CN113699518A

CN113699518A - Low-temperature preparation device for silicon carbide coating on metal surface

Info

Publication number: CN113699518A
Application number: CN202110992466.4A
Authority: CN
Inventors: 丁柳宁; 周李伟; 陈凯
Original assignee: Zhejiang Liufang Carbon Technology Co ltd
Current assignee: Zhejiang Liufang Semiconductor Technology Co.,Ltd.
Priority date: 2021-08-27
Filing date: 2021-08-27
Publication date: 2021-11-26
Anticipated expiration: 2041-08-27
Also published as: CN113699518B

Abstract

The invention discloses a low-temperature preparation device for silicon carbide coating on metal surface, which is characterized by comprising a hollow reaction chamber, an upper sealing block and a lower sealing block; an induction coil is wound on the outer side wall of the reaction chamber; The block is provided with an air outlet and an exhaust port, a paint mixing box is arranged outside the reaction chamber, a paint delivery pump is arranged in the paint mixing box, and a paint mixing box and the lower sealing block are arranged between the paint mixing box and the reaction chamber. The feeding pipe and the discharging pipe are arranged between the paint mixing box and the upper sealing block with a return pipe communicating with the reaction chamber. The solenoid valve is connected with a pressure gauge on the return pipe, and a pressure relief valve with adjustable pressure is arranged on the return pipe. The invention provides a low-temperature preparation device for silicon carbide coating on metal surface, so that ultra-thick and dense silicon carbide coating is formed on the metal surface, meanwhile, the heating uniformity of workpiece is ensured, and the temperature required for preparation is reduced.

Description

Low-temperature preparation device for silicon carbide coating on metal surface

Technical Field

The invention relates to the field of preparation of silicon carbide coatings, in particular to a low-temperature preparation device for a silicon carbide coating on a metal surface.

Background

Silicon carbide is widely applied to the fields of aerospace, aviation, microelectronics, automobiles, laser, mining industry, atomic energy and the like due to high hardness, high abrasion resistance, high bending strength, excellent oxidation resistance, acid-base corrosion resistance and high-temperature mechanical properties. The high-purity silicon carbide coating plays an important role in high-temperature protection, oxidation resistance and corrosion resistance in the fields. The compact silicon carbide coating is prepared on the metal surface, so that the metal material can be prevented from being etched by hydrogen, oxygen, nitride and other gases in a high-temperature environment. However, the existing silicon carbide coating has the thickness and is thinned, the silicon carbide coating needs to be heated from the outside during sintering, the required heating temperature is higher, meanwhile, the problem that a metal piece is heated unevenly exists, and the metal piece is required to be rotated and arranged in a heating box body usually, so that the metal piece is rotated in the heating process, and the heating uniformity is improved.

Disclosure of Invention

The invention aims to solve the technical problem of the prior art, and provides a low-temperature preparation device for a silicon carbide coating on a metal surface, so that an ultra-thick and dense silicon carbide coating is formed on the metal surface, the heating uniformity of a workpiece is ensured, and the temperature required by preparation is reduced.

The technical scheme adopted by the invention for solving the technical problems is as follows: the utility model provides a low temperature preparation facilities of metal surface carborundum coating which characterized in that: the device comprises a hollow reaction chamber, an upper sealing block arranged on the upper part of the reaction chamber in a sliding way, and a lower sealing block arranged on the lower part of the reaction chamber in a sliding way, wherein the reaction chamber, the upper sealing block and the lower sealing block are made of non-conductive materials, an induction coil is wound on the outer side wall of the reaction chamber and is connected with an induction power supply, an air conveying port and an air exhaust port which are communicated with the reaction chamber are arranged on the upper sealing block, the air conveying port is connected with a pressure pump, the air exhaust port is connected with an air exhaust pump, a coating mixing box is arranged outside the reaction chamber, a coating conveying pump is arranged in the coating mixing box, a conveying pipe and a discharging pipe which are communicated with the reaction chamber are arranged between the coating mixing box and the lower sealing block, a material return pipe which is communicated with the reaction chamber is arranged between the coating mixing box and the upper sealing block, the coating conveying pump is connected with the conveying pipe, and a one-way valve which limits the coating from the coating mixing box to the reaction chamber is arranged on the conveying pipe, the discharge pipe is provided with a two-position two-way electromagnetic valve, two works of the two-position two-way electromagnetic valve are respectively a communicating position and a non-communicating position, the feed back pipe is communicated with a pressure gauge, and the feed back pipe is provided with a pressure-adjustable pressure relief valve.

