阅读说明：本技术 一种大粒度多层钎焊金刚石砂轮电解氧化膜的成膜性能调控方法 (Film forming property regulation and control method for large-particle-size multilayer brazed diamond grinding wheel electrolytic oxide film ) 是由 伍俏平 阳慧 欧阳志勇 宋琨 段良辉 于 2019-09-24 设计创作，主要内容包括：本发明公开一种大粒度多层钎焊金刚石砂轮电解氧化膜的成膜性能调控方法。本发明通过采用电解液喷射装置精准控制在砂轮磨粒锋利阶段喷射含碳纳米管电解液和含碳微球电解液,表面能生成一层粘附力大、且具有自润滑功能的复合氧化膜；而在砂轮磨粒磨损阶段只喷射电解能力更强的含碳纳米管电解液,并提高电解电压、电解时间等电解参数,使氧化膜厚度快速增大,磨损磨粒及时脱落,有效保证大粒度多层钎焊砂轮的锋利性和容屑空间。本发明有效解决了大粒度多层钎焊金刚石砂轮修整困难的问题,也能实现大粒度多层钎焊金刚石砂轮在整个磨削过程中均能达到高效精密加工的效果。(the invention discloses a film forming property regulating method of a large-granularity multilayer brazing diamond grinding wheel electrolytic oxide film. According to the invention, the electrolyte injection device is adopted to accurately control the injection of the carbon-containing nanotube electrolyte and the carbon-containing microsphere electrolyte at the abrasive particle sharp stage of the grinding wheel, so that a layer of composite oxide film with high adhesive force and a self-lubricating function can be generated on the surface; and only the carbon nanotube-containing electrolyte with stronger electrolytic capacity is sprayed in the abrasive particle abrasion stage of the grinding wheel, electrolytic parameters such as electrolytic voltage and electrolytic time are improved, the thickness of the oxide film is rapidly increased, the abraded abrasive particles fall off in time, and the sharpness and chip containing space of the large-particle-size multi-layer brazing grinding wheel are effectively ensured. The method effectively solves the problem that the large-granularity multilayer brazed diamond grinding wheel is difficult to repair, and can also achieve the effect that the large-granularity multilayer brazed diamond grinding wheel can achieve efficient and precise machining in the whole grinding process.)

1. a film forming property regulation and control method of a large-granularity multilayer brazing diamond grinding wheel electrolytic oxide film is characterized in that an electrolyte injection device is used for alternately injecting a carbon nanotube-containing electrolyte and a carbon microsphere-containing electrolyte to the large-granularity multilayer brazing grinding wheel in a grinding wheel sharp stage, so that a composite oxide film with a carbon nanotube-containing inner layer, strong adhesion and carbon microsphere-containing outer layer and self-lubricating property can be generated on the surface of the large-granularity multilayer brazing grinding wheel; when the abrasive particles of the grinding wheel enter the abrasion stage, only the carbon-containing nanotube electrolyte is sprayed, the electrolytic voltage and the spraying flow speed are increased, the generation speed and the thickness of an oxide film are improved, the abrasive particles are ensured to fall off in time, and the sharpness and the chip containing space of the grinding wheel are improved.

2. The method for regulating and controlling the film forming property of the large-granularity multilayer brazed diamond grinding wheel electrolytic oxide film according to claim 1, wherein the electrolytic injection device comprises an ELID pulse power supply, a first water pump, a first electromagnetic valve, a cathode binding post, a cathode block, a second electromagnetic valve, a second water pump, a PLC (programmable logic controller), a first electrolytic tank, a force measuring sensor, a workpiece, a brazed grinding wheel and a second electrolytic tank, wherein the anode of the ELID pulse power supply is connected with the brazed grinding wheel, the cathode is connected with the cathode block through the cathode binding post, the first water pump and the first electromagnetic valve are connected with the first electrolytic tank and communicated with an injection port on the cathode block to realize the injection of the brazed grinding wheel, the second water pump and the second electromagnetic valve are connected with the second electrolytic tank and communicated with the injection port on the cathode block to realize the injection of the brazed grinding wheel, and the first electromagnetic valve and the second electromagnetic valve are simultaneously connected with the, the workpiece is connected with a force transducer.

