SiC / SiBCN-Y2O3 composite material and preparation method thereof

Abstract

The invention discloses a SiC / SiBCN-Y2O3 composite material and a preparation method thereof, the SiC / SiBCN-Y2O3 composite material takes silicon carbide fiber as a reinforcement body, a SiBCN precursor and nano Y2O3 particles are adopted to prepare a SiBCN-Y2O3 multiphase ceramic precursor, and the densified SiC / SiBCN-Y2O3 composite material is prepared through a multi-round PIP process. According to the prepared multiphase ceramic precursor, the proportion of all components can be regulated and controlled, the SiBCN precursor and nano Y2O3 particles are quantitatively introduced in the dipping process, and the dispersion uniformity of a SiBCN phase and a Y2O3 phase in a matrix is improved; and the oxidation resistance of the composite material is remarkably improved by forming the yttrium silicate oxidation layer in the high-temperature oxidation process. The composite material has excellent mechanical properties and high-temperature long-time oxidation resistance, and can serve as a thermal structure material in high-temperature oxidation and bearing environments.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of thermal structural composites and preparation, and particularly relates to a SiC / SiBCN-Y2O3 composite material and a preparation method thereof. BACKGROUND

[0002] Silicon carbide fiber reinforced ceramic matrix composites have the advantages of high temperature resistance, low density, oxidation resistance, etc., overcome the shortcomings of high density of metal materials, high brittleness of structural ceramics, poor oxidation resistance of carbon / carbon composites, and poor creep resistance of oxide ceramics, and are one of important materials for improving the service performance of thermal end and thermal structure components of aircraft in an oxygen environment. However, with the continuous increase of the Mach number of the aircraft, the aerodynamic heating problem of the thermal end and thermal structure material is becoming more and more serious, especially in the oxygen environment above 1200℃, the oxidation rate of SiC and SiBCN ceramic matrix increases significantly, which further leads to the decrease of mechanical properties, the increase of brittleness and the decrease of reliability of the composite material. Therefore, in order to meet the long-term use requirement in the oxygen environment, the oxidation resistance of silicon carbide fiber reinforced ceramic matrix composites needs to be improved.

[0003] In order to improve the high-temperature and long-time oxidation resistance of silicon carbide fiber reinforced ceramic matrix composites, introducing high-temperature oxidation-resistant components into the matrix becomes an important idea. Among them, rare earth oxide Y2O3 has the advantages of high melting point and phase stability, and can form yttrium silicate solid solution with SiO2, which has low oxygen permeability, low thermal expansion coefficient, low thermal conductivity and thermodynamic stability. At the same time, the oxidation of SiBCN ceramic matrix can generate a borosilicate oxide layer with self-healing ability, and the selection of SiBCN-Y2O3 as the matrix is expected to improve the oxidation resistance of silicon carbide fiber reinforced ceramic matrix composites. However, in the traditional preparation process of ceramic matrix composites, the preparation method of SiBCN-Y2O3 matrix has limitations, such as the difficulty of quantitative introduction of Y2O3 in the slurry impregnation process, and the easy formation of closed pores in the composite material, which reduces the densification degree of the composite material; the sol-gel impregnation and pyrolysis process is easy to cause the matrix to separate, which reduces the dispersion uniformity and performance stability of each phase in the matrix.

[0004] In summary, in view of the insufficient high-temperature oxidation resistance of existing silicon carbide fiber reinforced ceramic matrix composites and the limitations of the preparation process, new SiBCN-Y2O3 matrix thermal structure composite material technology research needs to be carried out. SUMMARY

[0005] The present application provides a SiC / SiBCN-Y2O3 composite material and a preparation method thereof, which aims to improve the high-temperature oxidation resistance.

[0006] In a first aspect, a SiC / SiBCN-Y2O3 composite material is provided, the composite material taking silicon carbide fibers as reinforcing bodies, a SiBCN-Y2O3 composite ceramic precursor being prepared from a SiBCN precursor and nano Y2O3 particles, a densified SiC / SiBCN-Y2O3 composite material being prepared through a multi-round PIP process, a yttrium silicate oxide layer being formed on the surface of the SiC / SiBCN-Y2O3 composite material, and the SiBCN phase and the Y2O3 phase being uniformly distributed in the matrix of the SiC / SiBCN-Y2O3 composite material.

