143 results about "Hot filament" patented technology

The invention discloses a poly-Si film preparation method based on a vertical double-layer hot wire array thermal field design, which changes the surface temperature of a hot wire and the range of a cracking high-temperature region by adjusting the interlayer spacing of a double-layer hot wire array and the current of the double-layer hot wire, expands the cracking time and the cracking space of silane, promotes secondary cracking of the silane, and improves the yield of the poly-Si film. Components and concentration distribution of a silane cracking intermediate product reaching the surface of the substrate can be effectively controlled, and the ratio of SiH / SiH2 active groups is increased; and depositing the poly-Si thin film under the vacuum of 0.5 Pa-5. 0Pa, the substrate temperature of 200-560 DEG C and the deposition time of 10-60 minutes, after deposition is finished, raising the substrate temperature to 200-650 DEG C, and carrying out vacuum annealing on the grown poly-Si thin film to obtain the high-crystallization-rate poly-Si thin film. According to the method, the poly-Si thin film is grown by using a vertical double-layer hot wire array thermal field design, a high-temperature hot wire silane cracking technology and a vacuum annealing technology, and the crystallization quality of the poly-Si thin film can be obviously improved.

The invention relates to a method for preparing a low-temperature silicon nitride film, which adopts a hot filament chemical vapor deposition technology and comprises the following steps of: placing a substrate on a support plate and feeding the support plate into a vacuum reaction chamber; introducing required process gas into the vacuum reaction chamber, wherein the process gas comprises any one or both of ammonia gas and nitrogen gas, hydrogen gas and silane; and dynamically adjusting the temperature of the hot filament, and depositing on the substrate to obtain the required silicon nitride film. In addition, the invention also relates to equipment for preparing the low-temperature silicon nitride film by adopting the method for preparing the low-temperature silicon nitride film. The hot filament chemical vapor deposition technology is adopted, the compact silicon nitride thin film can be prepared when the temperature of the substrate is higher than the room temperature, the application field of equipment is greatly widened, the silicon nitride thin film deposited under the condition that the temperature of the substrate is kept low can be produced under the proper air pressure, and the production efficiency is improved. And manufacturing of HBC cells and perovskite cells in the photovoltaic field is facilitated.

The present invention discloses a method for preparing nano-diamonds based on graphene vertical sheets. The present invention utilizes a hot wire chemical vapor deposition system to grow graphene vertical sheets containing tantalum atoms, and transforms the graphene vertical sheets into nano-diamonds under relatively low pressure conditions. The method has the characteristics of mild conditions and low cost. The method has low requirements on equipment, simple process and easy operation. The method has important scientific significance and value for developing a new method for preparing nano-diamonds.

The invention discloses a CVD diamond thick film and a preparation method and application thereof. The thickness of the CVD diamond thick film is not less than 0.5 mm. The method comprises the following steps: (1) adopting a first growth process on a substrate to obtain an unmodified CVD diamond film; (2) carrying out modification treatment on the unmodified CVD diamond film obtained in the step (1) by adopting a second treatment process to obtain a modified CVD diamond film; (3) carrying out transition treatment on the modified CVD diamond film obtained in the step (2) by adopting a third transition process; and (4) the step (1) to the step (3) are cyclically operated, the cycle number is n, and the CVD diamond thick film is obtained. According to the method, through process control, the secondary nucleation process in the deposition process is achieved, the grain size is consistent in the long-time deposition process, no obvious columnar crystal exists on the diamond section, the good mechanical property is achieved, the thickness of the prepared CVD thick film reaches the millimeter level, and the hot wire carbon deposition phenomenon is remarkably relieved.

