阅读说明：本技术 一种用于增强石墨制品抗氧化涂层的制备方法 (Preparation method of anti-oxidation coating for reinforcing graphite product ) 是由 欧明桥 于 2020-11-17 设计创作，主要内容包括：本发明涉及抗氧化石墨材料涂层加工方法技术领域,具体为一种用于增强石墨制品抗氧化涂层的制备方法,其包括以下步骤：粉料称取→石墨化罐装入→密封→反应→鼓风排气→涂层→平台下降→抬升→复位输出,通过反应步骤中的单质硅粉末与氧化铝粉末通过反应形成一氧化硅气体,并利用鼓风排气步骤中,搅拌桨叶将一氧化硅气体输送至涂层平台对平台上的石墨工件进行涂层,形成碳化硅涂层,配合平台下降步骤,使石墨工件在整个反应过程中,进行移动,使气体形成流动,氧化硅气体能始终围绕石墨工件进行反应,解决了现有石墨工件涂层不均匀的技术问题。(The invention relates to the technical field of processing methods of anti-oxidation graphite material coatings, in particular to a preparation method of an anti-oxidation coating for a reinforced graphite product, which comprises the following steps: powder is weighed → graphitizing jar is packed → is sealed → reaction → air blast exhaust → coating → platform descends → lifting → reset output, form silicon monoxide gas through the reaction of simple substance silicon powder in the reaction step with alumina powder, and utilize in the air blast exhaust step, stirring paddle carries silicon monoxide gas to the coating platform and coats the graphite work piece on the platform, form the carborundum coating, cooperation platform descends the step, make the graphite work piece in whole reaction process, remove, make gaseous formation flow, silicon oxide gas can react around the graphite work piece all the time, the inhomogeneous technical problem of current graphite work piece coating has been solved.)

1. A preparation method for enhancing an oxidation resistant coating of a graphite product is characterized by comprising the following steps:

firstly, weighing powder, calculating and weighing Si and Al according to the coating area of the graphite workpiece (10)₂O₃The powder is fully mixed, and the mixed powder is placed in a cavity (21) in the graphitizing tank (2);

step two, loading a graphitizing tank, opening a cabin door (12) on a reaction kettle (1), transferring the graphitizing tank (2) added with powder into the reaction kettle (1), enabling a rotating shaft (311) of a stirring blade (31) on a stirring mechanism (3) at the bottom of the graphitizing tank (2) to be in inserted butt joint with a butt joint shaft (321) on a rotating disk (32) at the bottom of the reaction kettle (1), and closing the cabin door (12);

thirdly, sealing, namely after a graphite workpiece (10) to be coated is placed on the coating platform (4), descending a hatch cover (11) at the top of the reaction kettle (1), driving the graphite workpiece (10) to enter the reaction kettle (1), sealing the reaction kettle (1), synchronously descending a sealing cover (51) connected with the hatch cover (11), and sealing the top of the graphitization tank (2);

step four, reacting, namely heating the inside of the reaction kettle (1) by a heater on the inner wall of the reaction kettle (1), introducing Ar gas into the reaction kettle (1) through a gas transmission pipeline (13), and introducing Si and Al in the graphitization tank (2) synchronously₂O₃The powder reacts under the stirring of the stirring blade (31) driven by the driving component (61) to generate Si0 gas;

fifthly, blowing air and exhausting air, wherein a lifting part (6211) on a lifting ring (621) which rotates synchronously with a stirring blade (31) is abutted against a transmission shaft (622) in a linkage assembly (62), so that the linkage assembly (62) is in transmission connection with a driving assembly (61), an exhaust valve (53) in an exhaust mechanism (5) for connecting the graphitization tank (2) and the coating platform (4) is started, and Si0 gas in the graphitization tank (2) is conveyed to the graphite workpiece (10) through an exhaust pipe (521) in the exhaust mechanism (5) under the rotation of the stirring blade (31);

sixthly, coating, namely reacting Si0 gas discharged to the graphite workpiece (10) with the surface layer of the graphite workpiece (10) to form a SiC coating to wrap the graphite workpiece (10), and forming CO waste gas;

step seven, the platform descends, and in synchronization with the step four, the driving assembly (61) drives the lifting assembly (41) for driving the coating platform (4) to lift through the linkage assembly (62), the coating platform (4) gradually approaches to the graphitizing tank (2), and the graphite workpiece (10) is driven to be separated from the package of the CO waste gas;

eighthly, lifting, wherein in the process that the coating platform (4) approaches the graphitizing tank (2), a lifting assembly (44) on the coating platform (4) is started, a lifting rod (441) in the lifting assembly (44) is abutted against the sealing cover (51), the lifting rod (441) drives a lifting arm (444) to lift, so that the graphite workpiece (10) is lifted, and the bottom surface of the graphite workpiece (10) is exposed for coating; and

and step nine, resetting and outputting, wherein after the graphite workpiece (10) finishes coating, the driving assembly (61) reverses, the coating platform (4) is lifted and reset through the linkage assembly (62), and after the reaction kettle (1) is cooled to natural temperature, the graphite workpiece (10) is output.

2. The method for preparing the anti-oxidation coating for the reinforced graphite product as claimed in claim 1, wherein in the second step, the cross-shaped slot (312) on the rotating shaft (311) is inserted and butted with the quincunx head (322) on the butting shaft (321), so that the stirring blade (31) rotates along with the rotating disc (32).

3. The preparation method of the oxidation-resistant coating for the reinforced graphite product according to claim 1, wherein in the third step, a material rack (42) for supporting the graphite workpiece (10) is arranged at the position of the center line of the coating platform (4), the material rack (42) is provided with a hollow hole (421), and a plurality of air holes (43) are uniformly distributed at the position of the coating platform (4) opposite to the material rack (42).