[0007] With reference to the first aspect, in some implementations of the first aspect, the SiBCN phase of the pyrolytic ceramic product of the SiBCN precursor comprises: Si-40-50wt%, N-18-28wt%, C-15-25wt%, B-8-12wt%, and O-1-3wt%.

[0008] With reference to the first aspect, in some implementations of the first aspect, the ratio of the Y2O3 particles to the SiBCN precursor is 0.02-0.2.

[0009] With reference to the first aspect, in some implementations of the first aspect, the particle size of the Y2O3 particles is 10-500nm.

[0010] In a second aspect, a preparation method of the SiC / SiBCN-Y2O3 composite material according to any one of the implementations of the first aspect is provided, and the method comprises:

[0011] (1) adding the nano Y2O3 particles to the SiBCN precursor to uniformly mix the nano Y2O3 particles and the SiBCN precursor, and obtaining a SiBCN-Y2O3 composite ceramic precursor;

[0012] (2) taking the silicon carbide fibers as reinforcing bodies to prepare a silicon carbide fiber fabric preform;

[0013] (3) placing the silicon carbide fiber fabric preform in a heat treatment device, and under the protection of an inert gas, heating to 400-1000℃ to remove the organic matter inside the silicon carbide fiber fabric preform and clean the fiber surface;

[0014] (4) placing the silicon carbide fiber fabric preform after the organic matter is removed in a chemical vapor deposition furnace to deposit an interface layer on the surface of the silicon carbide fibers;

[0015] (5) using the SiBCN-Y2O3 composite ceramic precursor in (1) to impregnate and solidify the silicon carbide fiber fabric preform containing the interface layer, and then placing the solidified blank in a heat treatment furnace to perform high-temperature treatment under the protection of an inert gas;

[0016] (6) repeating step (5) until the single round weight gain rate is less than 0.5%, and stopping the compounding to obtain the SiC / SiBCN-Y2O3 composite material.

[0017] With reference to the second aspect, in some implementations of the second aspect, step (1) satisfies at least one of the following:

[0018] The viscosity of the SiBCN precursor ranges from 40 cP to 4000 cP.

[0019] The preparation temperature of the SiBCN-Y2O3 composite ceramic precursor ranges from 20°C to 100°C.

[0020] With reference to the second aspect, in some implementations of the second aspect, step (2) satisfies at least one of the following:

[0021] The fiber material of the silicon carbide fiber is any one of the following: Nicalon, Hi-Nicalon, Hi-Nicalon Type-S, Tyranno ZMI, Tyranno SA3, Tyranno SA4, Sylramic, Sylramic-iBN, Cansas 3200, Cansas 3300, KD-S, KD-SA, Shincolon-II.

[0022] The reinforcing structure of the silicon carbide fiber is any one of the following: one-dimensional fiber reinforcement, two-dimensional fiber reinforcement, three-dimensional fiber reinforcement, and chopped fiber mat.

[0023] With reference to the second aspect, in some implementations of the second aspect, step (4) satisfies at least one of the following:

[0024] The interface layer is any one of the following: PyC, BN, (PyC / SiC)n, (BN / SiC)n, where n is a natural number and 1≤n≤5.

[0025] The thickness of the interface layer ranges from 20 nm to 2 μm.

[0026] With reference to the second aspect, in some implementations of the second aspect, in step (5), the silicon carbide fiber fabric preform is placed in a container and heated to a temperature ranging from 50°C to 120°C and vacuumized to a pressure ranging from -0.1 MPa to 0.05 MPa, and then the SiBCN-Y2O3 composite ceramic precursor at a temperature ranging from 50°C to 120°C is infiltrated into the silicon carbide fiber fabric preform, and the infiltration time ranges from 0.5 hour to 3 hours; and then high-pressure infiltration is performed under a pressure ranging from 1 MPa to 5 MPa for 0.5 hour to 3 hours.

[0027] With reference to the second aspect, in some implementations of the second aspect, in the step (5), the curing temperature is 170-280 DEG C, and the high-temperature treatment temperature is 800-1400 DEG C.