The invention discloses an ion source current control device and system, and relates to the field of circuits, the ion source current control device comprises a sampling circuit, a control circuit and a power supply circuit, the control circuit is connected with the sampling circuit, the ion source current of a neutron tube can be detected in real time, and power supply of a hot wire is controlled in real time by adopting a hardware circuit feedback mode. The current stability of the ion source is rapidly maintained, the calculation delay of a software mode is eliminated, and the control circuit can realize the adjustment of the duty ratio of the output pulse signal through the difference value between the first voltage value and the second voltage value, so as to realize the accurate control of the neutron tube hot wire power supply process. The whole control process is realized through a hardware circuit, the response speed is high, the output is stable, the stability of the output ion source current is ensured, the situations such as jitter are avoided, the application range of the neutron source is expanded, and wide popularization of the neutron source is facilitated.

The invention discloses a BDD electrode material and a preparation method thereof. The preparation method comprises the following core steps: pretreating the surface of a porous titanium substrate; depositing a nanoscale TiN film layer on the surface of the pretreated porous titanium substrate in advance; depositing a layer of single-walled carbon nanotube network on the TiN thin film layer by using an electrophoretic deposition method; growing a highly-doped BDD layer on the single-walled carbon nanotube network by adopting a plasma enhanced chemical vapor deposition technology; repeating the two steps to form a multi-layer SWCNT / BDD composite structure, and controlling the thickness of the multi-layer SWCNT / BDD composite structure to be 1-50 microns; and finally, depositing a low-doped BDD active layer with the thickness of 1-5 microns by adopting a hot filament chemical vapor deposition (HFCVD) technology. According to the pulse laser assisted preparation process provided by the invention, the femtosecond laser pulse is introduced to replace traditional plasma treatment, so that the process flow is simplified, and the efficiency is improved; according to the technology, the process is simplified, the quality of the TiN film is improved through accurate energy input, and a new way is opened up for further improving the performance of the BDD electrode.

The invention discloses a preparation method of a nano-diamond / graphite composite film electrode with high hydrogen evolution potential and low background current, which comprises the following steps: firstly, preparing the nano-diamond / graphite composite film electrode through hot filament chemical vapor deposition, and then carrying out electrochemical anodic oxidation treatment on the composite film electrode. And finally obtaining the nano-diamond / graphite composite film electrode with high hydrogen evolution potential and low background current. According to the method disclosed by the invention, the content of diamond in the composite film electrode can be increased, and the oxygen element is grafted on the surface of the nano-diamond / graphite composite film electrode, so that the background current of the nano-diamond / graphite composite film electrode is reduced while the hydrogen evolution potential of the nano-diamond / graphite composite film electrode is improved; and a new thought and scheme are provided for design and preparation of the novel nano-diamond film-based composite electrode.

The embodiment of the invention provides a hot wire framework and a device and method for automatically controlling wire distance to deposit diamond. The hot wire framework comprises a plurality of hot wires, a supporting assembly and at least one adjusting mechanism. The supporting assembly comprises a first metal rod, a second metal rod, a plurality of first metal blocks and a plurality of second metal blocks, the first metal rod and the second metal rod are oppositely arranged in the extending direction of the hot wire, the first metal blocks are arranged on the first metal rod in a sliding mode, the second metal blocks are arranged on the second metal rod in a sliding mode, one end of the hot wire is connected with the first metal blocks, and the other end of the hot wire is connected with the second metal blocks. The adjusting mechanism is connected with the first metal block and the second metal block so as to adjust the distance between the adjacent hot wires. The hot wire framework can solve the problem that the grain size is not uniform along with the increase of the deposition time and the thin film thickness.

The invention relates to a method for depositing a high-quality silicon nitride film, which adopts a hot filament chemical vapor deposition technology and comprises the following steps of: preheating a hot filament arranged in a process cavity by adopting small current; the preheated hot wire is heated through large current, ammonia gas is introduced into the process cavity, and the pressure of the process cavity is controlled for reaction; heating the hot wire by adopting large current, introducing ammonia gas, introducing silane into the process cavity, and controlling the pressure of the process cavity for reaction; continuously keeping heating of the hot wire by adopting large current, continuously keeping introduction of ammonia gas, and not controlling the pressure of the process cavity; and cooling the hot wire heated by adopting the large current until the hot wire is heated and buffered by adopting the small current. In addition, the invention also relates to a HoFCVD system. The problem that silane is decomposed prior to ammonia gas is effectively solved, and the quality of the silicon nitride film is improved. The problems that the amorphous silicon film layer is damaged due to the fact that the temperature of the coating substrate of the PECVD equipment is too high and the productivity is insufficient due to the fact that the coating speed of the ALD equipment is low can also be perfectly solved.