In another improvement, the paint delivery pump is a variable pump.

The improved structure comprises a base, a lower sealing block, an upper sealing block, a top plate, a lifting cylinder, a middle sleeve, a left lug, a right lug, a left slide way, a right slide way, a left slide block, a right slide block, a first connecting rod group, a second connecting rod group, a third connecting rod group and a fourth connecting rod group, wherein the lower sealing block is fixed on the base, the upper sealing block is fixed on the top plate, the lifting cylinder connected with the top plate is arranged on the top plate, the middle sleeve is sleeved outside the reaction chamber and fixedly connected with the reaction chamber, the left side of the middle sleeve extends to form the left lug, the right side of the middle sleeve extends to form the right lug, the left slide way is arranged on the left lug, the right slide way is arranged on the right lug, the left slide way is provided with the left slide block in a sliding manner, the right slide block is arranged in the right slide way, the first connecting rod group is hinged between the top plate and the left slide block, the base and the left slide block are hinged to form the second connecting rod group, the third connecting rod group is hinged between the top plate and the right slide block.

And the first connecting rod group, the second connecting rod group, the third connecting rod group and the fourth connecting rod group are respectively composed of two connecting rods sharing the same rotating shaft.

The coating mixing box is further improved, a mixing mechanism is arranged in the coating mixing box, the mixing mechanism comprises a mixing seat, a mixing motor, a crank connected with the output end of the mixing motor, a planetary gear connected to the outer end of the crank, a first connecting rod fixedly connected with the central shaft of the planetary gear, a first rotating shaft fixed to the outer end of the first connecting rod, a second connecting rod fixed to the first rotating shaft, and a second rotating shaft fixed to the second connecting rod, the axis of the second rotating shaft is coincident with the axis of the central shaft of the planetary gear, the circumferential projections of the first connecting rod and the second connecting rod are coincident, an inner gear ring meshed with the planetary gear is formed on the mixing seat, the first rotating shaft is sleeved with a first swing rod and a second swing rod which are mutually forked, the second rotating shaft is sleeved with a third swing rod and a fourth swing rod which are mutually forked, and a first limiting sleeve and a second limiting sleeve are relatively rotatably arranged on the mixing seat, the first swing rod penetrates through the first limiting sleeve, the second swing rod penetrates through the second limiting sleeve, a first connecting sleeve is hinged between the outer end of the first swing rod and the outer end of the third swing rod, a second connecting sleeve is hinged between the outer end of the second swing rod and the outer end of the fourth swing rod, and stirring blades are respectively sleeved on the first connecting sleeve and the second connecting sleeve.

And the upper side surface of the lower sealing block is provided with a groove.

And the coating in the coating mixing box is formed by mixing silicon carbide powder, an organic solvent, an adhesive and a sintering agent according to a certain proportion.

In a further improvement, the sintering agent is carbon or boron.