[0028] Compared with the prior art, the scheme provided by the application has at least the following beneficial technical effects:

[0029] (1) In the preparation process of the SiBCN-Y2O3 composite ceramic precursor, the viscosity of the SiBCN precursor is controlled by changing the temperature, and the high molecular dispersion mechanism of the SiBCN precursor is fully utilized to improve the dispersion uniformity and stability of the nano Y2O3 particles in the SiBCN precursor.

[0030] (2) Using the SiBCN-Y2O3 composite ceramic precursor as the impregnation liquid, the vacuum-pressure impregnation technology can be used to simultaneously and quantitatively introduce the SiBCN precursor and nano Y2O3 particles into the fiber preform, avoiding the poor performance and large dispersion of the composite material caused by uneven dispersion of the phases in the matrix.

[0031] (3) The SiC / SiBCN-Y2O3 composite material can form a yttrium silicate oxidation layer on the surface during high-temperature and long-time oxidation, avoiding the severe oxidation of the fibers and the matrix inside the composite material, and effectively improving the high-temperature oxidation resistance and mechanical strength retention rate of the composite material. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 It is a micrograph of a SiC / SiBCN-Y2O3 composite material.

[0033] Figure 2 It is a bending strength-strain curve diagram of the SiC / SiBCN-Y2O3 composite material before and after oxidation.

[0034] Figure 3 It is a fracture morphology diagram of the SiC / SiBCN-Y2O3 composite material before and after oxidation: (a) before oxidation; (b) 1500 DEG C for 30 hours. DETAILED DESCRIPTION

[0035] The application will be further described in detail below with reference to the drawings and specific examples.

[0036] The application provides a SiC / SiBCN-Y2O3 composite material. The composite material is prepared by using a silicon carbide fiber as a reinforcing body, using a SiBCN precursor and nano Y2O3 particles to prepare a SiBCN-Y2O3 composite ceramic precursor, and preparing a densified SiC / SiBCN-Y2O3 composite material through multiple PIP processes. Figure 1As shown, the SiBCN phase and the Y2O3 phase are uniformly distributed in the matrix, and the high-temperature oxidation resistance can be fully exerted.

[0037] In some embodiments, the SiBCN precursor can be prepared by patents 201811249968.2 and 201610362812.X.

[0038] In some embodiments, in the SiC / SiBCN-Y2O3 composite material, the SiBCN phase composition of the SiBCN precursor pyrolysis ceramic product is: Si-40-50wt%, N-18-28wt%, C-15-25wt%, B-8-12wt%, and O-1-3wt%.

[0039] In some embodiments, the ratio of Y2O3 particles to SiBCN precursor is 0.02-0.2.

[0040] In some embodiments, the particle size of the Y2O3 particles is 10-500nm.

[0041] The application also provides a preparation method of the SiC / SiBCN-Y2O3 composite material, and the steps are as follows.

[0042] (1) A certain proportion of nano Y2O3 particles is added to the SiBCN precursor, and the uniform mixing of the nano Y2O3 particles and the SiBCN precursor is realized by controlling the viscosity of the SiBCN precursor at a certain temperature, to obtain a SiBCN-Y2O3 composite ceramic precursor.

[0043] (2) A silicon carbide fiber fabric preform of a certain size is prepared by taking silicon carbide fiber as a reinforcing body.

[0044] (3) The silicon carbide fiber fabric preform is placed in a heat treatment equipment, and under the protection of inert gas, the temperature is raised to 400-1000℃, and the organic matter such as sizing agent inside the silicon carbide fiber fabric preform is removed, so that the fiber surface is clean.

[0045] (4) The silicon carbide fiber fabric preform after removing the organic matter is placed in a chemical vapor deposition furnace, and a certain thickness of an interface layer is deposited on the surface of the silicon carbide fiber.

[0046] (5) The SiBCN-Y2O3 composite ceramic precursor in (1) is used to impregnate and solidify the silicon carbide fiber fabric preform containing the interface layer under vacuum and a certain pressure, and then the solidified blank is placed in a heat treatment furnace for high-temperature treatment under the protection of inert gas.

[0047] In the impregnation process, SiBCN precursor and nano Y2O3 particles can be introduced simultaneously and quantitatively, improving the dispersion uniformity of each phase in the matrix. In addition, the composition of the composite matrix can be controlled by changing the ratio of SiBCN-Y2O3 composite ceramic precursor components. During high-temperature oxidation, a yttrium silicate oxide layer is formed on the surface of the SiC / SiBCN-Y2O3 composite, significantly improving the oxidation resistance of the composite.

