Reactive infiltration process numerical simulation method based on COMSOL multi-physics field coupling

Abstract

The invention provides a reactive infiltration process numerical simulation method based on COMSOL multi-physics field coupling, which comprises the following steps: constructing a simplified liquid silicon infiltration model, and simulating a pore structure of a porous body by adopting a two-dimensional single capillary equivalent model; based on the liquid silicon infiltration model, coupling a laminar flow-level set two-phase flow field, a chemical reaction field, a dilute substance transfer field and a fluid heat transfer field to form a multi-physical field numerical model; and a liquid silicon permeation height curve, concentration distribution and pore structure evolution data are obtained through transient solution. According to the method, the time cost required by calculation is saved by simplifying the model, meanwhile, the accuracy of the model can be ensured, and the pore structure change in the reaction infiltration process is predicted according to the reaction layer change rule obtained through simulation; the problem that in the prior art, pore closing critical conditions and a reaction-permeation dynamic coupling mechanism are lack of systematic revelation is effectively solved, theoretical support is provided for directional regulation and control of prefabricated body pore parameters and optimization of process parameters, and the method has remarkable innovativeness and practicability.

Description

Technical Field

[0001] This invention relates to the field of ceramic matrix composite material preparation technology, and more particularly to a numerical simulation method for reaction melting and infiltration process based on COMSOL multiphysics coupling. Background Technology

[0002] Reactive infiltration method ( ) is a method for preparing silicon carbide ceramic matrix composites ( / The process involves liquid silicon in porous carbon / carbon ( / Capillary infiltration in the preform allows for in-situ reaction with the carbon matrix to generate silicon carbide. The ceramic phase forms a dense structure, significantly improving the material's mechanical properties and thermal stability. Due to its excellent high-temperature resistance, thermal shock resistance, and lightweight characteristics, this material has become a core material in the thermal protection systems of high-speed aircraft.

[0003] Currently, reactive infiltration method ( Due to its short cycle, low cost, and lack of need for external field assistance, it is considered... / The most promising fabrication process for engineering applications. In this process, liquid silicon is in a porous... / The infiltration and reaction processes within the preform are crucial steps. However, existing processes still face three major technical bottlenecks: 1) limited liquid silicon penetration depth leads to internal pore defects; 2) fiber / matrix interface reactions cause fiber etching damage; and 3) the presence of residual silicon phase reduces the material's high-temperature performance. Research indicates that these problems are directly related to the dynamic evolution of the pore structure during the infiltration process. Under the combined action of infiltration and the ceramic phase generated by the reaction, the pore sidewalls of liquid silicon are gradually covered, leading to a shrinkage of the effective pore size. When the pore size drops to a critical size, the infiltration front stagnates, causing incomplete or supersaturated infiltration, which exacerbates fiber damage and silicon phase residue.

[0004] In existing technologies, researchers have studied the effects of surface reaction-induced ceramic phase growth and pore closure on melt flow using parametric models. Simulations have revealed that surface growth is primarily controlled by the reaction rate, but the chemical reaction mechanism has not been analyzed in depth; instead, the kinetic effects have been simulated using parametric models. Other studies have shown that... Melt / Interface A two-stage kinetic model of growth: initial heterogeneous nucleation and growth are controlled by carbon dissolution / reprecipitation, while later growth is controlled by carbon through continuous... The diffusion layer is dominant; however, this model, based on static diffusion dominance in solid-liquid reaction systems, does not consider... The melt infiltration process has been studied in several studies. Some studies, based on the level set method, the Navier-Stokes equations, and Young's equations, have simulated and analyzed the capillary flow process of molten silicon within porous silicon carbide preforms. These studies reveal that the pore structure significantly influences the infiltration path and defect distribution. However, these studies assume a stable pore structure within the preform and fail to reveal the potential impact of chemical reactions on the infiltration path, interfacial wettability, and the final microstructure of the preform. Other studies have used mesoscopic (Brinkman equations) to macroscopic (Richard equations) cross-scale flow field coupling to simulate the reactive melt infiltration process by incorporating governing equations for the flow, thermal, and chemical fields at corresponding physical field nodes. However, existing models primarily focus on the macroscopic effects of reaction products, only introducing governing equations to achieve mesoscopic and macroscopic flow field characteristics during reactive melt infiltration. Furthermore, some studies only discuss the infiltration or reaction process in isolation, failing to elucidate the evolution characteristics of the pore structure and the growth patterns of the reaction layer during melt infiltration. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a numerical simulation method for reactive melting and infiltration processes based on COMSOL multiphysics coupling. This invention can not only simulate… Layer growth and / The evolution of pore structure in porous bodies during the liquid silicon melting process can also demonstrate the rate-controlling steps and reaction mechanism of the reaction between liquid silicon and carbon matrix, thus overcoming the shortcomings of the existing technologies.