4. The method for preparing the anti-oxidation coating for the reinforced graphite product as claimed in claim 1, wherein in the fifth step, the exhaust pipe (521) is provided with an exhaust hood (522) covering the graphite workpiece (10) on the top, and the exhaust pipe (521) comprises a steel pipe part (5211) and a hose part (5212).

5. The method for preparing the antioxidant coating for the reinforced graphite product according to claim 4, wherein an exhaust valve (53) is disposed at a connection position of the steel pipe portion (5211) and the hose portion (5212), the exhaust valve (53) is rotatably sleeved on the steel pipe portion (5211), a valve closing plate (531) is disposed in the exhaust valve (53), a valve compensation closing plate (532) matched with the valve closing plate (531) is disposed on the steel pipe portion (5211), initially, the valve closing plate (531) is combined with the valve compensation closing plate (532) to seal the exhaust pipe (521), when the driving assembly (61) drives the exhaust valve (53) to rotate through the linkage assembly (62), the valve closing plate (531) is staggered with the valve compensation closing plate (532), and the exhaust pipe (521) is communicated.

6. The method for preparing an oxidation-resistant coating for reinforced graphite products according to claim 1, wherein in the fifth step, the lifting assembly (41) comprises:

an outer gear ring (411), the outer gear ring (411) is rotatably mounted on the hatch (11) and is driven to rotate by the driving assembly (61) through the linkage assembly (62);

a plurality of rotating gears (412), a plurality of rotating gears (412) are arranged in the outer gear ring (411) at equal intervals along the circumferential circumference of the outer gear ring (411), and are meshed with internal teeth (413) on the outer gear ring (411);

the screw rods (414) are arranged in one-to-one correspondence with the rotary gears (412), the tops of the screw rods (414) are rotatably mounted on the hatch cover (11), and the bottoms of the screw rods (414) are rotatably mounted on the sealing cover (51); and

the lead screw nut (415) is sleeved on the corresponding lead screw (414) and is arranged on the coating platform (4), and the lead screw (414) rotates to drive the coating platform (4) to move through the lead screw nut (415).

7. The method for preparing the anti-oxidation coating for the reinforced graphite product as claimed in claim 6, wherein the internal teeth (413) on the external gear ring (411) are arranged in a missing tooth mode, the internal teeth (413) are divided into a plurality of tooth parts (4131) which are arranged at equal intervals along the circumferential direction of the external gear ring (411), when the tooth parts (4131) are matched with the rotating gear (412), the coating platform (4) descends, and when the vacant positions on the internal teeth (413) are matched with the rotating gear (412), the coating platform (4) stops descending.

8. The method for preparing an oxidation-resistant coating for reinforced graphite articles according to claim 6, wherein in the fifth step, the driving assembly (61) comprises:

the motor (611), the motor (611) is installed at the bottom of the reaction kettle (1);

a main shaft (612), wherein the main shaft (612) is vertically arranged in the reaction kettle (1) and is driven by the motor (611) to rotate; and

a drive sprocket set (613), the drive sprocket set (613) being mounted between the spindle (612) and the rotary disk (32), which drives the rotary disk (32) to rotate with the spindle (612).

9. The method for preparing an oxidation-resistant coating for reinforcing graphite articles according to claim 8, wherein in the fifth step, the linkage assembly (62) comprises:

a lift ring (621), the lift ring (621) being disposed along a circumferential direction of the rotating disk (32), and including a convex lift portion (6211) and a concave settling portion (6212);

the transmission shaft (622) is vertically and rotatably arranged on the hatch cover (11), can be adjusted in a lifting manner along the axial direction, and is arranged on the lifting ring (621) in a sliding and abutting manner at the bottom of the transmission shaft (622);

a driving gear (623), wherein the driving gear (623) is installed at the top of the main shaft (612);

the transmission gear (624) is mounted at the top of the transmission shaft (622), and when the transmission shaft (622) collides with the lifting part (6211), the transmission gear (624) is meshed with the driving gear (623) and the external teeth (4112) on the external gear ring (411) respectively; and

the transmission chain wheel (625) is rotatably arranged in the middle of the transmission shaft (622) and is arranged statically relative to the transmission shaft (622) in the vertical direction, and when the transmission shaft (622) is lifted, a key (6221) on the transmission chain wheel is inserted and matched with a key groove (6251) on the transmission chain wheel (625);

the rotating chain wheel (626) is sleeved on the exhaust valve (53), and the rotating chain wheel (626) is connected with the transmission chain wheel (625) through a transmission chain (627).

Technical Field

The invention relates to the technical field of an anti-oxidation graphite material coating method, in particular to a preparation method of an anti-oxidation coating for a reinforced graphite product.

Background

The graphite material is a basic material with various excellent characteristics, and particularly, the graphite material can still ensure the sufficient product performance under the high temperature condition of more than 1200 ℃, which cannot be realized by common metal materials. However, the graphite material has a biggest defect that the graphite material cannot realize the above functions due to oxidation in an oxygen-containing environment, and therefore, the graphite material is subjected to surface modification based on a coating technology, so that the graphite material can normally exert excellent characteristics in the oxygen-containing environment.

The mainstream graphite surface modification technology at present is CVD (chemical vapor deposition) coating method, and a compact independent coating structure can be generated on the graphite surface by the method, so that the graphite material is isolated from the external oxygen-containing environment, and the graphite material is protected.

