Method for treating a flow guide cylinder

Abstract

The application discloses a kind of processing methods of flow guide tube, comprising: deposition step: the flow guide tube is placed in hydrocarbon gas deposition and forms pyrolytic carbon layer;Impregnation step: the flow guide tube with pyrolytic carbon layer is placed in precursor liquid and is impregnated;High-temperature processing step: after the flow guide tube after impregnation is placed in first atmosphere environment and is treated at first temperature 1-4h;The flow guide tube after being treated at first temperature is placed in second atmosphere environment and is treated at second temperature 5-30min;The flow guide tube after being treated at second temperature is placed in third atmosphere environment and is treated at third temperature 1-4h;Precursor liquid includes polycarbosilane, SiC, solvent;First temperature is 120-200 DEG C, and first atmosphere environment includes inert atmosphere or vacuum environment;Second temperature is 800-1200 DEG C, and second atmosphere environment includes oxidizing atmosphere;Third temperature is 1300-1500 DEG C, and third atmosphere environment includes inert atmosphere or vacuum environment.The flow guide tube treated by above-mentioned method, surface is not easy to oxidize damage, avoid surface cracking, drop piece.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of semiconductor, and particularly relates to a processing method of a flow guide cylinder. BACKGROUND

[0002] Semiconductor has become a very important field, in the semiconductor field, a crystal bar is often drawn through a single crystal furnace, and airflow and temperature field in the single crystal furnace have an important influence on the prepared crystal bar, therefore, a flow guide cylinder is arranged in the single crystal furnace to guide the airflow in the single crystal furnace, so that the airflow can flow according to a required airflow field, and the temperature field and the airflow field are controlled through the flow guide cylinder, so that the airflow field and the temperature field are stable. The existing flow guide cylinder is often prepared from carbon-carbon composite material, and the oxidation resistance of the flow guide cylinder is not high in the use process, the surface of the flow guide cylinder is easy to be oxidized and damaged, and even surface cracking and block falling may occur, which affects the use of the flow guide cylinder and further affects the preparation quality of the crystal bar. SUMMARY

[0003] The purpose of the embodiment of the present application is to provide a processing method of a flow guide cylinder, so as to solve the problem that the surface oxidation resistance of the flow guide cylinder is not high and the surface is easy to be damaged.

[0004] The embodiment of the present application provides a processing method of a flow guide cylinder, which comprises the following steps.

[0005] A deposition step of placing the flow guide cylinder in a hydrocarbon gas to form a pyrolytic carbon layer through deposition;

[0006] An immersion step of placing the flow guide cylinder with the pyrolytic carbon layer in a precursor liquid for immersion;

[0007] A high-temperature treatment step of placing the immersed flow guide cylinder in a first atmosphere environment for treatment at a first temperature for 1-4 hours;

[0008] Placing the flow guide cylinder treated at the first temperature in a second atmosphere environment for treatment at a second temperature for 5-30 minutes;

[0009] Placing the flow guide cylinder treated at the second temperature in a third atmosphere environment for treatment at a third temperature for 1-4 hours;

[0010] The precursor liquid comprises polycarbosilane, SiC and a solvent.

[0011] The first temperature is 120-200 DEG C, and the first atmosphere environment comprises an inert atmosphere or a vacuum environment.

[0012] The second temperature is 800-1200 DEG C, and the second atmosphere environment comprises an oxidizing atmosphere.

[0013] The third temperature is 1300-1500 DEG C, and the third atmosphere environment comprises an inert atmosphere or a vacuum environment.

[0014] Optionally, the step of placing the flow guide cylinder in the hydrocarbon gas to deposit the pyrolytic carbon layer comprises:

[0015] placing the flow guide cylinder in the hydrocarbon gas to deposit the pyrolytic carbon layer at 900-1300℃ for 2-6h.

[0016] Optionally, the step of placing the flow guide cylinder with the pyrolytic carbon layer in the precursor liquid to soak comprises:

[0017] placing the flow guide cylinder with the pyrolytic carbon layer in the precursor liquid to soak in vacuum or inert environment for 1-4h.

[0018] Optionally, the mass ratio of polycarbosilane, SiC and solvent in the precursor liquid is (1-4):(0.5-1.5):(3-7).

[0019] Optionally, the precursor liquid further comprises a silicate mineral, and the silicate mineral comprises at least one of mullite and modified mullite.

[0020] Optionally, the precursor liquid further comprises a silicate mineral, and the silicate mineral is modified mullite, and the mass ratio of modified mullite, polycarbosilane, SiC and solvent in the precursor liquid is (0.5-1.5):(1-4):(0.5-1.5):(3-7).

[0021] Optionally, the preparation method of the modified mullite comprises:

[0022] placing the mullite in an inert atmosphere and treating at 700-900℃ for 1-3h;

[0023] cooling and grinding the treated mullite;

[0024] cleaning the ground mullite;

[0025] stirring and mixing the cleaned mullite with yellow dextrin, and drying to obtain the modified mullite.