[0048] (6) Cycle step (5), when the single round weight gain rate is less than 0.5%, the compounding can be stopped. The obtained composite is SiC / SiBCN-Y2O3 composite.

[0049] In step (1), the SiBCN precursor can be prepared by patent 201811249968.2, 201610362812.X.

[0050] In step (1), the viscosity of the SiBCN precursor is 40 cP-4000 cP.

[0051] In step (1), the ratio of Y2O3 particles to SiBCN precursor is 0.02-0.2.

[0052] In step (1), the particle size of Y2O3 particles is 10 nm-500 nm.

[0053] In step (1), the preparation temperature of SiBCN-Y2O3 composite ceramic precursor is 20℃-100℃.

[0054] In step (2), the fiber material and reinforcement structure of silicon carbide fiber have no strict requirements, and the fiber material of silicon carbide fiber can be Nicalon, Hi-Nicalon, Hi-Nicalon Type-S, Tyranno ZMI, Tyranno SA3, Tyranno SA4, Sylramic, Sylramic-iBN, Cansas 3200, Cansas 3300, KD-S, KD-SA, Shincolon-II, etc. The reinforcement structure of silicon carbide fiber includes one-dimensional, two-dimensional, three-dimensional fiber reinforcement and chopped fiber mat, etc.

[0055] In step (4), the interface layer includes but is not limited to PyC, BN, (PyC / SiC)n, (BN / SiC)n, where n is a natural number, and 1≤n≤5.

[0056] In step (4), the thickness of the interface layer is 20 nm-2 μm.

[0057] In the step (5), the silicon carbide fiber fabric preform is placed in a container and heated to 50-120°C and vacuumized to -0.1-0.05 MPa, and then the SiBCN-Y2O3 composite ceramic precursor at 50-120°C is impregnated into the silicon carbide fiber fabric preform, and the impregnation time is 0.5-3 hours. Then high pressure impregnation is carried out under a pressure of 1-5 MPa for 0.5-3 hours.

[0058] In the step (5), the curing temperature is 170-280°C, and the high temperature treatment temperature is 800-1400°C.

[0059] Example 1

[0060] (1) 1000 g of SiBCN precursor is warmed to 30°C and kept for 10 min, and the viscosity is measured to be 3720 cP. Then 30 g of Y2O3 nanoparticles with a particle size of 20 nm is added to the SiBCN precursor and mechanically stirred for 1 hour, wherein the ratio of Y2O3 nanoparticles to SiBCN precursor is 0.03:1.

[0061] (2) A 2.5D fabric preform with a size of 200 mm x 200 mm x 5 mm is prepared using Hi-Nicalon silicon carbide fiber fabric as the reinforcing body, wherein the fiber volume ratio of the warp direction to the weft direction is 1:0.5, and the fiber volume content is 40%.

[0062] (3) The silicon carbide fiber fabric preform is placed in a heat treatment device, and under nitrogen protection, it is warmed to 500°C and kept for 4 hours to remove organic matter such as sizing agent inside the fabric, so that the fiber surface is clean.

[0063] (4) The silicon carbide fiber fabric after removal of organic matter is placed in a chemical vapor deposition furnace, and a PyC interface layer with a thickness of 50 nm is deposited on the surface of the silicon carbide fiber.

[0064] (5) The SiBCN-Y2O3 composite ceramic precursor in (1) is used to impregnate the silicon carbide fiber fabric preform containing the PyC interface layer at 30°C under a vacuum degree of -0.1 MPa for 40 min, and then high pressure impregnation is carried out at 30°C under a pressure of 1 MPa for 40 min; the silicon carbide fiber fabric preform after vacuum-pressure impregnation is cured and crosslinked at 220°C for 1 hour, and then placed in a heat treatment furnace and high temperature treated at 900°C under nitrogen protection for 1 hour.

[0065] (6) After 10 cycles of step (5), the single round weight gain rate is less than 0.5%, and the obtained composite material is a SiC / SiBCN-Y2O3 composite material.

[0066] In this example, the density of the obtained composite material is 2.29 g / cm3 , the bending strength is 347 MPa, the bending strength is 305 MPa after 1300℃ oxidation for 20 hours, and the strength retention rate is 88%.