The problems and the defects of the existing coating technology are mainly that the coating of the graphite material is prepared by the CVD technology, the technological process is complex, the cost of raw materials is high, the graphite coating structure with higher uniformity can be obtained, but the comprehensive cost is higher, the cost performance is insufficient in the application environment of the middle-end and low-end antioxidant graphite materials, and the coating is difficult to be widely applied.

In chinese patent with patent application No. CN201210374319.1, a method for preparing a silicon carbide coating on a graphite surface is disclosed, which comprises: placing a graphite crucible filled with solid silicon materials in a high-temperature graphitization furnace, placing a graphite matrix on a graphite support in the graphite crucible, and utilizing direct reaction of silicon vapor and carbon on the surface of the graphite matrix to generate a silicon carbide coating; and secondly, placing the graphite substrate with the silicon carbide coating on the surface in a chemical vapor deposition furnace, and cracking the surface of the silicon carbide coating on the surface of the graphite substrate to generate a CVD (chemical vapor deposition) silicon carbide coating.

Although the technical scheme disclosed in the above patent solves the problem that silicon vapor is used to form an anti-oxidation silicon carbide coating on the surface of a graphite workpiece, the technical scheme uses a silicon simple substance which can be prepared only by processing silicate or silicon dioxide, the comprehensive cost is high, in the reaction process of the silicon vapor and the graphite workpiece, the silicon vapor does not circulate, the silicon vapor is difficult to uniformly wrap the graphite workpiece, and the prepared coating is uneven in thickness.

Disclosure of Invention

Aiming at the problems, the invention provides a preparation method for enhancing an oxidation-resistant coating of a graphite product, which comprises the steps of reacting elemental silicon powder and alumina powder in a reaction step to form silicon monoxide gas, conveying the silicon monoxide gas to a coating platform by using stirring blades in an air blowing and exhausting step to coat a graphite workpiece on the platform to form a silicon carbide coating, and matching with a platform descending step to move the graphite workpiece in the whole reaction process to enable the gas to flow, so that the silicon monoxide gas can always react around the graphite workpiece, and the technical problem of uneven coating of the existing graphite workpiece is solved.

In order to achieve the purpose, the invention provides the following technical scheme:

a preparation method for enhancing an oxidation resistant coating of a graphite product comprises the following steps:

step one, powder weighing, namely calculating and weighing Si and Al according to the coating area of the graphite workpiece₂O₃The powder is fully mixed, and the mixed powder is placed in a cavity in the graphitizing tank;

step two, loading a graphitizing tank, opening a cabin door on the reaction kettle, transferring the graphitizing tank added with the powder into the reaction kettle, enabling a rotating shaft of a stirring blade on a stirring mechanism at the bottom of the graphitizing tank to be in inserted butt joint with a butt joint shaft on a rotating disk arranged at the bottom of the reaction kettle, and closing the cabin door;

sealing, namely after a graphite workpiece to be coated is placed on a coating platform, descending a hatch cover at the top of the reaction kettle, driving the graphite workpiece to enter the reaction kettle, sealing the reaction kettle, synchronously descending a sealing cover connected with the hatch cover, and sealing the top of the graphitization tank;

step four, reacting, namely heating the inside of the reaction kettle by a heater on the inner wall of the reaction kettle, synchronously introducing Ar gas into the reaction kettle through a gas transmission pipeline on the reaction kettle, and introducing Si and Al in the graphitization tank₂O₃The powder reacts under the stirring of the stirring paddle blade driven by the driving component to generate Si0 gas;

step five, blowing air and exhausting, wherein a lifting part on a lifting ring which synchronously rotates along with a stirring blade is abutted against a transmission shaft in a linkage assembly, so that the linkage assembly is in transmission connection with a driving assembly and is used for connecting the graphitization tank with an exhaust valve in an exhaust mechanism of the coating platform to be started, and Si0 gas in the graphitization tank is conveyed to the graphite workpiece through an exhaust pipe in the exhaust mechanism under the rotation of the stirring blade;

sixthly, coating, namely reacting Si0 gas discharged to the graphite workpiece with the surface layer of the graphite workpiece to form a SiC coating to wrap the graphite workpiece and simultaneously form CO waste gas;

step seven, the platform descends, and in synchronization with the step four, the driving assembly drives the lifting assembly driving the coating platform to ascend and descend through the linkage assembly, the coating platform gradually approaches the graphitizing tank, and the graphite workpiece is driven to be separated from the package of the CO waste gas;

step eight, lifting, wherein in the process that the coating platform approaches the graphitizing tank, a lifting assembly on the coating platform is started, a lifting rod in the lifting assembly is abutted to the sealing cover, and the lifting rod drives a lifting arm to lift, so that the graphite workpiece is lifted, the bottom surface of the graphite workpiece is exposed, and coating is performed; and

and step nine, resetting and outputting, wherein after the graphite workpiece is coated, the driving assembly rotates reversely, the coating platform is lifted and reset through the linkage assembly, and after the reaction kettle is cooled to the natural temperature, the graphite workpiece is output.

In the second step, the cross-shaped groove on the rotating shaft is inserted into and butted with the quincuncial head on the butting shaft, so that the stirring blade rotates along with the rotating disc.

As an improvement, in the third step, a material rest for supporting the graphite workpiece is arranged at the central line position of the coating platform, a hollow hole is formed in the material rest, and a plurality of air holes are uniformly distributed at the position, opposite to the material rest, of the coating platform.

In the fifth step, an exhaust hood covering the graphite workpiece is arranged at the top of the exhaust pipe, and the exhaust pipe comprises a steel pipe part and a hose part.