Compared with the prior art, the invention has the advantages that: in the preparation process of the silicon carbide coating on the metal surface, an upper sealing block or a lower sealing block is opened, a metal workpiece is placed in a reaction chamber, silicon carbide powder, an organic solvent, a binder and a sintering agent are mixed and ground according to a certain proportion, finally, a coating is placed in a coating mixing box, an exhaust pump works, gas in the reaction chamber is exhausted to form vacuum, meanwhile, the pressure value of a pressure release valve is set, the coating in the coating mixing box is conveyed into the reaction chamber by a coating conveying pump, in the coating conveying process, a two-position two-way electromagnetic valve is located at a non-communicated working position, a one-way valve can limit the backflow of the coating in the reaction chamber, the coating is filled in the reaction chamber until the pressure on a material return pipe is greater than the pressure value set by the pressure release valve, redundant coating flows back into the coating mixing box through the material return pipe, the pressure maintaining of the coating in the reaction chamber is realized, and the coating can be fully distributed at all positions on the surface of the metal workpiece, the place which can not be sprayed or is difficult to be sprayed in place can not exist, the uniformity of coating is greatly improved, after the pressure is maintained for a period of time, the coating conveying pump stops working, the two-position two-way electromagnetic valve is switched to the communicated working position, meanwhile, the pressure pump gradually introduces inert gas into the reaction chamber through the gas transmission port, the coating in the reaction chamber is gradually discharged into the coating mixing box through the discharge pipe, then, the cooperative work of the exhaust pump and the pressure pump is utilized, the pressure of 2500 plus 4000Pa is kept in the reaction chamber, meanwhile, the induction coil outside the reaction chamber is introduced with high-frequency alternating current, because the upper sealing block, the reaction chamber and the lower sealing block are made of non-conductive materials, the upper sealing block, the reaction chamber and the lower sealing block can not generate heat under the action of the induction coil, only the interior of the metal workpiece in the reaction chamber is heated, and therefore, the metal workpiece is heated to the temperature of 350 plus 400K, the method has the advantages that the evaporation of an organic solvent is realized, a compact silicon carbide powder film is formed on the surface of the metal, then, the pressure in the reaction chamber is reduced, the pressure of 1000-1500Pa is kept in the reaction chamber, meanwhile, the temperature in the reaction chamber is adjusted to 1500-1700K, and the reaction chamber is heated for 20-40min to form the ultra-thick and dense silicon carbide coating.

Drawings

FIG. 1 is a schematic structural diagram of an apparatus for low-temperature production of a silicon carbide coating on a metal surface according to an embodiment of the present invention;

FIG. 2 is a schematic view showing a connection structure of an upper block, a reaction chamber and a lower block in the embodiment of the present invention;

fig. 3 is a schematic structural diagram of a mixing mechanism in an embodiment of the present invention.

Detailed Description

The invention is described in further detail below with reference to the accompanying examples.

As shown in fig. 1 to 3, the low-temperature preparation apparatus for a silicon carbide coating on a metal surface in this embodiment includes a reaction chamber 12, an upper seal block 11, a lower seal block 13, a base 32, a top plate 31, a first linkage 361, a second linkage 362, a third linkage 363, a fourth linkage 364, an induction coil 2, an induction power supply 21, a pressure pump 4, an exhaust pump 5, a paint mixing box 9, a mixing mechanism, a paint delivery pump 7, a check valve 81, a two-position two-way solenoid valve 82, a pressure gauge 84, and a pressure relief valve 83.

Wherein, the reaction chamber 12 is hollow and hollow, the upper sealing block 11 is arranged on the upper part of the reaction chamber 12 in a sliding way, the lower sealing block 13 is arranged on the lower part of the reaction chamber 12 in a sliding way, the reaction chamber 12, the upper sealing block 11 and the lower sealing block 13 are all made of non-conductive materials, the outer side wall of the reaction chamber 12 is wound with the induction coil 2, the induction coil 2 is connected with the induction power supply 21, the upper sealing block 11 is provided with the air transmission port 41 and the air exhaust port 51 which are communicated with the reaction chamber 12, the air transmission port 41 is connected with the pressure pump 4, the air exhaust port 51 is connected with the exhaust pump 5, the exterior of the reaction chamber 12 is provided with the paint mixing box 9, the paint mixing box 9 is provided with the paint conveying pump 7, preferably, the paint conveying pump 7 is a variable pump to realize the control of the paint conveying flow, the material conveying pipe 61 and the material discharging pipe 62 which are communicated with the reaction chamber 12 are arranged between the paint mixing box 9 and the lower sealing block 13, and the material returning pipe 63 which is communicated with the reaction chamber 12 is arranged between the paint mixing box 9 and the upper sealing block 11, the coating material conveying pump 7 is connected with the conveying pipe 61, a one-way valve 81 for limiting the coating material to flow from the coating material mixing box 9 to the reaction chamber 12 is arranged on the conveying pipe 61, a two-position two-way electromagnetic valve 82 is arranged on the discharging pipe 62, two works of the two-position two-way electromagnetic valve 82 are respectively a communicating position and a non-communicating position, a pressure gauge 84 is communicated with the material returning pipe 63, and a pressure-adjustable pressure relief valve 83 is arranged on the material returning pipe 63.