[0026] Optionally, the mass ratio of mullite and yellow dextrin is (10-20):(1-4).

[0027] Optionally, the step of placing the soaked flow guide cylinder in the first atmosphere environment and treating at the first temperature for 1-4h comprises:

[0028] placing the soaked flow guide cylinder in the first atmosphere environment, warming from room temperature to the first temperature at a first warming rate, and treating at the first temperature for 1-4h;

[0029] the first warming rate is 3-8℃ / min; and / or

[0030] the step of placing the flow guide cylinder treated at the first temperature into a second atmosphere environment and treating at a second temperature for 5-30 min includes:

[0031] the step of placing the flow guide cylinder treated at the first temperature into a second atmosphere environment and treating at a second temperature for 5-30 min includes:

[0032] the second temperature increasing rate is 15-25℃ / min; and / or

[0033] the step of placing the flow guide cylinder treated at the second temperature into a third atmosphere environment and treating at a third temperature for 1-4 h includes:

[0034] the step of placing the flow guide cylinder treated at the second temperature into a third atmosphere environment and treating at a third temperature for 1-4 h includes:

[0035] the third temperature increasing rate is 3-8℃ / min.

[0036] optionally, the surface of the flow guide cylinder has a carbon layer; and / or

[0037] the flow guide cylinder treated by the high-temperature treatment step is repeatedly subjected to the impregnation step and the high-temperature treatment step; and / or

[0038] the hydrocarbon gas includes at least one of methane, ethane, propylene, propane, and cyclopropane; and / or

[0039] the solvent includes at least one of an alkyl alcohol, a hydrocarbon solvent, and a ketone solvent.

[0040] In the processing method of the guide cone, the guide cone is placed in a hydrocarbon gas to deposit a pyrolytic carbon layer, the guide cone with the pyrolytic carbon layer is placed in a precursor liquid to be impregnated, the impregnated guide cone is placed in a first atmosphere at a first temperature to be processed, then placed in a second atmosphere at a second temperature to be processed, and then placed in a third atmosphere at a third temperature to be processed, and the precursor liquid comprises polycarbosilane, SiC, and a solvent. The guide cone is placed in a hydrocarbon gas to deposit a pyrolytic carbon layer, and after the guide cone with the pyrolytic carbon layer is impregnated by the precursor liquid and processed at high temperature, the polycarbosilane can form a SiC layer, the SiC in the precursor liquid is beneficial to the formation of SiC crystals from the polycarbosilane during high-temperature processing, the pyrolytic carbon layer is beneficial to the enhancement of the bonding strength between the SiC layer formed during high-temperature processing and the surface of the guide cone, the SiC layer can improve the oxidation resistance of the surface of the guide cone, enhance the strength of the guide cone, and prevent the surface of the guide cone from being oxidized and damaged during use, thereby avoiding surface cracking and chipping, prolonging the service life of the guide cone, and reducing the influence of the guide cone on the quality of the crystal bar. During high-temperature processing, the oxidation treatment by the oxidizing atmosphere can generate silicon dioxide, which is beneficial to the enhancement of the strength of the coating and the improvement of the oxidation resistance of the coating. DETAILED DESCRIPTION

[0041] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0042] The terms "first", "second", and the like in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those described herein. In addition, "and / or" in the specification and claims indicates at least one of the connected objects, and the character " / ", generally indicates that the front and rear associated objects are in an "or" relationship.

[0043] The processing method of the guide cone provided by the embodiments of the present application will be described in detail below through specific embodiments.

[0044] The processing method of the guide cone of the embodiments of the present application comprises:

[0045] The deposition step: the guide cone is placed in a hydrocarbon gas to deposit a pyrolytic carbon layer;

[0046] The flow guide tube can be prepared from carbon-carbon composite material, and the surface of the flow guide tube can have a carbon layer. The hydrocarbon gas can include at least one of an alkane, an alkene, and an alkyne. For example, the alkane can include at least one of methane, ethane, propane, and cyclopropane; the alkene can include at least one of ethylene, propylene, and butylene; and the alkyne can include at least one of acetylene, propyne, and butyne. The hydrocarbon gas can be mixed with an inert gas, which can include at least one of argon and nitrogen. The flow guide tube can be placed in a mixed gas of the hydrocarbon gas and the inert gas to deposit a pyrolytic carbon layer. The hydrocarbon gas can be diluted by the inert gas. For example, the hydrocarbon gas can be methane, and the inert gas can be nitrogen. The flow guide tube can be placed in a mixed gas of methane and nitrogen, the methane can be diluted by the nitrogen, and the pyrolytic carbon layer can be formed by depositing at 1,000°C and 1 KPa for 4 h. The specific hydrocarbon gas, deposition temperature, and deposition time can be selected as needed.

[0047] The impregnation step includes: placing the flow guide tube with the pyrolytic carbon layer in a precursor liquid for impregnation.