As an improvement, the steel pipe portion with the hookup location department of hose portion is provided with the air discharge valve, and this air discharge valve rotates the cover and locates on the steel pipe portion, be provided with the valve shrouding in it, be provided with this valve shrouding complex valve compensation shrouding on the steel pipe portion, during the beginning, the valve shrouding with the combination of valve compensation shrouding is sealed the blast pipe, drive assembly passes through the linkage assembly drives when the air discharge valve is rotatory, the valve shrouding with the valve compensation shrouding staggers, the blast pipe link up.

As an improvement, in the fifth step, the lifting assembly includes:

the outer gear ring is rotatably mounted on the cabin cover and is driven to rotate by the driving assembly through the linkage assembly;

the rotary gears are arranged in the outer gear ring at equal intervals along the circumferential circumference of the outer gear ring and are meshed with the inner teeth on the outer gear ring;

the screw rods are arranged in one-to-one correspondence with the rotary gears, the tops of the screw rods are rotatably installed on the cabin cover, and the bottoms of the screw rods are rotatably installed on the sealing cover; and

the lead screw nut is sleeved on the corresponding lead screw and is arranged on the coating platform, and the lead screw rotates to drive the coating platform to move through the lead screw nut.

As an improvement, the internal tooth on the outer ring gear is the scarce tooth setting, and this internal tooth is followed the tooth portion that a plurality of equidistance set up is separated into to the circumference of outer ring gear, tooth portion with when the rotating gear cooperatees, the coating platform descends, vacant position on the internal tooth with when the rotating gear cooperatees, the coating platform stops descending.

As an improvement, in the fifth step, the driving assembly includes:

the motor is arranged at the bottom of the reaction kettle;

the main shaft is vertically arranged in the reaction kettle and is driven to rotate by the motor; and

the driving chain wheel set is installed between the main shaft and the rotating disc and drives the rotating disc to rotate along with the main shaft.

As an improvement, in the fifth step, the linkage assembly includes:

the lifting ring is arranged along the circumferential direction of the rotating disc and comprises a convex lifting part and a concave settling part;

the transmission shaft is vertically and rotatably arranged on the cabin cover, can be adjusted in a lifting manner along the axial direction, and is arranged on the lifting ring in a sliding and abutting mode at the bottom of the transmission shaft;

the driving gear is mounted at the top of the main shaft;

the transmission gear is arranged at the top of the transmission shaft, and when the transmission shaft is abutted against the lifting part, the transmission gear is respectively meshed with the driving gear and the external teeth on the external gear ring; and

the transmission chain wheel is rotatably arranged in the middle of the transmission shaft and is arranged in a static manner in the vertical direction relative to the transmission shaft, and when the transmission shaft is lifted, keys on the transmission chain wheel are in inserting fit with key grooves on the transmission chain wheel;

and the rotating chain wheel is sleeved on the exhaust valve and is connected with the transmission chain wheel through a transmission chain.

The invention has the beneficial effects that:

(1) according to the method, elemental silicon powder and silicon dioxide powder in the reaction step react to form silicon oxide gas, in the blast air exhaust step, the stirring paddle is used for conveying the silicon oxide gas to the coating platform to coat the graphite workpiece on the platform to form a silicon carbide coating, and the platform descending step is matched to move the graphite workpiece in the whole reaction process so that the gas flows, so that the silicon oxide gas can always react around the graphite workpiece to realize uniform coating of the graphite workpiece;

(2) in the coating step, the silicon oxide gas is used for reacting with the graphite workpiece to generate a silicon carbide coating and carbon monoxide gas, and the carbon monoxide gas can be recycled to the next graphite workpiece to be coated and processed for carrying out reduction pretreatment on the graphite workpiece to be coated and processed, so that residual oxides in pores of the graphite workpiece are removed, and the stability in the coating process is ensured;

(3) according to the invention, the stirring blades are used for promoting the reaction speed of the simple substance silicon powder and the silicon dioxide powder in the reaction step and the air blowing and exhausting step respectively, and the silicon oxide gas generated by the reaction can be rapidly exhausted in the air blowing and exhausting step, so that the interference of the air pressure of Ar gas is avoided, and the purpose of uniformly coating the graphite workpiece is achieved;

(4) in the platform descending step, the coating platform bearing the graphite workpiece moves downwards after reacting with the silicon oxide gas for a certain time, so that the carbon monoxide gas generated by the reaction can not wrap the graphite workpiece, the subsequent silicon oxide gas can smoothly contact with the surface of the graphite workpiece, and the interference and influence of the carbon monoxide gas on the coating are avoided;

(5) in the lifting step, the lifting rod in the lifting assembly is abutted against the sealing cover at the top of the graphitizing tank, so that the lifting arm drives the graphitizing workpiece arranged on the coating platform to lift the graphitizing workpiece to separate from the coating platform, expose the ground and perform coating reaction with silicon oxide gas, and ensure that each part of the graphite workpiece is subjected to coating reaction.

In conclusion, the method has the advantages of uniform coating, full reaction, low comprehensive cost and the like, and is particularly suitable for the technical field of the coating method of the antioxidant graphite material.