In addition, in order to facilitate the opening of the reaction chamber 12, the sliding arrangement structure of the upper sealing block 11 and the lower sealing block 13 is, as shown in fig. 2, the lower sealing block 13 is fixed on the base 32, the upper sealing block 11 is fixed on the top plate 31, the lifting cylinder 37 connected with the top plate 31 is arranged on the top plate 31, the middle sleeve 33 is sleeved outside the reaction chamber 12, the middle sleeve 33 is fixedly connected with the reaction chamber 12, the left side of the middle sleeve 33 extends to form a left ear 34, the right side of the middle sleeve 33 extends to form a right ear 35, the left ear 34 is formed with a left slideway 341, the right ear 35 is formed with a right slideway 351, the left slideway 341 is slidably formed with a left slider 342, the right slideway 351 is slidably formed with a right slider 352, a first connecting rod group 361 is hinged between the top plate 31 and the left slider 342, a second connecting rod group 362 is hinged between the base 32 and the left slider 342, and a third connecting rod group 363 is hinged between the top plate 31 and the right slider 352, a fourth linkage 364 is articulated between the base 32 and the right slider 352. When a metal workpiece needs to be placed into the reaction chamber 12, the lifting cylinder 37 retracts, the top plate 31 pulls the upper sealing block 11 up, meanwhile, the middle sleeve 33 also moves upwards under the action of the four connecting rod groups, and therefore the lower sealing block 13 can be opened, in order to facilitate material placement, a groove can be formed in the upper side face of the lower sealing block 13, the metal workpiece is placed in the groove, or a placing frame is arranged in the reaction chamber 12, the metal workpiece enters from the top or the bottom of the reaction chamber 12 and is placed on the placing frame of the reaction chamber 12, after the metal workpiece is placed, the lifting cylinder 37 resets and extends out, and the upper sealing block 11 and the lower sealing block 13 achieve plugging of the upper part and the lower part of the reaction chamber 12.

Further, in order to improve the stability of the link transmission, each of the first link group 361, the second link group 362, the third link group 363, and the fourth link group 364 is composed of two links sharing the same rotation axis.

In addition, in order to improve the uniformity of the paint and prevent the paint from settling, a mixing mechanism is arranged in the paint mixing box 9, as shown in fig. 3, the mixing mechanism comprises a mixing base 91, a mixing motor, a crank connected with the output end of the mixing motor, a planetary gear 92 connected with the outer end of the crank, a first connecting rod 931 fixedly connected with the central shaft of the planetary gear 92, a first rotating shaft fixed on the outer end of the first connecting rod 931, a second connecting rod 932 fixed on the first rotating shaft, a second rotating shaft 94 fixed on the second connecting rod 932, the axial line of the second rotating shaft 94 is coincident with the central shaft of the planetary gear 92, the circumferential projections of the first connecting rod 31 and the second connecting rod 932 are coincident, an inner gear ring 911 engaged with the planetary gear 92 is formed on the mixing base 91, and a first swing rod 951 and a second swing rod 952 which are branched are sleeved on the first rotating shaft, the third swing rod 953 and the fourth swing rod 954 which are forked are sleeved on the second rotating shaft 94, a first limiting sleeve 971 and a second limiting sleeve 92 are arranged on the mixing seat 91 in a relative rotating mode, the first swing rod 951 penetrates through the first limiting sleeve 971, the second swing rod 952 penetrates through the second limiting sleeve 972, a first connecting sleeve 96 is hinged between the outer end of the first swing rod 951 and the outer end of the third swing rod 953, a second connecting sleeve is hinged between the outer end of the second swing rod 952 and the outer end of the fourth swing rod 954, and stirring blades are respectively sleeved on the first connecting sleeve 96 and the second connecting sleeve. The mixing motor drives the crank to rotate, the crank drives the planetary gear 92 to rotate around the inner gear ring 911 of the mixing seat 91, the planetary gear 92 drives the four swing rods to swing synchronously through the two connecting rods, specifically, the first swing rod 951 and the third swing rod 953 swing as a group, the second swing rod 952 and the fourth swing rod 954 swing as a group, and the two groups of swing rods arranged oppositely swing in a reciprocating manner, so that the coating in the coating mixing box 9 is fully mixed, and the coating is prevented from precipitating.