[0006] The technical means employed in this invention are as follows: A numerical simulation method for reactive melting and infiltration processes based on COMSOL multiphysics coupling includes: S1. Construct a simplified liquid silicon infiltration model and simulate it using a two-dimensional single capillary equivalent model. / The porous structure of porous materials; S2. Based on the liquid silicon melting and infiltration model, the laminar-horizontal two-phase flow field, chemical reaction field, rare matter transfer field and fluid heat transfer field are coupled to form a multiphysics numerical model. S3. Obtain the liquid silicon penetration height curve through transient solution. Concentration distribution and pore structure evolution data.

[0007] Further, in step S1, according to / The complex structure of multi-level pores between / within fiber bundles in porous bodies simplifies the local cannula pores into a two-dimensional axisymmetric single capillary equivalent model, specifically including: S11. A two-dimensional single capillary model is used to construct the geometric model, which consists of a liquid silicon molten pool and a porous flow channel. The width of the liquid silicon molten pool is 80 and the height is 20, and the width of the porous flow channel is 40 and the height is 100. S12. Set material properties, load the pore channel material as the first fluid - air, and load the liquid silicon molten pool material as the second fluid - liquid silicon.

[0008] Further, step S2 specifically includes: S21. Solve for the laminar-horizontal two-phase flow field; S22, Coupled chemical reaction field and rare matter transport field; S23. Introduce a fluid heat transfer field and correct the temperature field through a reaction heat source; S24. Couple two-phase flow horizontal collection, reactive flow of dilute substance, and non-isothermal flow in a multiphysics field, and set the wetting angle of the wetting wall as... .

[0009] Further, step S21 specifically includes: S211. Add a laminar flow field, which includes gravity. Set the inlet and outlet pressures to 0 and use the Navier-Stokes equations for incompressible fluids. The calculation formula is as follows:

[0010] in, Indicates the density of liquid silicon. Indicates the kinetic viscosity of liquid silicon. Represents the velocity field. g Represents the gravitational acceleration field. For pressure field, The tension at the liquid silicon interface, It is the identity matrix. t Let T represent time, and T denote transpose. S212. In the horizontal set function, the molten silicon pool is set as the second fluid and the pore channel as the first fluid. The phase interface is dynamically tracked through the horizontal set function, and its calculation formula is as follows:

[0011] in, For level set functions, when When, it indicates that it is in the first phase, when "Time" indicates that it is in the second phase; These are the renormalization control parameters; These are parameters for controlling the phase interface thickness.

[0012] Further, step S22 specifically includes: S221. Add a reaction to a chemical field, and set up a reaction domain. and Reaction generation Its chemical reaction formula is:

[0013] S222. Calculate the reaction rate based on the Arrhenius equation. The calculation formula is as follows:

[0014] in, and The concentrations of carbon and silicon are respectively. and Here, represents the reaction order and the reaction rate constant. With temperature The relationship is:

[0015] in, Pre-exponential factor, For activation energy, Let be the ideal gas constant. T For temperature; S223. Setting transport properties in a rare matter transport field, including: The diffusion coefficient is set to 1.51 × 10⁻⁶. -14 ; Add a reaction and set the reaction domain. , , The initial concentration is 0, and the inlet is set. The inflow concentration is set on the carbon matrix surface. The concentration was determined, and surface reaction boundary conditions were added, setting the reaction rate to the rate calculated in step S222 chemical field.