The invention relates to a method for passivating the cutting edge of a solar cell, which is used for forming a passive film layer by using hot filament chemical vapor deposition and comprises the following steps of: exposing the cutting edge of the cell and directly facing a hot filament; current is introduced into the hot wire for heating, and H2 is introduced for hydrogen etching; heating is kept, SiH4 is introduced under the first pressure, SiH4 and H2 are introduced while the first pressure is kept, and an a-Si: H film layer is obtained; heating is kept, SiH4 and NH3 are introduced at the same time under the second pressure, a SiNx: H film layer is obtained through deposition on the a-Si: H film layer, and a passivation composite film layer of the cutting edge is formed, or SiH4, NH3, H2 and O2 are introduced at the same time under the second pressure, a SiNxOy: H film layer is obtained through deposition on the a-Si: H film layer, and a passivation composite film layer of the cutting edge is formed. The invention provides a film layer which is low in defect state density, high in passivation performance, excellent in weather resistance, high in optical transmittance and excellent in comprehensive performance, and a film coating technology which is simple in process, high in cost performance and capable of being applied on a large scale.

The invention discloses a laser beam hot wire deposition device for expanding a focal region. The device comprises a laser, a lens group, a deposition working surface and a wire feeding system, the laser is used for emitting laser beams. The lens group is used for converting the laser beam into an expanded focal region laser beam, and the expanded focal region laser beam has the characteristic of transiting from an annular light spot to a continuous solid light spot in space. The deposition working face is used for receiving projection of the expanded focal region laser beam, and solid or annular light spots and a molten pool formed by continuous heating of the light spots are obtained. By adjusting the size of the light spot and the energy distribution mode, deposition morphology with different widths can be obtained. The wire feeding system is used for feeding wires along a preset path, so that the tail ends of the wires are connected with the molten pool in a liquid bridge mode after being preheated by the continuous solid light spots. Compared with the prior art, the expanded focal region laser beam hot wire deposition device has the advantages that the stability of coaxial laser inner wire feeding LMD and the material deposition efficiency are improved, and meanwhile, the temperature gradient of a deposition layer and the material deposition quality are regulated and controlled.

The invention provides a diamond thick film and a preparation method thereof, and the preparation method comprises the following steps: (1) electrifying and heating the surface of a substrate by using a hot filament, introducing a methane and hydrogen mixed gas with the methane volume content of 2-8%, and depositing diamond on the surface of the substrate; (2) after the single deposition thickness of the diamond reaches 50-150 microns, stopping introducing the methane, and maintaining for 0.5-20 hours in a hydrogen atmosphere; (3) introducing a methane and hydrogen mixed gas with the methane volume content of 2-8%, and continuously depositing the diamond; (4) after the single deposition thickness of the diamond reaches 50-150 microns, stopping introducing the methane, and maintaining for 0.5-20 hours in the hydrogen atmosphere; and (5) according to the required thickness of the diamond thick film, the step (3) and the step (4) are repeated, the diamond thick film is obtained, and the thickness is 600-2500 microns. According to the method, the diamond phase content in the diamond thick film is increased, and the mechanical and thermal properties of the diamond thick film are improved.