Drawings

FIG. 1 is a schematic flow chart of the preparation method of the present invention;

FIG. 2 is a schematic perspective view of the present invention;

FIG. 3 is a schematic view of the internal structure of a reaction vessel according to the present invention;

FIG. 4 is a schematic cross-sectional view of the present invention;

FIG. 5 is a schematic diagram of the side view of the inside of the reaction vessel according to the present invention;

FIG. 6 is a schematic perspective view of a graphitization pot according to the present invention;

FIG. 7 is a schematic perspective view of a stirring blade according to the present invention;

FIG. 8 is a perspective view of a rotary plate according to the present invention;

FIG. 9 is an enlarged view of the structure at A in FIG. 8;

FIG. 10 is a schematic view of the transmission shaft and the transmission gear of the present invention;

FIG. 11 is a perspective view of the outer ring gear of the present invention;

FIG. 12 is a schematic cross-sectional view of an exhaust pipe according to the present invention;

FIG. 13 is a perspective view of the exhaust valve of the present invention;

figure 14 is a perspective view of the lift assembly of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like, indicate orientations and positional relationships based on those shown in the drawings, and are used only for convenience of description and simplicity of description, and do not indicate or imply that the equipment or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be considered as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

The first embodiment is as follows:

as shown in fig. 1, a method for preparing an oxidation-resistant coating for a reinforced graphite product comprises the following steps:

firstly, weighing powder, namely calculating and weighing Si and Al according to the coating area of the graphite workpiece 10₂O₃The powder is fully mixed, and the mixed powder is placed in the cavity 21 in the graphitizing tank 2;

step two, loading a graphitizing tank, opening a hatch door 12 on a reaction kettle 1, transferring the graphitizing tank 2 added with powder into the reaction kettle 1, enabling a rotating shaft 311 of a stirring blade 31 on a stirring mechanism 3 at the bottom of the graphitizing tank 2 to be in inserted butt joint with a butt joint shaft 321 on a rotating disc 32 arranged at the bottom of the reaction kettle 1, and closing the hatch door 12;

sealing, namely after placing the graphite workpiece 10 to be coated on the coating platform 4, descending the hatch 11 at the top of the reaction kettle 1 to drive the graphite workpiece 10 to enter the reaction kettle 1, sealing the reaction kettle 1, synchronously descending the seal cover 51 connected with the hatch 11, and sealing the top of the graphitization tank 2;

step four, reacting, namely heating the reaction kettle 1 by a heater on the inner wall of the reaction kettle 1, synchronously introducing Ar gas into the reaction kettle 1 through a gas transmission pipeline 13 on the reaction kettle 1, and introducing Si and Al in the graphitization tank 2₂O₃The powder reacts under the stirring of the stirring paddle 31 driven by the driving component 61 to generate Si0 gas;

step five, blowing air and exhausting air, wherein a lifting part 6211 on a lifting ring 621 synchronously rotating along with the stirring blade 31 is abutted against a transmission shaft 622 in a linkage assembly 62, so that the linkage assembly 62 is in transmission connection with a driving assembly 61 and is used for connecting the graphitization tank 2 with an exhaust valve 53 in an exhaust mechanism 5 of the coating platform 4 to be started, and under the rotation of the stirring blade 31, Si0 gas in the graphitization tank 2 is conveyed to the graphite workpiece 10 through an exhaust pipe 521 in the exhaust mechanism 5;

sixthly, coating, namely reacting Si0 gas discharged to the graphite workpiece 10 with the surface layer of the graphite workpiece 10 to form a SiC coating to wrap the graphite workpiece 10 and simultaneously form CO waste gas;

step seven, the platform descends, and in synchronization with the step four, the driving assembly 61 drives the lifting assembly 41 for driving the coating platform 4 to ascend and descend through the linkage assembly 62, and the coating platform 4 gradually approaches the graphitizing tank 2 to drive the graphite workpiece 10 to be separated from the package of the CO waste gas;

eighthly, lifting, wherein in the process that the coating platform 4 approaches the graphitizing tank 2, a lifting assembly 44 on the coating platform 4 is started, a lifting rod 441 in the lifting assembly 44 is abutted to the seal cover 51, and the lifting rod 441 drives a lifting arm 444 to lift, so that the graphite workpiece 10 is lifted, and the bottom surface of the graphite workpiece 10 is exposed for coating; and

and step nine, resetting and outputting, wherein after the graphite workpiece 10 finishes coating, the driving assembly 61 rotates reversely, the coating platform 4 is lifted and reset through the linkage assembly 62, and after the reaction kettle 1 is cooled to the natural temperature, the graphite workpiece 10 is output.

In the second step, the cross-shaped groove 312 of the rotating shaft 311 and the quincunx head 322 of the abutting shaft 321 are inserted and abutted, so that the stirring blade 31 rotates along with the rotating disk 32, and the stirring blade 31 is located.

Further, in the third step, a material rest 42 for supporting the graphite workpiece 10 is arranged at the central line position of the coating platform 4, a hollow hole 421 is formed in the material rest 42, and a plurality of air holes 43 are uniformly distributed at the position of the coating platform 4, which is opposite to the material rest 42.

Further, in the fifth step, an exhaust hood 522 covering the graphite workpiece 10 is provided on the top of the exhaust pipe 521, and the exhaust pipe 521 includes a steel pipe portion 5211 and a hose portion 5212.

In addition, the connection position between the steel pipe portion 5211 and the hose portion 5212 is provided with an exhaust valve 53, the exhaust valve 53 is rotatably sleeved on the steel pipe portion 5211, a valve seal plate 531 is arranged in the exhaust valve portion 5211, a valve compensation seal plate 532 matching with the valve seal plate 531 is arranged on the steel pipe portion 5211, initially, the valve seal plate 531 and the valve compensation seal plate 532 are combined to seal the exhaust pipe 521, when the driving assembly 61 drives the exhaust valve 53 to rotate through the linkage assembly 62, the valve seal plate 531 and the valve compensation seal plate 532 are staggered, and the exhaust pipe 521 penetrates through the exhaust pipe.