[0016] Further, step S3 specifically includes: S31. Using a mapped mesh, a mesh is generated for the entire multiphysics numerical model. S32. Simulate and solve the model using transient equations to obtain... - Reaction generation Concentration distribution Curves showing the changes in reaction layer thickness distribution and single capillary pore size as the reaction layer shrinks.

[0017] Furthermore, the aforementioned Reaction layer thickness distribution used for prediction / The critical conditions for pore closure in porous bodies guide the optimization of pore parameters in preforms and the control of melting infiltration process parameters.

[0018] Compared with the prior art, the present invention has the following advantages: 1. This invention provides a numerical simulation method for reactive melting and infiltration processes based on COMSOL multiphysics coupling. This method simulates the reaction melting and infiltration process of liquid silicon in COMSOL finite element software. / The reactive melting and infiltration process in porous materials was simulated, and the results obtained are consistent with actual phenomena. Layer growth pattern. This method significantly reduces experimental time and cost, and provides guidance for the design of pore structure and control of melt infiltration process parameters in carbon-based preforms.

[0019] 2. This invention provides a numerical simulation method for reactive melting and infiltration processes based on COMSOL multiphysics coupling. This method can clearly investigate the infiltration process of liquid silicon and the reaction mechanism between liquid silicon and the carbon matrix during reactive melting and infiltration. In the initial stage of the reaction, the interfacial reaction mechanism dominates. melt and Direct contact with the substrate. Atoms and Atoms react at the contact interface, along Directional growth of substrate surface Layers; and in the later stages, - The reaction rate then shifts to the atomic flow rate. Layer diffusion transport is dominant.

[0020] 3. This invention provides a numerical simulation method for reaction melting and infiltration processes based on COMSOL multiphysics coupling. This method overcomes the limitations of existing research that only focuses on macroscopic results and studies infiltration or reaction in isolation. It elucidates the growth law of the reaction layer during melt infiltration. Layer growth pattern prediction / The pore structure evolution of porous materials during liquid silica infiltration was simulated, and the simulation results showed good agreement with the experimental data from relevant literature. This method can guide the setting of infiltration time for porous materials with different pore sizes in actual experiments, avoiding premature pore closure and subsequent liquid silica infiltration. This also avoids the problem of insufficient penetration depth; and also prevents liquid from flowing out due to the pore closure time being longer than the melting and infiltration time. Excessive penetration damages fibers and leaves unreacted residues inside porous structures. The problem.

[0021] Based on the above reasons, this invention can be widely applied in fields such as the preparation of ceramic matrix composites. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a flowchart of the method of the present invention.

[0024] Figure 2 The two-dimensional geometric model provided in the embodiments of the present invention.

[0025] Figure 3 Provided for embodiments of the present invention - Reaction generation Concentration distribution.

[0026] Figure 4 Provided for embodiments of the present invention Layer thickness distribution.

[0027] Figure 5 The curve showing the change in single capillary pore size with the shrinkage of the reaction layer is provided for an embodiment of the present invention.

[0028] Figure 6 Provided for embodiments of the present invention Comparison of simulation and experimental results for layer thickness.

[0029] In the figure: 1. Molten silicon pool; 2. Porous flow channel and reaction zone; 3. First inlet; 4. Second inlet; 5. Outlet; 6. First carbon matrix; 7. Second carbon matrix; 8. First wetting wall; 9. Second wetting wall; 10. No flow boundary. Detailed Implementation

[0030] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0031] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0032] like Figure 1 As shown, this invention provides a numerical simulation method for reactive melting and infiltration processes based on COMSOL multiphysics coupling, comprising: S1. Construct a simplified liquid silicon infiltration model and simulate it using a two-dimensional single capillary equivalent model. / Pore ​​structure of porous bodies S2. Based on the liquid silicon melting and infiltration model, the laminar-horizontal two-phase flow field, chemical reaction field, rare matter transfer field and fluid heat transfer field are coupled to form a multiphysics numerical model. S3. Obtain the liquid silicon penetration height curve through transient solution. Concentration distribution and pore structure evolution data.