Finally, the invention also provides a low-temperature preparation method of the silicon carbide coating on the metal surface, which comprises the following steps:

step S1, mixing and grinding titanium carbide powder, an organic solvent, a bonding agent and a sintering agent according to a certain proportion, and finally putting the coating into a coating mixing box 9;

step S2, opening the upper sealing block 11 or the lower sealing block 13, and placing the metal workpiece in the reaction chamber 12;

step S3, setting the pressure-maintaining pressure when the paint is coated on the surface of the metal workpiece in the reaction chamber by setting the pressure-releasing pressure of the pressure-releasing valve 83, conveying the paint in the paint mixing box 9 into the reaction chamber 12 by the paint conveying pump 7, wherein the two-position two-way electromagnetic valve 82 is in a non-communicated working position during the paint conveying process, the one-way valve 81 can limit the backflow of the paint in the reaction chamber 12, the paint is fully filled in the reaction chamber 12 until the pressure on the material return pipe 63 is greater than the pressure value set by the pressure-releasing valve 83, and the redundant paint flows back into the paint mixing box 9 through the material return pipe 63, so that the pressure-maintaining is carried out on the paint in the reaction chamber 12, and each position on the surface of the metal workpiece can be fully filled with the paint, and the pressure-maintaining is carried out for 10-30 min;

step S4, stopping the operation of the coating material delivery pump 7, switching the two-position two-way electromagnetic valve 82 to a communication operation position, simultaneously, gradually introducing inert gas into the reaction chamber 12 through the gas delivery port 41 by the pressure pump 4, gradually discharging the coating material in the reaction chamber 12 into the coating material mixing box 9 through the discharge pipe 62, then, utilizing the cooperative operation of the exhaust pump 5 and the pressure pump 4 to ensure that the pressure in the reaction chamber 12 is kept at 2500 plus 4000Pa, simultaneously, introducing high-frequency alternating current into the induction coil 2 outside the reaction chamber 12, heating the interior of the metal workpiece in the reaction chamber 12 to the temperature of 350 plus 400K, realizing the evaporation of the organic solvent in the coating material, and forming a compact silicon carbide powder film on the metal surface;

step S5, reducing the pressure in the reaction chamber 12 to keep the pressure inside the reaction chamber 12 at 1500 Pa-1000 deg.C, adjusting the temperature inside the reaction chamber 12 to 1700K-1500 deg.C, and heating for 20-40min to form the ultra-thick dense silicon carbide coating.

Among them, preferably, the sintering agent is carbon or boron.