[0048] In the impregnation step, the polycarbosilane, the SiC, and the solvent can be stirred and mixed to form the precursor liquid. The SiC can include at least one of nano-SiC and SiC whiskers. For example, the SiC can be SiC whiskers. The solvent can include at least one of an alkyl alcohol, a hydrocarbon solvent, and a ketone solvent. The alkyl alcohol can include at least one of methanol, ethanol, propanol, butanol, and pentanol. The hydrocarbon solvent can include at least one of n-hexane, benzene, toluene, and xylene. The ketone solvent can include at least one of methanone and acetone. For example, the solvent can be xylene.

[0049] The high-temperature treatment step includes: placing the impregnated flow guide tube in a first atmosphere environment at a first temperature for 1-4 h.

[0050] The flow guide tube treated at the first temperature is placed in a second atmosphere environment at a second temperature for 5-30 min.

[0051] The flow guide tube treated at the second temperature is placed in a third atmosphere environment at a third temperature for 1-4 h.

[0052] The precursor liquid includes polycarbosilane, SiC, and a solvent.

[0053] The first temperature is 120-200°C, and the first atmosphere environment includes an inert atmosphere or a vacuum environment.

[0054] The second temperature is 800-1,200°C, and the second atmosphere environment includes an oxidizing atmosphere.

[0055] The third temperature is 1300-1500℃, and the third atmosphere environment includes an inert atmosphere or a vacuum environment.

[0056] In the high-temperature treatment step, the impregnated flow guide tube is placed in a first atmosphere environment for treatment at a first temperature. The first atmosphere environment can be an inert atmosphere or a vacuum environment, which is beneficial for removing the solvent and light components in the precursor liquid. The flow guide tube treated at the first temperature can be placed in a second atmosphere environment for treatment at a second temperature for 5-30 min. The second atmosphere environment is an oxidizing atmosphere, which can include nitrogen and oxygen. The content of oxygen can be 1-30%, which can be reasonably selected according to actual conditions. The oxidizing atmosphere can be air. The easy-oxidizing components can be removed in advance through the oxidizing atmosphere. The pre-oxidation treatment can generate silicon dioxide, thereby enhancing the strength of the coating and improving the oxidation resistance.

[0057] In the processing method of the flow guide tube in the embodiments of the present application, the flow guide tube is placed in a hydrocarbon gas for deposition to form a pyrolytic carbon layer. After the flow guide tube impregnated with the precursor liquid is subjected to high-temperature treatment, the polycarbosilane can form a SiC layer. The SiC in the precursor liquid is beneficial for the polycarbosilane to form SiC crystals during high-temperature treatment. The pyrolytic carbon layer is beneficial for enhancing the bonding strength between the SiC layer formed during high-temperature treatment and the surface of the flow guide tube. The SiC layer can improve the oxidation resistance of the surface of the flow guide tube, enhance the strength of the flow guide tube, and prevent the surface of the flow guide tube from being oxidized and damaged during use, thereby avoiding surface cracking and chunking, prolonging the service life of the flow guide tube, and reducing the impact of the flow guide tube on the quality of the crystal bar. During high-temperature treatment, the oxidizing treatment using the oxidizing atmosphere can generate silicon dioxide, which is beneficial for enhancing the strength of the coating and improving the oxidation resistance of the coating. The flow guide tube treated by the above method has a SiC ceramic coating generated by pyrolytic carbon and polycarbosilane as a surface layer, which can provide thermal protection and shielding for the internal flow guide tube, can reduce the working temperature of the flow guide tube, and can improve the heat resistance of the flow guide tube. The in-situ grown SiC ceramic crystals can enhance the mechanical properties of the flow guide tube, improve the oxidation resistance and corrosion resistance of the flow guide tube, and prolong the service life. The surface layer is not easy to crack and fall off.

[0058] In some embodiments, the step of placing the flow guide tube in a hydrocarbon gas for deposition to form a pyrolytic carbon layer can include:

[0059] The flow guide cylinder is placed in a hydrocarbon gas to deposit a pyrolytic carbon layer at 900-1300℃ for 2-6h. For example, the flow guide cylinder can be placed in a methane gas to deposit a pyrolytic carbon layer at 900℃, 1000℃ or 1300℃ for 4h, so that a pyrolytic carbon layer is formed on the surface of the flow guide cylinder. The surface of the flow guide cylinder can have a carbon layer, which is conducive to the combination of the pyrolytic carbon layer and the surface of the flow guide cylinder, and improves the bonding strength.

[0060] In some embodiments, the step of placing the flow guide cylinder with the pyrolytic carbon layer in the precursor liquid to perform the impregnation can include:

[0061] The flow guide cylinder with the pyrolytic carbon layer is placed in the precursor liquid to perform the impregnation in a vacuum or an inert environment for 1-4h. For example, the flow guide cylinder with the pyrolytic carbon layer can be placed in the precursor liquid to perform the impregnation in a vacuum for 2h, or the flow guide cylinder with the pyrolytic carbon layer can be placed in the precursor liquid to perform the impregnation in a nitrogen environment for 4h. The mass ratio of polycarbosilane, SiC and solvent in the precursor liquid can be 3:1:5. The impregnation can be performed at room temperature, which can be 20-30℃. During the impregnation, the impregnation can be performed under ultrasonic conditions.