[0033] In a specific implementation, as a preferred embodiment of the present invention, in step S1, according to / The complex structure of multi-level pores between / within fiber bundles in porous bodies simplifies the local cannula pores into a two-dimensional axisymmetric single capillary equivalent model, specifically including: S11. Construct a geometric model using a two-dimensional single capillary model, such as... Figure 2 As shown, it consists of a liquid silicon molten pool 1 and a porous flow channel 2. The width of the liquid silicon molten pool 1 is 80 and the height is 20, and the width of the porous flow channel 2 is 40 and the height is 100. S12. Set material properties, load the material of the pore channel 2 as the first fluid - air, and load the material of the liquid silicon molten pool 1 as the second fluid - liquid silicon.

[0034] In a specific implementation, as a preferred embodiment of the present invention, step S2 specifically includes: S21. Solve for the laminar-horizontal two-phase flow field; S22, Coupled chemical reaction field and rare matter transport field; S23. Introduce a fluid heat transfer field and correct the temperature field through a reaction heat source; in this embodiment, the temperature in the fluid heat transfer field is set to... The heat source for the reaction is set as the heat source for the chemical field reaction.

[0035] S24. Couple two-phase flow horizontal collection, reactive flow dilute substance, and non-isothermal flow in a multiphysics field, and set the wetting angle of the first wetting wall 8 and the second wetting wall 9 as follows: .

[0036] In a specific implementation, as a preferred embodiment of the present invention, step S21 specifically includes: S211. Add a laminar flow field, which includes gravity. Set the pressure at the first inlet 3, the second inlet 4, and the outlet 5 to 0. Use the Navier-Stokes equations for incompressible fluids. The calculation formula is as follows:

[0037] in, Indicates the density of liquid silicon. Indicates the kinetic viscosity of liquid silicon. Represents the velocity field. g Represents the gravitational acceleration field. For pressure field, The tension at the liquid silicon interface, It is the identity matrix. t Let T represent time, and T denote transpose. S212. In the horizontal set function, the liquid silicon molten pool 1 is set as the second fluid and the pore channel 2 is set as the first fluid. The phase interface is dynamically tracked through the horizontal set function, and its calculation formula is as follows:

[0038] in, For level set functions, when When, it indicates that it is in the first phase, when "Time" indicates that it is in the second phase; These are the renormalization control parameters; These are parameters for controlling the phase interface thickness.

[0039] In a specific implementation, as a preferred embodiment of the present invention, step S22 specifically includes: S221. Add a reaction to a chemical field, and set up a reaction domain. and Reaction generation Its chemical reaction formula is:

[0040] S222. Calculate the reaction rate based on the Arrhenius equation. The calculation formula is as follows:

[0041] in, and The concentrations of carbon and silicon are respectively. and Here, represents the reaction order and the reaction rate constant. With temperature The relationship is:

[0042] in, Pre-exponential factor, For activation energy, Let be the ideal gas constant. T For temperature; S223. Setting transport properties in a rare matter transport field, including: The diffusion coefficient is set to 1.51 × 10⁻⁶. -14 ; Add a reaction and set the reaction domain. , , The initial concentration is 0, and the inlet is set. and The concentration was determined, and surface reaction boundary conditions were added, setting the reaction rate to the rate calculated in step S222 chemical field.

[0043] In a specific implementation, as a preferred embodiment of the present invention, step S3 specifically includes: S31. Using a mapped mesh, a mesh is generated for the entire multiphysics numerical model. S32. Simulate and solve the model using transient equations to obtain... - Reaction generation Concentration distribution (e.g.) Figure 3 (as shown) Reaction layer thickness distribution (e.g.) Figure 4 (as shown) and the curves showing the change in single capillary pore size with the shrinkage of the reaction layer (as shown) Figure 5 (as shown), and will The thickness of the reaction layer was compared and verified with experimental data from the literature (e.g.) Figure 6 (As shown).