[0067] Example 2

[0068] (1) 1000g of SiBCN precursor was heated to 60℃ and kept for 10min, and the viscosity was measured to be 440cP. 100g of nano Y2O3 particles with a particle size of 300nm was added to the SiBCN precursor and mechanically stirred for 1 hour, wherein the ratio of Y2O3 particles to SiBCN precursor was 0.1:1.

[0069] (2) A 100mmx100mmx5mm fabric preform was prepared using Cansas 3300 silicon carbide fiber cloth laminated stitched fabric as the reinforcing body, wherein the fiber volume content was 30%.

[0070] (3) The silicon carbide fiber fabric preform was placed in a heat treatment equipment, and under the protection of nitrogen, it was heated to 600℃ and kept for 3 hours to remove the organic matter such as sizing agent inside the fabric, so that the fiber surface was clean.

[0071] (4) The silicon carbide fiber fabric after removing the organic matter was placed in a chemical vapor deposition furnace to deposit a BN interfacial layer with a thickness of 200nm on the surface of the silicon carbide fiber.

[0072] (5) The SiBCN-Y2O3 composite ceramic precursor in (1) was used to impregnate the silicon carbide fiber fabric preform containing the BN interfacial layer at 60℃ under a vacuum degree of-0.05MPa for 1 hour, and then high-pressure impregnation was carried out at 60℃ under a pressure of 3MPa for 1 hour; the silicon carbide fiber fabric preform after vacuum-pressure impregnation was placed in a heat treatment furnace and treated at 1200℃ under the protection of nitrogen for 1 hour.

[0073] (6) After 8 cycles of step (5), the single-cycle weight gain rate was less than 0.5%, and the obtained composite material was SiC / SiBCN-Y2O3 composite material.

[0074] In this example, the density of the obtained composite material is 2.35g / cm 3 , the bending strength is 337 MPa, as shown in Figure 2 , the bending strength is 254 MPa after 1500℃ oxidation for 30 hours, and the strength retention rate is 76%, Figure 3 The fracture morphology shown in

[0075] Example 3

[0076] (1) 1000g SiBCN precursor was heated to 90℃ and kept for 10min, the viscosity was measured to be 98cP, and then 150g Y2O3 nanoparticles with a particle size of 500nm were added into the SiBCN precursor and mechanically stirred for 1h, wherein the ratio of Y2O3 nanoparticles to SiBCN precursor was 0.15:1.

[0077] (2) KD-SA silicon carbide fiber three-dimensional orthogonal structure fabric was used as a reinforcing body to prepare a fabric preform with a size of 150mm×150mm×10mm, wherein the fiber volume content was 50%.

[0078] (3) The silicon carbide fiber fabric preform was placed into a heat treatment device, and was heated to 800℃ and kept for 2h under nitrogen protection, so as to remove organic matters such as a sizing agent in the fabric and make the fiber surface clean.

[0079] (4) The silicon carbide fiber fabric after removing the organic matters was placed into a chemical vapor deposition furnace, and a (BN / SiC) interface layer with a thickness of 600nm was deposited on the surface of the silicon carbide fiber.

[0080] (5) The SiBCN-Y2O3 composite ceramic precursor in (1) was used to impregnate the silicon carbide fiber fabric preform containing the (BN / SiC) interface layer for 1.5h under the condition of 90℃ and a vacuum degree of-0.01MPa, and then was subjected to high-pressure impregnation for 1.5h under the condition of 60℃ and a pressure of 4MPa; the silicon carbide fiber fabric preform after vacuum-pressure impregnation was placed into a heat treatment furnace and was subjected to high-temperature treatment for 1h under the condition of 1300℃ and nitrogen protection.

[0081] (6) After 9 cycles of step (5), the weight gain rate of a single cycle was less than 0.5%, and the obtained composite material was a SiC / SiBCN-Y2O3 composite material.

[0082] In this embodiment, the density of the obtained composite material was 2.43g / cm 3 , the bending strength was 413MPa, the bending strength after oxidation for 20h at 1500℃ was 358MPa, and the strength retention rate was 87%.

[0083] Although the present application is disclosed with the preferred embodiments as above, it is not intended to limit the present application, and any person skilled in the art can make possible changes and modifications without departing from the spirit and scope of the present application, therefore, the protection scope of the present application should be defined by the scope defined by the claims of the present application.

