product prepared by the aforementioned process has a tensile strength ≥150MPa and an elongation ≥8%. The process is carried out on a pilot production line with an integrated DCS distributed control system, and the overall power consumption per ton of silicon is controlled at ≤9000kWh.
[0047] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents. In short, if those skilled in the art are inspired by these claims and design similar structural methods and embodiments without departing from the inventive spirit of the present invention, they should all fall within the protection scope of the present invention.
Claims
1. A rapid solidification process for ultrafine-grained industrial silicon based on gas atomization, characterized in that, Includes the following steps: S1. Raw material preparation and smelting: Industrial silicon raw materials are placed in a smelting device and heated until completely melted to obtain pure silicon melt, which is then refined. S2. Rapid Solidification via Gas Atomization: The refined silicon melt is conveyed to an atomization device through a guide pipe. An optimized high-pressure inert gas is used to atomize the silicon melt, forming micron- or submicron-sized droplets. The ultra-high-speed cooling effect of the high-pressure inert gas ensures that the average cooling rate of the silicon droplets consistently reaches and exceeds 10. 6 K / s promotes the nucleation and rapid solidification of silicon melt, resulting in fine-grained silicon-based alloy powder; S3. Introduction of grain inhibitor and dispersion strengthening: During the melting process in step S1 or the atomization process in step S2, nano-scale grain inhibitors are precisely introduced to control their particle size, morphology, addition amount and distribution. The growth of grains after solidification is suppressed by utilizing the nano-scale dispersion particle strengthening theory. S4. Thermomechanical treatment and grain boundary engineering: The silicon-based alloy powder obtained in step S2 is subjected to subsequent optimized thermomechanical treatment to regulate the grain boundary structure, grain boundary energy and grain orientation distribution, so as to achieve an average grain size of ≤10μm for industrial silicon products and a standard deviation of grain size distribution of ≤15%.
2. The rapid solidification process for ultrafine-grained industrial silicon based on gas atomization according to claim 1, characterized in that: In step S2, the atomizing device adopts an optimized tightly coupled nozzle structure, and the high-pressure inert gas is high-purity argon or nitrogen, with the gas pressure controlled between 2.0 and 8.0 MPa.
3. The rapid solidification process for ultrafine-grained industrial silicon based on gas atomization according to claim 1, characterized in that: In step S2, by integrating a high-speed camera observation system and a non-contact infrared temperature measurement system, the cooling behavior of the atomization field and droplets is monitored in real time. Experimental data is collected and iteratively verified with the established heat and mass transfer mathematical model to optimize and stabilize the rapid solidification process window.
4. The rapid solidification process for ultrafine-grained industrial silicon based on gas atomization according to claim 1, characterized in that: In step S3, the nanoscale grain inhibitor is one or more of TiN, Si3N4, and Al2O3, and its addition amount accounts for 0.1% to 2.0% of the silicon substrate mass, with an average particle size ≤100nm.
5. The rapid solidification process for ultrafine-grained industrial silicon based on gas atomization according to claim 1, characterized in that: The nanoscale grain inhibitor is introduced simultaneously during atomization via a pneumatic powder feeding system in the form of composite alloy powder, achieving uniform mixing with the silicon melt.
6. The rapid solidification process for ultrafine-grained industrial silicon based on gas atomization according to claim 1, characterized in that: In step S4, the thermomechanical treatment includes one or more of the following processes: hot isostatic pressing, hot extrusion, or spark plasmasintering, with the treatment temperature controlled between 800 and 1200°C.
7. The rapid solidification process for ultrafine-grained industrial silicon based on gas atomization according to claim 1, characterized in that: The ultrafine-grained industrial silicon product prepared by the aforementioned process has a tensile strength ≥150MPa and an elongation ≥8%.
8. The rapid solidification process for ultrafine-grained industrial silicon based on gas atomization according to claim 1, characterized in that: The process is carried out on a pilot production line with an integrated DCS distributed control system, and the overall power consumption per ton of silicon is controlled at ≤9000kWh.
9. The rapid solidification process for ultrafine-grained industrial silicon based on gas atomization according to claim 1, characterized in that, It also includes step S5, intelligent production control: based on the industrial Internet of Things architecture, high-precision sensors are installed to collect key parameters and equipment operating status data in real time during the production process; distributed storage and big data management technologies are used to process the data; machine learning algorithms are used to establish intelligent prediction models and develop dynamic optimization and control algorithms to control the overall fluctuation range of key process parameters within ≤5%.