[0044] Example In this embodiment, the simulated liquid The changes in the reaction layer during reactive infiltration in a two-dimensional single capillary are as follows: Figure 4As shown, the simulation process is as follows: Establish a physical field model: Upon entering the initial page of the COMSOL software, select "Model-oriented" for new creation, choose two-dimensional for the spatial dimension, select "Two-phase flow, horizontal set-laminar flow" under the fluid flow module for the physics field, and select to study transients with phase initialization.

[0045] Establish a geometric model: Create a rectangle in the geometry, and set its size to the width. ,high The location is , Create another rectangle and set its size to the width. ,high The location is , All objects are constructed into a union.

[0046] Set material parameters: Click on the completed 2D geometric model, and set the material of the liquid silicon molten pool 1 as liquid silicon. Physical property parameters: Set the pore channel 2 to the physical property parameters of air.

[0047] Set initial values, domain, and boundary conditions: In the laminar flow field, an incompressible fluid is selected and gravity is included. The initial values ​​of the velocity field and pressure field are 0. The first inlet 3, the second inlet 4, and the outlet 5 are set as pressure boundary conditions with a pressure of 0. In the horizontal set model, one initial value is set as the first fluid and the domain is selected as the pore channel 2. The other initial value is set as the second fluid and the domain is selected as the liquid silicon molten pool 1. The horizontal set conditions at the first inlet 3 and the second inlet 4 are set as the second fluid. Add a reaction to the chemical field, and add a chemical reaction formula to reaction domain 2. "Set the reaction rate, check the box to use the Arrhenius expression for the reaction rate constant, and set..." molar mass ,set up molar mass ,set up molar mass ; In a rare matter transport field, a transport property is set, with a diffusion coefficient of... Add a reaction and set reaction domain 2. 、 、 The initial concentration is 0, and the first inlet 3 and the second inlet are set. The inflow concentration is set on the carbon matrix surface. The concentration was determined, and surface reaction boundary conditions were added, setting the reaction rate to the rate calculated in step S222 chemical field.

[0048] In the fluid heat transfer field, the temperature is set to... The heat source for the reaction is set as the heat source for the chemical field reaction.

[0049] Grid generation: A mapped mesh is used to generate a mesh for the entire model; Solve the calculation: The solver uses transient calculations. At the physics interface, select laminar flow, horizontal collection, chemical, rare matter transport and fluid heat transfer. In multiphysics coupling, select "two-phase flow, horizontal collection", "two-phase flow, rare matter", "non-isothermal flow" and wetted wall.

[0050] The above-described embodiments of the operation construction can be obtained Figure 3 The generation Concentration distribution Figure 4 of Layer thickness distribution, Figure 5 The curve of single capillary pore size change with the shrinkage of the reaction layer and Figure 6 of The simulation and experimental comparison chart of layer thickness shows that the generated... The layer thickness exhibits a non-linear, non-uniform growth, and the rate of change in reactant concentration varies at different stages of the reaction mechanism. The stages are controlled according to different reaction mechanisms. The concentration evolution curve shows a shift from a dissolution-precipitation mechanism to a diffusion mechanism, with a significant decrease in the reaction rate.

[0051] In summary, this invention uses COMSOL software for two-dimensional modeling and simplifies the model to simulate liquid silicon in... / The reactive melting infiltration process in porous materials was investigated, revealing the growth and mechanism of the reaction layer. This approach saves computational time while ensuring model accuracy. The model can predict pore structure changes during the reactive melting infiltration process based on the simulated reaction layer variation patterns, providing a basis for targeted control and optimization of preform pore parameters. The process parameters provide theoretical support.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A numerical simulation method for reactive melting and infiltration processes based on COMSOL multiphysics coupling, characterized in that, include: S1. Construct a simplified liquid silicon infiltration model and simulate it using a two-dimensional single capillary equivalent model. / The porous structure of porous materials; S2. Based on the liquid silicon melting and infiltration model, the laminar-horizontal two-phase flow field, chemical reaction field, rare matter transfer field and fluid heat transfer field are coupled to form a multiphysics numerical model. S3. Obtain the liquid silicon penetration height curve through transient solution. Concentration distribution and pore structure evolution data.