[0062] Optionally, the mass ratio of polycarbosilane, SiC and solvent in the precursor liquid is (1-4):(0.5-1.5):(3-7). For example, the mass ratio of polycarbosilane, SiC and solvent in the precursor liquid can be 3:1:5 or 4:1.5:7. The specific content can be reasonably selected according to the needs.

[0063] Optionally, the precursor liquid can further include a silicate mineral. The silicate mineral can include at least one of mullite and modified mullite. For example, the silicate mineral can be mullite or modified mullite, or the silicate mineral can include mullite and modified mullite. The silicate mineral can enhance the strength of the coating formed on the surface of the flow guide cylinder, facilitate the growth of primary crystals during high-temperature treatment cracking, improve the mechanical properties of the coating, and prevent the coating from falling off.

[0064] Optionally, the precursor liquid can further include a silicate mineral. The silicate mineral can be modified mullite. The mass ratio of modified mullite, polycarbosilane, SiC and solvent in the precursor liquid is (0.5-1.5):(1-4):(0.5-1.5):(3-7). For example, the mass ratio of modified mullite, polycarbosilane, SiC and solvent in the precursor liquid is 1:3:1:5. The specific content can be reasonably selected according to the needs.

[0065] In embodiments of the present application, the preparation method of the modified mullite can include:

[0066] placing the mullite in an inert atmosphere and treating at 700-900℃ for 1-3h;

[0067] cooling the treated mullite, grinding the cooled mullite;

[0068] cleaning the ground mullite;

[0069] stirring and mixing the cleaned mullite with yellow dextrin, drying the stirred and mixed mullite to obtain modified mullite.

[0070] The inert atmosphere can include at least one of argon and nitrogen, for example, the inert atmosphere can be nitrogen. The mullite after high-temperature treatment can be cooled to room temperature, and then ground. The ground mullite can be cleaned, which can be cleaned by ethanol. The cleaned mullite can be stirred and mixed with yellow dextrin, and then dried to obtain modified mullite. The drying can be at 60-120°C. For example, in the preparation process of the modified mullite, the mullite can be placed in an argon atmosphere and treated at 800°C for 2 hours. Then, the treated mullite is cooled, ground, cleaned by ethanol, and then stirred and mixed with yellow dextrin to obtain modified mullite.

[0071] Optionally, the mass ratio of the mullite to the yellow dextrin can be (10-20):(1-4), for example, the mass ratio of the mullite to the yellow dextrin can be 20:2 or 19:1, which can be selected according to actual needs.

[0072] In the embodiments of the present application, the step of placing the impregnated guide cone in a first atmosphere environment and treating at a first temperature for 1-4h can include:

[0073] placing the impregnated guide cone in a first atmosphere environment and heating from room temperature to a first temperature at a first heating rate, and treating at the first temperature for 1-4h;

[0074] The first heating rate can be 3-8°C / min;

[0075] The first temperature can be 120-200°C, the second temperature can be 800-1200°C, the third temperature can be 1300-1500°C, the first atmosphere environment can include an inert atmosphere or a vacuum environment, the second atmosphere environment can include an oxidizing atmosphere, and the oxidizing atmosphere can be air, and the third atmosphere environment can include an inert atmosphere or a vacuum environment. For example, the impregnated guide cone can be placed in an inert atmosphere and heated from room temperature to 150°C at a heating rate of 5°C / min and treated at 150°C for 2h.

[0076] In some embodiments, the step of placing the guide cone treated at the first temperature in a second atmosphere environment and treating at a second temperature for 5-30min can include:

[0077] The flow guide cylinder treated at the first temperature is placed in a second atmosphere environment, heated from the first temperature to a second temperature at a second heating rate, and treated at the second temperature for 5-30 min, the second heating rate being 15-25 °C / min. For example, the flow guide cylinder treated at 150 °C can be placed in air, heated from 150 °C to 1000 °C at a heating rate of 25 °C / min, and treated at 1000 °C for 10 min. The easily oxidizable components can be removed in advance by the oxidizing atmosphere, and the pre-oxidation treatment can generate silicon dioxide, enhance the strength of the coating, and improve the oxidation resistance.