The utility model belongs to the technical field of coating, and particularly relates to a horizontal type hot wire CVD (chemical vapor deposition) coating device, which comprises a coating chamber, a plurality of heating wires, a plurality of heating wires and a plurality of heating wires, the heating wires are arranged in the coating chamber, and the heating wires comprise a transverse heating wire and a longitudinal heating wire; wherein the transverse hot wires and the longitudinal hot wires are arranged in a laminated manner, and the projections of the transverse hot wires and the longitudinal hot wires on the heating plate are crossed; the horizontal hot filament CVD coating device comprises a coating chamber, a heating plate is arranged on the top surface of the coating chamber, a gas uniformizing chamber is formed between the heating plate and the top surface of the coating chamber, and a plurality of gas uniformizing holes are formed in the heating plate, so that the introduced process gas is more uniform by arranging the gas uniformizing chamber, and meanwhile, the process gas in the gas uniformizing chamber is preheated by arranging the heating plate; and finally, the laminated and crossed hot wire assemblies are arranged, so that a temperature field formed by the hot wire assemblies is more uniform, and the process gas is prevented from crystallizing and dropping slag in the chamber.

The invention discloses a method for depositing a diamond film on the surface of zirconia ceramic and a product and application of the diamond film, and belongs to the technical field of surface treatment.The method comprises the steps that 1, a zirconia ceramic substrate is pretreated; (2) depositing a transition layer on the zirconia ceramic substrate treated in the step (1) through magnetron sputtering, wherein the transition layer is a silicon film, a titanium film or a chromium film; (3) carrying out carbonization heat treatment on the surface of the transition layer through hot filament chemical vapor deposition; and (4) placing the zirconia ceramic substrate treated in the step (3) in an ethanol suspension of nano-diamond, performing ultrasonic oscillation and crystal planting, taking out the zirconia ceramic substrate, drying, and preparing the diamond film by utilizing hot filament chemical vapor deposition. The method is simple, efficient, good in controllability and high in repetition rate, firm connection between the diamond film and the zirconia ceramic can be achieved, the film-substrate matching problem is solved, and the abrasion resistance and corrosion resistance of the zirconia ceramic substrate are improved.

The present invention discloses a nano-diamond / graphene composite vertical lamella film electrode and a preparation method thereof. Through a hot wire chemical vapor deposition system and a microwave plasma vapor deposition system, the relative contents of graphite and diamond on the film surface are effectively regulated to prepare a nano-diamond / graphene composite vertical lamella film electrode with supercapacitor characteristics.

The application discloses a gradient diamond / molybdenum disulfide composite self-lubricating wear-reducing engineering ceramic coating and a preparation method thereof, belongs to the technical field of full ceramic self-lubricating wear-resistant coatings, and the coating is sequentially formed of a multi-stage size progressive diamond coating and a molybdenum disulfide coating from the surface of an engineering ceramic substrate to the outside. The multi-stage size progressive diamond coating comprises a micron diamond coating, a fine-grained diamond coating and a nano diamond coating, and the molybdenum disulfide coating is deposited on the diamond coating. The diamond coating is prepared by using a hot-wire chemical vapor deposition method, and the molybdenum disulfide film covering the diamond coating is prepared by using a direct-current magnetron sputtering method. Under certain conditions, the molybdenum disulfide in the composite coating reacts with the nano diamond and is converted into onion-like carbon, so that the hardness and lubricating performance of the composite coating are improved, and the friction and wear are reduced. The composite coating prepared by using the method has more stable bonding force and adhesion, and the service life of a machine is improved.

The hot filament chemical vapor deposition assembly comprises a hot filament box and a hot filament, the hot filament box forms a first cavity in a surrounding mode, and the hot filament box comprises a first side plate and a second side plate which are oppositely arranged in the first direction; the number of the hot wires is multiple, the multiple hot wires are located in the first cavity and arranged at intervals in the second direction, the second direction is perpendicular to the first direction, the two opposite ends, in the first direction, of each hot wire are connected with the first side plate and the second side plate correspondingly, and each hot wire comprises a spiral section spirally extending in the first direction. The hot filament chemical vapor deposition assembly provided by the invention has the advantages that the thin film deposition rate is not influenced while the hot filament is prevented from deforming and drooping.