In conclusion, in the preparation process of the silicon carbide coating on the metal surface, the upper sealing block 11 or the lower sealing block 13 is opened, the metal workpiece is placed in the reaction chamber 12, the silicon carbide powder, the organic solvent, the adhesive and the sintering agent are mixed and ground according to a certain proportion, finally the coating is placed in the coating mixing box 9, the exhaust pump 5 works, the gas in the reaction chamber 12 is exhausted to form vacuum, bubbles are prevented from being generated in the process of inputting the coating into the reaction chamber 12, meanwhile, the pressure value of the pressure relief valve 83 is set, the coating in the coating mixing box 9 is conveyed into the reaction chamber 12 by the coating conveying pump 7, in the coating conveying process, the two-position two-way electromagnetic valve 82 is in a non-communication working position, the one-way valve 81 can limit the coating in the reaction chamber 12 to flow back, the reaction chamber 12 is filled with the coating until the pressure on the material return pipe 84 is greater than the pressure value set by the pressure relief valve 83, the redundant coating flows back to the coating mixing box 9 through the material return pipe 84 to realize pressure maintaining on the coating in the reaction chamber 12, so that each position of the surface of the metal workpiece can be fully covered with the coating, and a place which cannot be or is difficult to be sprayed in place can not exist, the coating uniformity is greatly improved, after the coating is maintained for a period of time, the coating conveying pump 7 stops working, the two-position two-way electromagnetic valve 82 is switched to a communicated working position, meanwhile, the inert gas is gradually introduced into the reaction chamber 12 through the gas transmission port 41 by the pressure pump 4, the coating in the reaction chamber 12 is gradually discharged into the coating mixing box 9 through the discharge pipe 62, then, the pressure of 2500 plus 4000Pa is maintained in the reaction chamber 12 by utilizing the cooperative work of the exhaust pump 5 and the pressure pump 4, meanwhile, the high-frequency alternating current is introduced into the induction coil 2 outside the reaction chamber 12, and the upper sealing block 11, the reaction chamber 12 and the lower sealing block 13 are all made of non-conductive materials, the upper sealing block 11, the reaction chamber 12 and the lower sealing block 13 do not generate heat under the action of the induction coil 2, only the inside of the metal workpiece in the reaction chamber 12 is heated, thus, the metal workpiece is heated to the temperature of 350-400K to realize the evaporation of the organic solvent, after a compact silicon carbide powder film is formed on the metal surface, the pressure inside the reaction chamber 12 is reduced, so that the inside of the reaction chamber 12 is maintained at a pressure of 1000-1500Pa, meanwhile, the temperature in the reaction chamber 12 is adjusted to 1500-1700K, and the silicon carbide coating with super-thick density is formed after heating for 20-40min, the invention directly heats the inside of the metal workpiece by utilizing the induction heating principle, the coating transfers heat from inside to outside and is sintered, so that the heating uniformity of the workpiece is ensured, meanwhile, a heat source is more fully and directly utilized, and the temperature required by preparation is reduced.

Claims

1. The utility model provides a low temperature preparation facilities of metal surface carborundum coating which characterized in that: comprises a hollow reaction chamber (12), an upper sealing block (11) arranged on the upper part of the reaction chamber (12) in a sliding way, and a lower sealing block (13) arranged on the lower part of the reaction chamber (12) in a sliding way, wherein the reaction chamber (12), the upper sealing block (11) and the lower sealing block (13) are all made of non-conductive materials, an induction coil (2) is wound on the outer side wall of the reaction chamber (12), the induction coil (2) is connected with an induction power supply (21), an air conveying port (41) and an air exhaust port (51) which are communicated with the reaction chamber (12) are arranged on the upper sealing block (11), the air conveying port (41) is connected with a pressure pump (4), the air exhaust port (51) is connected with an exhaust pump (5), a coating mixing box (9) is arranged outside the reaction chamber (12), a coating conveying pump (7) is arranged in the coating mixing box (9), a conveying pipe (61) and a conveying pipe (62) which are communicated with the reaction chamber (12) are arranged between the coating mixing box (9) and the lower sealing block (13), be provided with return pipe (63) with reacting chamber (12) intercommunication between coating mixing box (9) and last sealing block (11), coating delivery pump (7) are connected with conveying pipeline (61), be provided with check valve (81) that restriction coating flowed to the reacting chamber from coating mixing box (9) on conveying pipeline (61), be provided with two-way solenoid valve (82) on row material pipe (62), two works of two-way solenoid valve (82) are for being respectively a intercommunication position and a non-intercommunication position, the intercommunication has a manometer (84) on return pipe (63), be provided with pressure adjustable pressure relief valve (83) on return pipe (63).