2. The numerical simulation method for reactive melting and infiltration processes based on COMSOL multiphysics coupling according to claim 1, characterized in that, In step S1, according to / The complex structure of multi-level pores between / within fiber bundles in porous bodies simplifies the local cannula pores into a two-dimensional axisymmetric single capillary equivalent model, specifically including: S11. A two-dimensional single capillary model is used to construct the geometric model, which consists of a liquid silicon molten pool and a porous flow channel. The width of the liquid silicon molten pool is 80 and the height is 20, and the width of the porous flow channel is 40 and the height is 100. S12. Set material properties, load the pore channel material as the first fluid - air, and load the liquid silicon molten pool material as the second fluid - liquid silicon.

3. The numerical simulation method for reactive melting and infiltration processes based on COMSOL multiphysics coupling according to claim 1, characterized in that, Step S2 specifically includes: S21. Solve for the laminar-horizontal two-phase flow field; S22, Coupled chemical reaction field and rare matter transport field; S23. Introduce a fluid heat transfer field and correct the temperature field through a reaction heat source; S24. Couple two-phase flow horizontal collection, reactive flow of dilute substance, and non-isothermal flow in a multiphysics field, and set the wetting angle of the wetting wall as... .

4. The numerical simulation method for reactive melting and infiltration processes based on COMSOL multiphysics coupling according to claim 3, characterized in that, Step S21 specifically includes: S211. Add a laminar flow field, which includes gravity. Set the inlet and outlet pressures to 0 and use the Navier-Stokes equations for incompressible fluids. The calculation formula is as follows: in, Indicates the density of liquid silicon. Indicates the kinetic viscosity of liquid silicon. Represents the velocity field. g Represents the gravitational acceleration field. For pressure field, The tension at the liquid silicon interface. It is the identity matrix. t Let T represent time, and T denote transpose. S212. In the horizontal set function, the molten silicon pool is set as the second fluid and the pore channel as the first fluid. The phase interface is dynamically tracked through the horizontal set function, and its calculation formula is as follows: in, For level set functions, when When, it indicates that it is in the first phase, when "Time" indicates that it is in the second phase; These are the renormalization control parameters; These are parameters for controlling the phase interface thickness.

5. The numerical simulation method for reactive melting and infiltration processes based on COMSOL multiphysics coupling according to claim 3, characterized in that, Step S22 specifically includes: S221. Add a reaction to a chemical field, and set up a reaction domain. and Reaction generation Its chemical reaction formula is: S222. Calculate the reaction rate based on the Arrhenius equation. The calculation formula is as follows: in, and The concentrations of carbon and silicon are respectively. and Here, represents the reaction order and the reaction rate constant. With temperature The relationship is: in, Pre-exponential factor, For activation energy, Let be the ideal gas constant. T For temperature; S223. Setting transport properties in a rare matter transport field, including: The diffusion coefficient is set to 1.51 × 10⁻⁶. -14 ; Add a reaction and set the reaction domain. , , The initial concentration is 0, and the inlet is set. The inflow concentration is set on the carbon matrix surface. The concentration was determined, and surface reaction boundary conditions were added, setting the reaction rate to the rate calculated in step S222 chemical field.

6. The numerical simulation method for reactive melting and infiltration processes based on COMSOL multiphysics coupling according to claim 1, characterized in that, Step S3 specifically includes: S31. Using a mapped mesh, a mesh is generated for the entire multiphysics numerical model. S32. Simulate and solve the model using transient equations to obtain... - Reaction generation Concentration distribution Curves showing the changes in reaction layer thickness distribution and single capillary pore size as the reaction layer shrinks.

7. The numerical simulation method for reactive melting and infiltration processes based on COMSOL multiphysics coupling according to claim 6, characterized in that, The Reaction layer thickness distribution used for prediction / The critical conditions for pore closure in porous bodies guide the optimization of pore parameters in preforms and the control of melting infiltration process parameters.

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