The present application relates to a kind of anti-winding plating and anti-pollution's coating carrier plate structure, which is arranged in the process cavity of hot wire chemical vapor deposition, comprising: conveying carrier plate, silicon wafer is installed on it;Spacing plate is positioned between hot wire and conveying carrier plate, one side of spacing plate is towards hot wire, and the other side is towards the side of conveying carrier plate carrying silicon wafer;Wherein, first spacing is provided between spacing plate and conveying carrier plate, and second spacing is provided between spacing plate and hot wire.In addition, the present application also relates to a kind of coating method using the above-mentioned coating carrier plate structure and battery piece coated by the coating method.The present application can avoid winding plating and pollution problem when depositing thin film, and can directly prepare high-quality doped crystalline silicon layer without winding plating and pollution.

A coated tool, such as a rotating, cutting tool, includes a tool body and a multilayer wear protection coating system. The wear protection system coats a functional surface of the tool body that is subject to wear and includes a first undoped diamond layer and a second undoped diamond layer disposed over the first undoped diamond layer. The first undoped diamond layer is electrically conductive and exhibits grain boundary conductivity from delocalized electrons. The second undoped diamond layer is electrically insulating. The first undoped diamond layer is 4-20 microns thick and is made with diamond grains whose size ranges from 4-10 nm. The first and second diamond layers are applied by chemical vapor deposition (CVD) using a hot-wire method. The wear protection system also includes an additional undoped diamond layer that is electrically insulating and is disposed between the functional surface of the tool body and the first diamond layer.

The utility model provides a novel CVD diamond vertical layout hot wire device which comprises two upper electrodes and a lower electrode, the two upper electrodes are vertically arranged in parallel, an upper electrode plate is arranged between the two upper electrodes, the upper electrode plate can slide along the upper electrodes, a lower electrode plate is arranged below the upper electrode plate, and the lower electrode plate can slide along the lower electrode plate. Upper electrodes are arranged at the bottom of the upper electrode plate, lower electrodes are arranged at the bottom of the lower electrode plate, a cross rod is connected between the tops of the two upper electrodes, a plurality of high-temperature springs are connected below the cross rod, a plurality of hooks are arranged on the top surface of the upper electrode plate, and the number of the hooks is consistent with that of the high-temperature springs. According to the novel CVD diamond vertical layout hot wire device, the upper electrode plate capable of moving up and down is arranged, the requirements of hot wires with different lengths can be met, the inner section of the upper electrode plate is approximately small, and when the upper electrode plate works and emits heat, the protruding part of the sliding block can be clamped, so that the upper electrode plate is more stable.

The invention discloses a low-pressure reaction cavity gas inlet device, a deposition reaction cavity and a uniform gas supply method, and relates to the technical field of low-pressure hot filament chemical vapor deposition reaction equipment, and the gas inlet device is provided with a first area distribution cavity and a second area flow equalizing cavity which are connected in series from top to bottom to form a double-cavity sequential pressure stabilizing structure. A top plate of the first area distribution cavity is provided with an air inlet, a diffusion cap with an open upper end and a closed lower end is inserted into the air inlet, and diffusion holes are formed in the circumferential surface of the diffusion cap; and the lower plate of the first area distribution cavity is a flow limiting piece provided with a hole array. The flow dispersing cap cooperates with the flow limiting piece, concentrated inlet air is dispersed and dispersed in the first area, and leading pressure drop is established. And the gas enters the second-area flow equalizing cavity for pressure equalization, and is finally sprayed downwards through the uniform gas outlet surface at the bottom. By constructing a diffusion, pressure stabilization and pressure equalization cascade structure, a distribution mechanism dominated by pressure drop in the device is realized, upstream and downstream process fluctuation is isolated, and uniformity, stability and high repeatability of air flow supplied to a reaction cavity base station area are ensured.