2. The apparatus for low temperature production of silicon carbide coatings on metal surfaces as claimed in claim 1, wherein: the coating material delivery pump (7) is a variable pump.

3. The apparatus for low temperature production of silicon carbide coatings on metal surfaces as claimed in claim 1, wherein: the lower sealing block (13) is fixed on the base (32), the upper sealing block (11) is fixed on the top plate (31), a lifting cylinder (37) connected with the top plate (31) is arranged on the top plate (31), a middle sleeve (33) is sleeved outside the reaction chamber (12), the middle sleeve (33) is fixedly connected with the reaction chamber (12), a left lug (34) extends from the left side of the middle sleeve (33), a right lug (35) extends from the right side of the middle sleeve (33), a left slideway (341) is arranged on the left lug (34), a right slideway (351) is arranged on the right lug (35), a left sliding block (342) is arranged in the left slideway (341) in a sliding manner, a right sliding block (352) is arranged in the right slideway (351) in a sliding manner, a first connecting rod group (361) is hinged between the top plate (31) and the left sliding block (342), and a second connecting rod group (362) is hinged between the base (32) and the left sliding block (342), a third connecting rod group (363) is hinged between the top plate (31) and the right sliding block (352), and a fourth connecting rod group (364) is hinged between the base (32) and the right sliding block (352).

4. The apparatus for low temperature production of silicon carbide coatings according to claim 3, wherein: the first connecting rod group (361), the second connecting rod group (362), the third connecting rod group (363) and the fourth connecting rod group (364) are respectively composed of two connecting rods sharing the same rotating shaft.

5. The apparatus for low temperature production of silicon carbide coatings according to claim 4, wherein: the coating mixing box is characterized in that a mixing mechanism is arranged in the coating mixing box (3), the mixing mechanism comprises a mixing seat (91), a mixing motor, a crank connected with the output end of the mixing motor, a planetary gear (92) connected to the outer end of the crank, a first connecting rod (931) fixedly connected with the central shaft of the planetary gear (92), a first rotating shaft fixed to the outer end of the first connecting rod (931), a second connecting rod (932) fixed to the first rotating shaft, a second rotating shaft (94) fixed to the second connecting rod (932), the axis of the second rotating shaft (94) is overlapped with the axis of the central shaft of the planetary gear (92), the circumferential projections of the first connecting rod (931) and the second connecting rod (932) are overlapped, an inner gear ring (911) meshed with the planetary gear (92) is formed on the mixing seat (91), a first swinging rod (951) and a second swinging rod (952) which are branched mutually are sleeved on the first rotating shaft, the second rotating shaft (94) is sleeved with a third swing rod (953) and a fourth swing rod (954) which are branched mutually, a first limit sleeve (971) and a second limit sleeve (972) are arranged on the mixing seat (91) in a relative rotating mode, the first swing rod (951) penetrates through the first limit sleeve (971), the second swing rod (952) penetrates through the second limit sleeve (972), a first connecting sleeve (971) is hinged between the outer end of the first swing rod (951) and the outer end of the third swing rod (953), a second connecting sleeve (972) is hinged between the outer end of the second swing rod (952) and the outer end of the fourth swing rod (954), and stirring blades are respectively sleeved on the first connecting sleeve (971) and the second connecting sleeve (972).

6. The apparatus for low temperature production of silicon carbide coatings on metal surfaces as claimed in claim 1, wherein: the upper side surface of the lower sealing block (13) is provided with a groove.

7. The apparatus for low temperature production of silicon carbide coatings on metal surfaces as claimed in claim 1, wherein: the coating in the coating mixing box (9) is formed by mixing silicon carbide powder, an organic solvent, an adhesive and a sintering agent according to a certain proportion.

8. The apparatus for low temperature production of silicon carbide coatings according to claim 7, wherein: the sintering agent is carbon or boron.