It should be noted that, in the fifth step, the lifting assembly 41 includes:

an outer gear ring 411, wherein the outer gear ring 411 is rotatably mounted on the hatch 11 and is driven to rotate by the driving assembly 61 through the linkage assembly 62;

a plurality of rotary gears 412, which are arranged inside the outer ring gear 411 at equal intervals along the circumferential circumference of the outer ring gear 411 and are meshed with the internal teeth 413 on the outer ring gear 411;

the screw rods 414 are arranged in one-to-one correspondence with the rotary gears 412, the tops of the screw rods 414 are rotatably mounted on the hatch cover 11, and the bottoms of the screw rods 414 are rotatably mounted on the cover 51; and

the lead screw nut 415 is sleeved on the corresponding lead screw 414 and is installed on the coating platform 4, and the lead screw 414 rotates to drive the coating platform 4 to move through the lead screw nut 415.

Preferably, the internal teeth 413 of the external gear ring 411 are arranged in a missing tooth manner, the internal teeth 413 are divided into a plurality of tooth portions 4131 which are arranged at equal intervals along the circumferential direction of the external gear ring 411, when the tooth portions 4131 are matched with the rotating gear 412, the coating platform 4 descends, and when the vacant positions on the internal teeth 413 are matched with the rotating gear 412, the coating platform 4 stops descending.

In the fifth step, the driving assembly 61 includes:

the motor 611, the said motor 611 is mounted to the bottom of the said reaction vessel 1;

a main shaft 612, wherein the main shaft 612 is vertically installed in the reaction kettle 1 and is driven by the motor 611 to rotate; and

a set of drive sprockets 613, the set of drive sprockets 613 being mounted between the main shaft 612 and the rotating disk 32, which drive the rotating disk 32 to rotate with the main shaft 612.

Further, in the fifth step, the linkage assembly 62 includes:

a lifting ring 621, which is provided along the circumferential direction of the rotating disk 32, and includes a convex lifting portion 6211 and a concave settling portion 6212;

the transmission shaft 622 is vertically and rotatably mounted on the hatch 11, can be adjusted in an up-and-down manner along the axial direction, and is slidably arranged on the lifting ring 621 in an abutting manner at the bottom of the transmission shaft 622;

a driving gear 623, wherein the driving gear 623 is mounted at the top of the main shaft 612;

a transmission gear 624, wherein the transmission gear 624 is installed on the top of the transmission shaft 622, and when the transmission shaft 622 collides with the lifting part 6211, the transmission gear 624 is meshed with the driving gear 623 and the external teeth 4112 on the external gear ring 411 respectively; and

the transmission chain wheel 625 is rotatably mounted in the middle of the transmission shaft 622 and is arranged statically in the vertical direction relative to the transmission shaft 622, and when the transmission shaft 622 is lifted, a key 6221 on the transmission chain wheel 625 is inserted and matched with a key groove 6251 on the transmission chain wheel 625;

the rotating chain wheel 626 is sleeved on the exhaust valve 53, and is connected with the transmission chain wheel 625 through a transmission chain 627.

Example two:

as shown in fig. 2 to 8, a manufacturing apparatus for a SiC coating for enhancing oxidation resistance of a graphite material includes:

the reactor comprises a reaction kettle 1, wherein a lifting hatch 11 is arranged at the top of the reaction kettle 1, a hatch 12 which is opened in a rotating manner and a gas transmission pipeline 13 for introducing Ar gas into the reaction kettle 1 are arranged in the middle of the reaction kettle 1, and a heater for heating is arranged in the reaction kettle 1;

a graphitizing tank 2, the graphitizing tank 2 is arranged at the lower part of the reaction kettle 1, and Si and Al which are used for containing the mixture ratio are arranged in the graphitizing tank 2₂O₃A cavity 21 for the powder mixture of (a);

the stirring mechanism 3 is arranged at the bottom of the graphitizing tank 2, and is used for stirring the substances in the accommodating cavity 21;

the coating platform 4 is arranged right above the graphitizing tank 2, the coating platform 4 is used for placing a graphite workpiece 10 to be coated, and the coating platform 4 gradually descends to be close to the graphitizing tank 2 along the vertical direction in the coating process of the graphite workpiece 10;

the exhaust mechanism 5 is installed at the top of the graphitizing tank 2, and comprises a sealing cover 51 for covering and sealing the graphitizing tank 2 and a gas transmission assembly 52 for communicating the coating platform 4 with the cavity 21, and the gas transmission assembly 52 transmits the SiO gas in the cavity 21 to the graphite workpiece 10; and

the driving mechanism 6 is installed on the reaction kettle 1, synchronously drives the stirring mechanism 3, the coating platform 4 and the exhaust mechanism 5 to work, and comprises a driving component 61 and a linkage component 62, wherein the driving component 61 is in transmission connection with the stirring mechanism 3, and the driving component 61 is in transmission connection with the coating platform 4 and the exhaust mechanism 5 through the linkage component 62.

The stirring mechanism 3 includes a stirring blade 31 and a rotating disk 32, the stirring blade 31 is rotatably installed in the graphitizing tank 2, the rotating shaft 311 thereon penetrates through the bottom of the graphitizing tank 2 and is disposed outside the graphitizing tank 2, the bottom of the rotating shaft 311 is provided with a cross groove 312, the rotating disk 32 is driven by the driving component 61 to be rotatably installed in the reaction kettle 1 and is located below the graphitizing tank 2, a butt joint shaft 321 coaxially disposed with the rotating shaft 311 is disposed thereon, and a quincunx head 322 correspondingly engaged with the cross groove 312 is disposed at the top of the butt joint shaft 321.