The present invention relates to a method for preparing an oxygen-doped microcrystalline silicon thin film, comprising: texturing a silicon wafer substrate to obtain a double-sided texturized silicon wafer; depositing intrinsic silicon layers on both sides of the texturized silicon wafer to obtain a first structure; placing the first structure in a hot wire chemical vapor deposition device and introducing H2 to hydrogen etch the surface of the silicon wafer; then controlling the pressure in the reaction chamber of the hot wire chemical vapor deposition device while introducing SiH4 and H2 to deposit a seeding layer on the intrinsic silicon layer on the light-facing side of the texturized silicon wafer to obtain a second structure; and simultaneously introducing SiH4, H2, N2O, and PH3 into the reaction chamber to deposit an oxygen-doped microcrystalline silicon layer on the seeding layer of the second structure. Furthermore, the present invention also relates to an apparatus for preparing an oxygen-doped microcrystalline silicon thin film using the above method. The present invention can form an oxygen-doped microcrystalline thin film on the light-facing side of, for example, a heterojunction cell using a HoFCVD device, thereby solving the problem of parasitic absorption on the light-facing side.

The invention relates to the technical field of solar cells, in particular to a boron diffusion method, a solar cell, a preparation method of the solar cell and a photovoltaic module. The invention aims to solve the problem that the photoelectric conversion efficiency of a solar cell is affected due to poor sheet resistance consistency caused by poor diffusion uniformity of the existing boron diffusion method. In order to achieve the purpose, the boron diffusion method comprises the steps that a boron-doped amorphous silicon source layer with the thickness being 3-5 nm is prepared on one face of a silicon wafer through a hot filament chemical vapor deposition method, and oxygen-free boron diffusion treatment is conducted on the silicon wafer deposited with the boron-doped amorphous silicon source layer. And the uniform diffusion of the boron element is facilitated, so that the consistency of resistance after boron diffusion is improved, and the photoelectric conversion efficiency of the solar cell is further improved.

A method of manufacturing a diamond watch crystal wherein the present invention employs multiple techniques to produce the final product. The method of the present invention initiates with a chemical vapor deposition process wherein a high purity graphite is employed as the source substrate. This step further deploys utilization of gases, temperature and an energy source to facilitate formation of a diamond layer on the substrate. The present invention provides alternate energy sources during the chemical vapor deposition such as but not limited to, microwave plasma, direct current plasma, inductively-coupled plasma and hot filament techniques. The method of the present invention further deploys a high pressure high temperature step subsequent the chemical vapor deposition step. These two steps are repeated wherein the initial latter step includes a diamond seed. A final high pressure high temperature step is utilized to remove impurities prior to cutting and polishing.

The invention relates to the technical field of diamond film preparation, in particular to an assembly and device for preparing a diamond film on the surface of a full-ceramic bearing ring, and the assembly comprises a heating component which comprises a plurality of hot wires arranged at equal intervals with the surface of the bearing ring; the rotating component is used for driving the bearing ring to rotate; the base is used for mounting the heating component and the rotating component; the cover body is buckled on the base, and a reaction chamber is defined by the base and the cover body; the heating component and the rotating component are arranged in the reaction chamber; an air inlet and an air outlet are further formed in the cover body, and the air inlet is used for being connected with an external air supply device; the device comprises the chemical vapor deposition assembly, a gas supply device, a motor, a power supply system and a cooling water channel. The hot wires and the surface of the bearing ring are arranged at equal intervals, and the bearing ring is driven to rotate at a constant speed through the rotating component, so that all surface areas are subjected to the same thermal radiation and gas decomposition environment, and the deposition efficiency and the film layer quality are improved.