[0078] In some embodiments of the present application, the step of placing the flow guide cylinder treated at the second temperature in a third atmosphere environment, treating at a third temperature for 1-4 h can include:

[0079] The flow guide cylinder treated at the second temperature is placed in a third atmosphere environment, heated from the second temperature to a third temperature at a third heating rate, and treated at the third temperature for 1-4 h, the third heating rate being 3-8 °C / min. For example, the flow guide cylinder treated at 1000 °C can be placed in an inert atmosphere, heated from 1000 °C to 1400 °C at a heating rate of 5 °C / min, and treated at 1400 °C for 1-4 h. The flow guide cylinder is placed in an inert atmosphere and treated at a third temperature, and the polycarbosilane after high-temperature treatment can form a SiC layer, which is beneficial to the formation of SiC crystals from polycarbosilane during high-temperature treatment, and the SiC layer can improve the oxidation resistance of the surface of the flow guide cylinder and enhance the overall strength.

[0080] In some embodiments, the surface of the flow guide cylinder can have a carbon layer. The surface of the flow guide cylinder has a carbon layer, which is beneficial to the bonding of the pyrolytic carbon layer to the surface of the flow guide cylinder and improves the bonding strength.

[0081] In some embodiments, the flow guide cylinder treated by the high-temperature treatment step is repeatedly subjected to the impregnation step and the high-temperature treatment step. For example, the flow guide cylinder treated by the high-temperature treatment step can continue to be subjected to the impregnation step and the high-temperature treatment step to further improve the oxidation resistance and enhance the strength of the coating. For example, the flow guide cylinder treated by the high-temperature treatment step can continue to be subjected to the impregnation step and the high-temperature treatment step, and then be subjected to the impregnation step and the high-temperature treatment step again to enhance the strength of the coating and improve the oxidation resistance.

[0082] Optionally, the hydrocarbon gas includes at least one of methane, ethane, propylene, propane, and cyclopropane. For example, the hydrocarbon gas can be methane, propane, or cyclopropane, and the hydrocarbon gas can be a mixture of methane and propane, and the specific type and content can be selected as needed.

[0083] Optionally, the solvent includes at least one of an alkyl alcohol, a hydrocarbon solvent, and a ketone solvent. The alkyl alcohol can include at least one of methanol, ethanol, propanol, butanol, and pentanol, the hydrocarbon solvent can include at least one of n-hexane, benzene, toluene, and xylene, and the ketone solvent can include at least one of methyl ketone and acetone, such as ethanol, xylene, or acetone, and the specific type and content can be selected according to actual needs.

[0084] The application will be further described below by means of some specific examples.

[0085] Example 1

[0086] The deposition step: the flow guide tube is placed in a methane gas to deposit a pyrolytic carbon layer at 900℃ for 6h;

[0087] The immersion step: the flow guide tube with the pyrolytic carbon layer is placed in a precursor liquid to immerse in a vacuum environment for 1h;

[0088] The high-temperature treatment step: the immersed flow guide tube is placed in an inert atmosphere to treat at a first temperature of 120℃ for 4h;

[0089] The flow guide tube treated at the first temperature of 120℃ is placed in an air atmosphere to treat at a second temperature of 800℃ for 30min;

[0090] The flow guide tube treated at the second temperature of 800℃ is placed in an inert atmosphere to treat at a third temperature of 1300℃ for 4h;

[0091] The precursor liquid includes polycarbosilane, SiC, and a solvent, and the mass ratio of the polycarbosilane, SiC, and the solvent in the precursor liquid is 1:0.5:3.

[0092] Example 2

[0093] The deposition step: the flow guide tube is placed in a methane gas to deposit a pyrolytic carbon layer at 1300℃ for 2h;

[0094] The immersion step: the flow guide tube with the pyrolytic carbon layer is placed in a precursor liquid to immerse in a vacuum environment for 4h;

[0095] The high-temperature treatment step: the immersed flow guide tube is placed in an inert atmosphere to treat at a first temperature of 200℃ for 1h;

[0096] The flow guide tube treated at the first temperature of 200℃ is placed in an oxidizing atmosphere to treat at a second temperature of 1200℃ for 5min;

[0097] The flow guide tube treated at the second temperature of 1200℃ is placed in an inert atmosphere to treat at a third temperature of 1500℃ for 1h;

[0098] The precursor liquid comprises polycarbosilane, SiC and a solvent, and the mass ratio of polycarbosilane, SiC and the solvent in the precursor liquid is 4:1.5:7.

[0099] Example 3

[0100] The deposition step: the flow guide tube is placed in the propane gas to deposit at 1100℃ for 4h to form a pyrolytic carbon layer;

[0101] The impregnation step: the flow guide tube with the pyrolytic carbon layer is placed in the precursor liquid to impregnate in a vacuum environment for 2.5h;

[0102] The high-temperature treatment step: the impregnated flow guide tube is placed in an inert atmosphere to treat at a first temperature of 160℃ for 2.5h;

[0103] The flow guide tube treated at the first temperature of 160℃ is placed in an oxidizing atmosphere to treat at a second temperature of 1000℃ for 10min;

[0104] The flow guide tube treated at the second temperature of 1000℃ is placed in an inert atmosphere to treat at a third temperature of 1400℃ for 2h;

[0105] The precursor liquid comprises polycarbosilane, SiC and a solvent, and the mass ratio of polycarbosilane, SiC and the solvent in the precursor liquid is 3:1:5.