In the beginning, the stirring blade 31 is used for the reaction between Si and Al₂O₃The powder mixture of (1) is stirred to accelerate the mixing of Si and Al₂O₃The reaction rate of the powder mixture of (1) and ensuring Si and Al₂O₃And the present invention realizes the fast coupling of the stirring paddle 31 and the rotating disk 32 by the fast coupling of the rotating shaft 311 and the coupling shaft 321The speed drive is connected.

It is to be emphasized that Si and Al₂O₃Reaction to form SiO₂Gas, then at high temperature, to make SiO₂Reacting with Si to generate SiO gas, wherein the reaction conditions are 2230 ℃, and Si: melting point 1414 ℃ and boiling point 2900 ℃; al (Al)₂O₃: melting point 2303 deg.C, boiling point 3250 deg.C; SiO 2₂: melting point 1650 deg.C, boiling point 2230 deg.C; al: melting point is 660 ℃; boiling point 2327 ℃, SiO: melting point 1702 ℃ and boiling point 1880 ℃, so that at a high temperature of 2230 ℃, only Al is present in the reaction system₂O₃Solid, Si liquid and Al liquid, and SiO₂And SiO are both gases.

Further, the graphitization tank 2 is supported by a bracket 20 provided in the reaction vessel 1, and is mounted on the bracket 20 after the graphitization tank 2 enters the reaction vessel 1 through the port 12.

It is further explained that the hatch 11, the coating platform 4 and the sealing cover 51 are connected into a whole, when the hatch 11 is driven to lift by the hydraulic system 111 externally arranged outside the reaction kettle 1, the coating platform 4 and the sealing cover 51 are also lifted synchronously, and the lifting assembly 41 for driving the coating platform 4 to lift is also arranged on the hatch 11.

As shown in fig. 3 to 5, as a preferred embodiment, the coating platform 4 is driven by a lifting assembly 41 to move in a vertical direction, and the lifting assembly 41 includes:

an outer gear ring 411, wherein the outer gear ring 411 is rotatably mounted on the hatch 11 and is driven to rotate by the driving assembly 61 through the linkage assembly 62;

a plurality of rotary gears 412, which are arranged inside the outer ring gear 411 at equal intervals along the circumferential circumference of the outer ring gear 411 and are meshed with the internal teeth 413 on the outer ring gear 411;

the screw rods 414 are arranged in one-to-one correspondence with the rotary gears 412, the tops of the screw rods 414 are rotatably mounted on the hatch cover 11, and the bottoms of the screw rods 414 are rotatably mounted on the cover 51; and

the lead screw nut 415 is sleeved on the corresponding lead screw 414 and is installed on the coating platform 4, and the lead screw 414 rotates to drive the coating platform 4 to move through the lead screw nut 415.

Further, the internal teeth 413 on the outer ring gear 411 are arranged in a missing tooth manner, and the internal teeth 413 are divided into a plurality of tooth portions 4131 which are arranged at equal intervals along the circumferential direction of the outer ring gear 411.

Si and Al in the graphitization tank 2₂O₃After the powder mixture completely reacts to generate SiO gas, in the process of coating the graphite workpiece 10 by the SiO gas, in order to avoid the influence of waste gas CO generated by the reaction on the coating of the graphite workpiece 10, the driving mechanism 6 drives the outer gear ring 411 to rotate, the lead screw 414 matched with the outer gear ring 41 through the rotating gear 412 is rotated, and the coating platform 4 moves downwards by virtue of the lead screw nut 415 and is gradually close to the graphitization tank 2, and gas flow is formed on the graphite workpiece 10 by virtue of the movement of the coating platform 4, so that the influence of the waste gas is avoided.

Further, in order to better coat the graphite workpiece 10, after the coating platform 4 descends for a certain distance, the coating platform 4 stops for a certain time, so that the graphite workpiece 10 performs a coating reaction, and in the second step, the graphite workpiece 10 continues to move downwards after reacting for a certain time, and the reaction is repeated, so that the coating reaction effect of the graphite workpiece 10 is ensured, and the interference of waste gas CO is avoided.

As shown in fig. 14, as a preferred embodiment, a material rest 42 for supporting the graphite workpiece 10 is disposed at a central line position of the coating platform 4, a hollow hole 421 is disposed on the material rest 42, and a plurality of air holes 43 are uniformly distributed at a position of the coating platform 4 facing the material rest 42.

It should be noted that the coating platform 4 is provided with the hollow holes 421, and the hollow holes 421 enable the local position of the lower end face of the graphite workpiece 10 to be coated first, and in the subsequent process, the support points are used for lifting, so that the problem that the bottom end face of the graphite workpiece 10 cannot be coated comprehensively can be effectively solved.

As shown in fig. 12 and 13, in a preferred embodiment, the gas delivery assembly 52 includes a gas exhaust pipe 521 and a gas exhaust hood 522, the gas exhaust pipe 521 is disposed between the coating platform 4 and the cap 51 and includes a steel pipe portion 5211 and a hose portion 5212, and the gas exhaust hood 522 is disposed in a funnel shape, covers the graphite workpiece 10, and is connected to the hose portion 5212.

Further, an exhaust valve 53 is disposed at a connection position of the steel pipe portion 5211 and the hose portion 5212, the exhaust valve 53 is rotatably sleeved on the steel pipe portion 5211, a valve closing plate 531 is disposed in the exhaust valve 53, and a valve compensation closing plate 532 matched with the valve closing plate 531 is disposed on the steel pipe portion 5211.