Claims

1. A SiC / SiBCN-Y2O3 composite material, characterized in that, The composite material uses silicon carbide fiber as reinforcement. A SiBCN-Y2O3 multiphase ceramic precursor is prepared by using SiBCN precursor and nano-Y2O3 particles. A densified SiC / SiBCN-Y2O3 composite material is prepared by multiple rounds of PIP process. A yttrium silicate oxide layer is formed on the surface of the SiC / SiBCN-Y2O3 composite material. The SiBCN phase and Y2O3 phase are uniformly distributed in the matrix of the SiC / SiBCN-Y2O3 composite material.

2. The composite material according to claim 1, characterized in that, The SiBCN phase composition of the SiBCN precursor pyrolysis ceramic product is: Si-40~50wt%, N-18~28wt%, C-15~25wt%, B-8~12wt%, O-1~3wt%.

3. The composite material according to claim 1, characterized in that, The ratio of Y2O3 particles to SiBCN precursor is 0.02 to 0.

2.

4. The composite material according to claim 1, characterized in that, The particle size of Y2O3 particles ranges from 10 nm to 500 nm.

5. A method for preparing a SiC / SiBCN-Y2O3 composite material as described in any one of claims 1 to 4, characterized in that, include: (1) Add nano Y2O3 particles to SiBCN precursor to make the nano Y2O3 particles and SiBCN precursor uniformly mixed to obtain SiBCN-Y2O3 multiphase ceramic precursor. (2) A silicon carbide fiber fabric preform was prepared using silicon carbide fiber as reinforcement. (3) Place the silicon carbide fiber fabric preform into a heat treatment device and heat it to 400℃~1000℃ under inert gas protection to remove the organic matter inside the silicon carbide fiber fabric preform and clean the fiber surface. (4) Place the silicon carbide fiber fabric preform after removing organic matter into a chemical vapor deposition furnace to deposit an interface layer on the surface of silicon carbide fibers. (5) Using the SiBCN-Y2O3 multiphase ceramic precursor in (1), the silicon carbide fiber fabric preform containing the interface layer is impregnated and cured, and then the cured blank is placed in a heat treatment furnace and subjected to high temperature treatment under inert gas protection. (6) Repeat step (5) until the weight gain rate of a single round is less than 0.5%, then stop the compounding process to obtain the SiC / SiBCN-Y2O3 composite material.

6. The preparation method according to claim 5, characterized in that, Step (1) satisfies at least one of the following: The viscosity range of the SiBCN precursor is 40 cP-4000 cP; The preparation temperature of SiBCN-Y2O3 multiphase ceramic precursor is 20℃~100℃.

7. The preparation method according to claim 5, characterized in that, Step (2) satisfies at least one of the following: The fiber material of silicon carbide fiber is any one of the following: Nicalon, Hi-Nicalon, Hi-Nicalon Type-S, Tyranno ZMI, Tyranno SA3, Tyranno SA4, Sylramic, Sylramic-iBN, Cansas 3200, Cansas3300, KD-S, KD-SA, Shincolon-II; The reinforcing structure of silicon carbide fibers can be any of the following: one-dimensional fiber reinforcement, two-dimensional fiber reinforcement, three-dimensional fiber reinforcement, and chopped fiber mat.

8. The preparation method according to claim 5, characterized in that, Step (4) satisfies at least one of the following: The interface layer type is any one of the following: PyC, BN, (PyC / SiC)n, (BN / SiC)n, where n is a natural number and 1≤n≤5; The thickness of the interface layer is 20nm to 2μm.

9. The preparation method according to claim 5, characterized in that, In step (5), the silicon carbide fiber fabric preform is placed in a container and heated to 50℃~120℃ and evacuated to -0.1MPa~0.05MPa. Then, the SiBCN-Y2O3 multiphase ceramic precursor at a temperature of 50℃~120℃ is impregnated into the silicon carbide fiber fabric preform for 0.5 hours to 3 hours. Then, high-pressure impregnation is carried out for 0.5 hours to 3 hours under a pressure of 1MPa~5MPa.

10. The preparation method according to claim 5, characterized in that, In step (5), the curing temperature is 170℃~280℃, and the high-temperature treatment temperature is 800℃~1400℃.

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