[0106] Example 4

[0107] The deposition step: the flow guide tube is placed in the methane gas to deposit at 1000℃ for 4h to form a pyrolytic carbon layer;

[0108] The impregnation step: the flow guide tube with the pyrolytic carbon layer is placed in the precursor liquid to impregnate in a vacuum environment for 2h;

[0109] The high-temperature treatment step: the impregnated flow guide tube is placed in an inert atmosphere to treat at a first temperature of 150℃ for 2h;

[0110] The flow guide tube treated at the first temperature of 150℃ is placed in an air atmosphere to treat at a second temperature of 1000℃ for 10min;

[0111] The flow guide tube treated at the second temperature of 1000℃ is placed in an inert atmosphere to treat at a third temperature of 1400℃ for 2h;

[0112] The precursor liquid comprises polycarbosilane, SiC and a solvent, and the mass ratio of polycarbosilane, SiC and the solvent in the precursor liquid is 3:1:5.

[0113] Example 5

[0114] The deposition step: the flow guide tube is placed in the methane gas to deposit at 900℃ for 6h to form a pyrolytic carbon layer;

[0115] The impregnation step: the flow guide tube with pyrolytic carbon layer is placed in the precursor liquid to impregnate for 1 hour in a vacuum environment;

[0116] The high-temperature treatment step: the impregnated flow guide tube is placed in an inert atmosphere to be treated at a first temperature of 120 DEG C for 4 hours;

[0117] The flow guide tube treated at the first temperature of 120 DEG C is placed in an air atmosphere to be treated at a second temperature of 800 DEG C for 30 minutes;

[0118] The flow guide tube treated at the second temperature of 800 DEG C is placed in an inert atmosphere to be treated at a third temperature of 1300 DEG C for 4 hours;

[0119] The precursor liquid comprises mullite, polycarbosilane, SiC and solvent, and the mass ratio of mullite, polycarbosilane, SiC and solvent in the precursor liquid is 1.5:1:0.5:3.

[0120] Example 6

[0121] The difference between example 6 and example 5 is that:

[0122] The mass ratio of mullite, polycarbosilane, SiC and solvent in the precursor liquid is 0.5:1:0.5:3.

[0123] Example 7

[0124] The difference between example 6 and example 4 is that:

[0125] The precursor liquid comprises mullite, polycarbosilane, SiC and solvent, and the mass ratio of mullite, polycarbosilane, SiC and solvent in the precursor liquid is 1:3:1:5.

[0126] Example 8

[0127] The difference between example 8 and example 5 is that:

[0128] The precursor liquid comprises modified mullite, polycarbosilane, SiC and solvent, and the mass ratio of modified mullite, polycarbosilane, SiC and solvent in the precursor liquid is 1.5:1:0.5:3.

[0129] The preparation method of the modified mullite is as follows: the mullite is placed in an inert atmosphere to be treated at 700 DEG C for 3 hours, and then cooled, ground and cleaned with anhydrous ethanol; the cleaned mullite is mixed with yellow dextrin by stirring, and then dried to obtain the modified mullite; wherein the mass ratio of mullite to yellow dextrin is 10:4.

[0130] Example 9

[0131] The difference between example 9 and example 8 is that:

[0132] The mass ratio of modified mullite, polycarbosilane, SiC and solvent in the precursor solution is 0.5:1:0.5:3.

[0133] The preparation method of the modified mullite is as follows: the mullite is placed in an inert atmosphere and treated at 900 DEG C for 1 hour, then cooled, ground, washed with anhydrous ethanol, the washed mullite is mixed with yellow dextrin by stirring, and dried to obtain the modified mullite; wherein the mass ratio of the mullite and the yellow dextrin is 10:1.

[0134] Example 10

[0135] The difference between Example 10 and Example 9 is that:

[0136] The mass ratio of the modified mullite and the yellow dextrin is 20:1.

[0137] Example 11

[0138] The difference between Example 11 and Example 4 is that:

[0139] The precursor solution comprises modified mullite, polycarbosilane, SiC and solvent, and the mass ratio of the modified mullite, polycarbosilane, SiC and solvent in the precursor solution is 1:3:1:5.

[0140] The preparation method of the modified mullite is as follows: the mullite is placed in an inert atmosphere and treated at 800 DEG C for 2 hours, then cooled, ground, washed with anhydrous ethanol, the washed mullite is mixed with yellow dextrin by stirring, and dried to obtain the modified mullite; wherein the mass ratio of the mullite and the yellow dextrin is 19:1.

[0141] Example 12

[0142] The deposition step is: the flow guide tube is placed in a methane gas and deposited at 900 DEG C for 6 hours to form a pyrolytic carbon layer;

[0143] The impregnation step is: the flow guide tube with the pyrolytic carbon layer is placed in a precursor solution and impregnated in a vacuum environment for 1 hour;

[0144] The precursor solution comprises modified mullite, polycarbosilane, SiC and solvent, and the mass ratio of the modified mullite, polycarbosilane, SiC and solvent in the precursor solution is 1:3:1:5.