The lid 51 closes the top opening of the graphitization tank 2, so that Si and Al in the graphitization tank 2 are mixed₂O₃When the powder mixture is reacted, the cavity 21 in the graphitization tank 2 is a closed space, and after the reaction is completed, the silicon oxide gas needs to be discharged, at this time, the exhaust pipe 521 needs to be opened, and the valve closing plate 531 rotates in a staggered manner relative to the valve compensation closing plate 532 by means of the rotation of the exhaust valve 53, so that the exhaust pipe 521 is opened.

It is further explained that the rotation of the exhaust valve 53 is realized by the cooperation of the driving assembly 61 and the linkage assembly 62, when the reaction is performed in the interior of the graphitization tank 2 to generate the silicon oxide gas, the driving assembly 61 and the linkage assembly 62 are not matched, the exhaust pipe 521 cannot be opened, and the Si and Al in the interior of the graphitization tank 2 are ensured₂O₃The reaction environment of the powder mixture of (1) is stable.

As shown in fig. 5, as a preferred embodiment, the driving assembly 61 includes:

the motor 611, the said motor 611 is mounted to the bottom of the said reaction vessel 1;

a main shaft 612, wherein the main shaft 612 is vertically installed in the reaction kettle 1 and is driven by the motor 611 to rotate; and

a set of drive sprockets 613, the set of drive sprockets 613 being mounted between the main shaft 612 and the rotating disk 32, which drive the rotating disk 32 to rotate with the main shaft 612.

As further shown in fig. 3 and 5, the linkage assembly 62 includes:

a lifting ring 621, which is provided along the circumferential direction of the rotating disk 32, and includes a convex lifting portion 6211 and a concave settling portion 6212;

the transmission shaft 622 is vertically and rotatably mounted on the hatch 11, can be adjusted in an up-and-down manner along the axial direction, and is slidably arranged on the lifting ring 621 in an abutting manner at the bottom of the transmission shaft 622;

a driving gear 623, wherein the driving gear 623 is mounted at the top of the main shaft 612;

a transmission gear 624, wherein the transmission gear 624 is installed on the top of the transmission shaft 622, and when the transmission shaft 622 collides with the lifting part 6211, the transmission gear 624 is meshed with the driving gear 623 and the external teeth 4112 on the external gear ring 411 respectively; and

the transmission chain wheel 625 is rotatably mounted in the middle of the transmission shaft 622 and is arranged statically in the vertical direction relative to the transmission shaft 622, and when the transmission shaft 622 is lifted, a key 6221 on the transmission chain wheel 625 is inserted and matched with a key groove 6251 on the transmission chain wheel 625;

the rotating chain wheel 626 is sleeved on the exhaust valve 53, and is connected with the transmission chain wheel 625 through a transmission chain 627.

It should be noted that the motor 611 drives the main shaft 612 to rotate, the main shaft drives the rotating disc 32 to rotate through the driving chain wheel set 613, the rotating disc 32 drives the stirring blade 31 to rotate, and it is noted that the lifting ring 621 mounted on the rotating disc 32 rotates synchronously with the rotating disc 32, at the stage when the graphitization tank 2 is sealed to react to generate the silicon oxide gas, the settling portion 6212 on the lifting ring 621 collides with the bottom of the transmission shaft 622, the transmission gear 624 is separated from the driving gear 623, at this time, the driving assembly 61 and the linkage assembly 62 are in a separated state, and after the reaction in the graphitization tank 2 is completed, the lifting portion 6211 on the lifting ring 621 collides with the bottom of the transmission shaft 622, the transmission gear 624 is meshed with the driving gear 623, and the transmission gear 624 is meshed with the external teeth 4112 on the external teeth ring 411, and the external teeth 411 are driven to rotate, the lowering of the coating platform 4 is also achieved.

It is further noted that, synchronously, after the transmission shaft 622 is lifted, the key 6221 on the transmission shaft 622 is inserted and matched with the key groove 6251 on the transmission chain wheel 625, so that the transmission chain wheel 625 rotates, the exhaust valve 53 rotates through the matching of the rotating chain wheel 626 and the transmission chain 627, and the silicon oxide gas in the graphitization tank 2 is continuously discharged through the stirring of the stirring blade 31.

It should be emphasized that, by the arrangement of the lifting ring 621 and the linkage assembly 62, the tight connection from the reaction stage to the exhaust stage of the silicon oxide gas in the graphitization tank 2 is realized, and at the same time, the lowering of the coating platform is performed synchronously with the exhaust of the silicon oxide gas.

As shown in fig. 14, in addition, several groups of lifting assemblies 44 are arranged on the circumference of the coating platform 4 at equal intervals, and each lifting assembly 44 comprises:

the lifting rod 441 penetrates through the coating platform 4, and an elastic piece 442 is arranged between the bottom of the lifting rod 441 and the coating platform 4;

a guide rod 443, wherein the guide rod 443 is arranged on the coating platform 4 in a penetrating manner and is parallel to the lifting rod 441;

a lift arm 444, wherein the lift arm 444 is mounted on the top of the lift rod 441 and the guide rod 443, and is arranged to be directed to the center of the coating platform 4; and

a lifting block 445, the lifting block 445 being mounted on the end of the lifting arm 444 directed towards the centre of the coating platform 4.

It should be noted that, in order to complete coating at each part of the graphite workpiece 10, in the process that the coating platform 4 gradually approaches the graphitizing tank 2, the lifting arm 444 is lifted by virtue of the interference between the lifting rod 441 and the cover 51, the graphite workpiece 10 is lifted by virtue of the lifting arm 444, the lower end face of the bottom is exposed, the lower end face of the graphite workpiece 10 is subjected to coating reaction, and the part of the graphite workpiece 10, which is touched by the lifting block 445, is in the previous process, and the coating reaction is completed.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.