The invention discloses a method for preparing a lubricating protective coating on the surface of a silicon carbide substrate, and belongs to the technical field of composite coating preparation, and the method comprises the following steps: (1) carrying out cleaning and drying pretreatment on the silicon carbide substrate, or sequentially carrying out cleaning and drying pretreatment and surface texturing treatment on the silicon carbide substrate; (2) carrying out surface roughening treatment on the silicon carbide substrate treated in the step (1), then putting the silicon carbide substrate into suspension containing nano-diamond, carrying out ultrasonic oscillation and crystal planting, taking out the silicon carbide substrate, drying the silicon carbide substrate, and preparing a diamond coating by utilizing hot filament chemical vapor deposition; and (3) taking boron nitride as a raw material, and compounding the boron nitride and the diamond coating on the silicon carbide substrate treated in the step (2) by utilizing a spin-coating method or a magnetron sputtering method to obtain the lubricating protective coating. According to the method, the diamond / boron nitride composite coating is used for achieving surface lubricating protection of the silicon carbide substrate, implementation is easy, and the lubricating effect is good.

The invention discloses a method for preparing large-area diamond at high temperature by an HFCVD (High Frequency Chemical Vapor Deposition) method. The method comprises the following steps: producing the diamond through a hot filament chemical vapor deposition device; the diameter of the produced diamond is more than or equal to 200mm; the hot filament chemical vapor deposition device is provided with a deposition space, and a hot filament assembly, a deposition base station and a temperature compensation device are arranged in the deposition space. The hot wire assembly comprises a plurality of hot wires which are arranged in parallel; the deposition base station comprises a substrate and a cooling interlayer mechanism; the substrate is placed on the upper surface of the cooling interlayer; the temperature compensation device comprises a substrate compensation device; the hot wire distance D between the parallel hot wires is adjusted, and D is 4-12 mm; adjusting a substrate distance H between the hot filament plane and the substrate through a first formula according to the hot filament distance D; after cooling is completed, hydrogen in the furnace is discharged, the diamond film layer is taken down from the surface of the deposition base body, and diamond is obtained; and the diamond with large area, high quality and few impurities and defects is prepared.

The application discloses a kind of based on multi-zone coordinated thermal field regulation and control large-size BDD electrode integrated preparation device and method, belong to CVD equipment technical field.The device includes reaction chamber, liftable base, multi-zone independent controllable hot wire system, composite temperature monitoring system and intelligent control system.It is in that hot wire system is divided into multiple independent temperature control subareas, and temperature measurement mode combining contact and non-contact is used, and the temperature of multiple regions on substrate surface is obtained in real time by control system, each subarea hot wire power is dynamically and independently adjusted by closed-loop control, accurate, active coordinated regulation and control of surface temperature field of large-size substrate is realized, and "edge effect" is effectively inhibited.The method can automatically prepare large-size BDD electrode, and the electrode has excellent in-plane uniformity in film thickness, doping concentration and oxygen evolution potential and other key performances.The application solves the problem of uniform preparation of large-size high-performance BDD electrode, and provides a reliable technical foundation for industrial mass production.

The invention relates to the technical field of preparation of silicon carbide coatings, in particular to a method for preparing a silicon carbide coating on a hard alloy substrate. The method comprises the following steps that firstly, a hard alloy substrate is pretreated, then the pretreated substrate is placed on a clamp in hot filament chemical vapor deposition equipment, then tetramethylsilane and hydrogen are introduced into a reaction cavity, precursor cracking is excited through a hot filament, and the hard alloy substrate is obtained. The compact and uniform silicon carbide coating is obtained on the surface of the hard alloy substrate, and meanwhile the hard alloy substrate with more excellent performance is provided. According to the method, the applicable substrate of the preparation technology of the silicon carbide coating is widened, the application range of the silicon carbide coating is expanded, and the silicon carbide coating prepared on the hard alloy substrate has high purity, good crystal quality and excellent film-substrate adhesion strength; and the wear resistance and the service life of the cutter can be obviously improved when applied to the surface of the hard alloy cutter.

A specific embodiment of the present invention provides a hydrophilic coating, a preparation method and a device. The hydrophilic coating is formed by hot wire chemical vapor deposition of silicone monomers on the surface of a substrate in an atmosphere with oxygen. The hydrophilic coating has excellent hydrophilic properties, a water contact angle of less than 10°, and excellent hydrophilic retention in a high humidity environment.