[0145] The preparation method of the modified mullite is as follows: the mullite is placed in an inert atmosphere and treated at 800 DEG C for 2 hours, then cooled, ground, washed with anhydrous ethanol, the washed mullite is mixed with yellow dextrin by stirring, and dried to obtain the modified mullite; wherein the mass ratio of the mullite and the yellow dextrin is 19:1

[0146] The high-temperature treatment step is: placing the impregnated flow cone in an inert atmosphere, increasing the temperature from room temperature to a first temperature of 120 DEG C at a first temperature increasing rate of 3 DEG C / min, and treating at the first temperature of 120 DEG C for 4h;

[0147] The flow cone treated at the first temperature of 120 DEG C is placed in an air atmosphere, increasing the temperature from the first temperature of 120 DEG C to a second temperature of 800 DEG C at a second temperature increasing rate of 25 DEG C / min, and treating at the second temperature of 800 DEG C for 30min;

[0148] The flow cone treated at the second temperature of 800 DEG C is placed in an inert atmosphere, increasing the temperature from the second temperature of 800 DEG C to a third temperature of 1300 DEG C at a third temperature increasing rate of 3 DEG C / min, and treating at the third temperature of 1300 DEG C for 4h.

[0149] Example 13

[0150] The difference between Example 13 and Example 12 is that:

[0151] The first temperature increasing rate is 8 DEG C / min, the second temperature increasing rate is 15 DEG C / min, and the third temperature increasing rate is 8 DEG C / min.

[0152] Example 14

[0153] The deposition step is: placing the flow cone in a methane gas, depositing at 1000 DEG C for 4h to form a pyrolytic carbon layer;

[0154] The impregnation step is: placing the flow cone with the pyrolytic carbon layer in a precursor liquid, and impregnating in a vacuum environment for 2h;

[0155] The precursor liquid comprises modified mullite, polycarbosilane, SiC, and solvent, and the mass ratio of the modified mullite, polycarbosilane, SiC, and solvent in the precursor liquid is 1:3:1:5;

[0156] The preparation method of the modified mullite is: placing mullite in an inert atmosphere, treating at 800 DEG C for 2h, then cooling, grinding, and cleaning with anhydrous ethanol, stirring and mixing the cleaned mullite with yellow dextrin, and drying to obtain the modified mullite; wherein the mass ratio of the mullite to the yellow dextrin is 19:1

[0157] The high-temperature treatment step is: placing the impregnated flow cone in an inert atmosphere, increasing the temperature from room temperature to a first temperature of 150 DEG C at a first temperature increasing rate of 5 DEG C / min, and treating at the first temperature of 150 DEG C for 2h;

[0158] The flow guide tube after the first temperature 150°C treatment is placed in an air atmosphere and heated from the first temperature 150°C to the second temperature 1000°C at a second heating rate of 20°C / min and treated at the second temperature 1000°C for 10 min;

[0159] The flow guide tube after the second temperature 1000°C treatment is placed in an inert atmosphere and heated from the second temperature 1000°C to the third temperature 1400°C at a third heating rate of 5°C / min and treated at the third temperature 1400°C for 2h.

[0160] Example 15

[0161] Example 15 is different from Example 14 in that:

[0162] The flow guide tube after the high temperature treatment step is repeated with the 3 times of the impregnation step and the high temperature treatment step.

[0163] Comparative Example 1

[0164] Untreated flow guide tube.

[0165] Comparative Example 2

[0166] Comparative Example 2 is different from Example 1 in that:

[0167] The deposition step is not performed, the flow guide tube is directly placed in the precursor solution and impregnated in a vacuum environment for 2h, and then the high temperature treatment step is performed.

[0168] Comparative Example 3

[0169] Comparative Example 3 is different from Example 1 in that:

[0170] The air atmosphere is replaced by an inert atmosphere.

[0171] Comparative Example 4

[0172] Comparative Example 4 is different from Example 14 in that:

[0173] The air atmosphere is replaced by an inert atmosphere.

[0174] The flow guide tubes in the above examples and comparative examples are placed in an inert atmosphere at 1400°C for 24 hours, and the changes in the surface of the flow guide tubes are observed, as shown in Table 1.

[0175] Table 1 Changes in flow guide tubes

[0176] Name Morphology change Example 1 No significant change Example 2 No significant change Example 3 No significant change Example 4 No significant change Example 5 No significant change Example 6 No significant change Example 7 No significant change Example 8 No significant change Example 9 No significant change Example 10 No significant change Example 11 No significant change Example 12 No significant change Example 13 No significant change Example 14 No significant change Example 15 No significant change Comparative Example 1 Surface uneven, substrate deformed, overall grayish Comparative Example 2 Coating partially detached Comparative Example 3 Coating surface slightly cracked Comparative Example 4 Coating surface slightly cracked, with bubbles

[0177] From Table 1, the surface of the flow guiding tubes in Examples 1-15 has no obvious change, and the surface of the flow guiding tubes in Comparative Examples 1-4 has different damages or changes. It can be seen that the surface coating structure of the flow guiding tube treated by the method of the present application is stable, the surface of the flow guiding tube is not easy to be oxidized or damaged during high temperature use, and the surface cracking, falling off and the like do not occur, so that the use time of the flow guiding tube can be prolonged.

[0178] The above describes the embodiments of the present application, but the present application is not limited to the above specific embodiments, and the above specific embodiments are only illustrative but not restrictive. Those skilled in the art can make many forms under the inspiration of the present application without departing from the purpose of the present application and the scope protected by the claims, which all belong to the protection of the present application.

Claims

1. A method of treating a flow tube, characterized by, The method comprises the following steps: a deposition step of placing the flow guide cylinder in a hydrocarbon gas to deposit a pyrolytic carbon layer; an impregnation step of placing the flow guide cylinder with the pyrolytic carbon layer in a precursor liquid to impregnate; a high-temperature treatment step of placing the impregnated flow guide cylinder in a first atmosphere at a first temperature for 1-4 hours; placing the flow guide cylinder treated at the first temperature in a second atmosphere at a second temperature for 5-30 minutes; placing the flow guide cylinder treated at the second temperature in a third atmosphere at a third temperature for 1-4 hours; wherein the precursor liquid comprises polycarbosilane, SiC, and a solvent; the first temperature is 120-200℃, and the first atmosphere is an inert atmosphere or a vacuum environment; the second temperature is 800-1200℃, and the second atmosphere is an oxidizing atmosphere; the third temperature is 1300-1500℃, and the third atmosphere is an inert atmosphere or a vacuum environment; the mass ratio of polycarbosilane, SiC, and the solvent in the precursor liquid is (1-4):(0.5-1.5):(3-7).

2. The treatment method according to claim 1, characterized in that, The step of placing the flow guide cylinder in a hydrocarbon gas to deposit a pyrolytic carbon layer comprises: placing the flow guide cylinder in a hydrocarbon gas at 900-1300℃ to deposit a pyrolytic carbon layer for 2-6 hours.

3. The treatment method of claim 1, wherein The step of placing the flow guide cylinder with the pyrolytic carbon layer in a precursor liquid to impregnate comprises: placing the flow guide cylinder with the pyrolytic carbon layer in a precursor liquid to impregnate in a vacuum or an inert environment for 1-4 hours.

4. The treatment method of claim 1, wherein The precursor liquid further comprises a silicate mineral, and the silicate mineral comprises at least one of mullite and modified mullite.

5. The treatment method according to claim 4, characterized in that, The precursor liquid further comprises a silicate mineral, and the silicate mineral is modified mullite, and the mass ratio of modified mullite, polycarbosilane, SiC, and the solvent in the precursor liquid is (0.5-1.5):(1-4):(0.5-1.5):(3-7).

6. The treatment method according to claim 4 or 5, characterized in that, The preparation method of the modified mullite comprises: placing the mullite in an inert atmosphere at 700-900℃ for 1-3 hours; cooling and grinding the treated mullite; cleaning the ground mullite; stirring and mixing the cleaned mullite with yellow metaplexin, drying to obtain the modified mullite.

7. The treatment method according to claim 6, characterized in that, The mass ratio of mullite to yellow metaplexin is (10-20):(1-4).

8. The treatment method of claim 1, wherein The step of placing the impregnated flow guide cylinder in a first atmosphere at a first temperature for 1-4 hours comprises: placing the impregnated flow guide cylinder in a first atmosphere, heating from room temperature to the first temperature at a first heating rate, and treating at the first temperature for 1-4 hours; the first heating rate is 3-8℃ / min; and / or The step of placing the flow guide cylinder treated at the first temperature in a second atmosphere at a second temperature for 5-30 minutes comprises: placing the flow guide cylinder treated at the first temperature in a second atmosphere, heating from the first temperature to the second temperature at a second heating rate, and treating at the second temperature for 5-30 minutes; the second heating rate is 15-25℃ / min; and / or The step of placing the guide tube treated at the second temperature in a third atmosphere and treating it at the third temperature for 1-4 hours comprises: placing the guide tube treated at the second temperature in a third atmosphere, heating the temperature from the second temperature to a third temperature at a third heating rate, and treating the guide tube at the third temperature for 1-4 hours; The third heating rate is 3-8°C / min.

9. The processing method according to claim 1, wherein Repeating the impregnation step and the high temperature treatment step on the draft tube after the high temperature treatment step; and / or The hydrocarbon gas includes at least one of methane, ethane, propylene, propane, and cyclopropane; and / or The solvent includes at least one of a hydrocarbon solvent and a ketone solvent.