3. The large-granularity multilayer brazing diamond grinding wheel electrolytic oxide film forming performance regulating method as claimed in claim 1, wherein the carbon nanotube-containing electrolyte comprises the following components in percentage by mass: 0.5-0.6% of sodium chloride, 0.3-0.4% of triethanolamine, 0.3-0.5% of polydimethylsiloxane organic defoaming agent, 0.5-0.8% of alkyl sulfonate anionic surfactant, 0.15-0.2% of carbon nano tube and the balance of water.

4. The method for regulating and controlling the film forming property of the large-granularity multilayer brazed diamond grinding wheel electrolytic oxide film according to claim 1, wherein the carbon-containing microsphere electrolyte comprises the following components in percentage by mass: 0.2-0.3% of sodium chloride, 3-4% of sodium nitrate, 0.3-0.4% of triethanolamine, 0.3-0.4% of polydimethylsiloxane organic defoaming agent, 0.3-0.4% of alkyl sulfonate anionic surfactant, 0.08-0.1% of carbon microsphere and the balance of water.

5. The large-granularity multilayer brazing diamond grinding wheel electrolytic oxide film forming performance regulating method according to claim 1, wherein the electrolytic process parameters of the grinding wheel abrasive grain sharpening stage are as follows: when the carbon nanotube-containing electrolyte is sprayed, the electrolytic voltage is 60-70V, the duty ratio is 50-60%, the flow rate of the electrolyte is 2-3L/min, the spraying time is 3-5 min, when the carbon microsphere-containing electrolyte is sprayed, the electrolytic voltage is 60-70V, the duty ratio is 50-60%, the flow rate of the electrolyte is 0.5-1L/min, and the spraying time is 5-8 min; the electrolysis technological parameters of the abrasion stage of the abrasive particles of the grinding wheel are as follows: the electrolytic voltage is 100-120V, the duty ratio is 70-80%, the flow rate of the electrolyte is 5-6L/min, and the spraying time is 15-18 min.

6. the method for regulating and controlling the film forming property of the electrolytic oxide film of the large-particle-size multilayer brazing diamond grinding wheel according to claim 1, is characterized by comprising the following steps of:

(1) Respectively preparing carbon nanotube-containing electrolyte A and carbon microsphere-containing electrolyte B, wherein the electrolyte A comprises the following components in percentage by mass: 0.5-0.6% of sodium chloride, 0.3-0.4% of triethanolamine, 0.3-0.5% of polydimethylsiloxane organic defoaming agent, 0.5-0.8% of alkyl sulfonate anionic surfactant, 0.15-0.2% of carbon nano tube and the balance of water; the electrolyte B comprises the following components in percentage by mass: 0.2-0.3% of sodium chloride, 3-4% of sodium nitrate, 0.3-0.4% of triethanolamine, 0.3-0.4% of polydimethylsiloxane organic defoaming agent, 0.3-0.4% of alkyl sulfonate anionic surfactant, 0.08-0.1% of carbon microsphere and the balance of water;

(2) At the initial stage of electrolytic dressing and grinding, an electrolytic spraying device is adopted to alternately spray carbon-containing nanotube electrolyte and carbon-containing microsphere electrolyte, the adopted electrolytic spraying device comprises an ELID pulse power supply, a first water pump, a first electromagnetic valve, a cathode binding post, a cathode block, a second electromagnetic valve, a second water pump, a PLC (programmable logic controller), a first electrolytic tank, a force measuring sensor, a workpiece, a brazing grinding wheel and a second electrolytic tank, the anode of the ELID pulse power supply is connected with the brazing grinding wheel, the cathode is connected with the cathode block through the cathode binding post, the first water pump and the first electromagnetic valve are connected with the first electrolytic tank, and communicated with a jet orifice on the cathode block to realize the jet of the brazing grinding wheel, a second water pump and a second electromagnetic valve are connected with a second electrolytic tank, the first electromagnetic valve and the second electromagnetic valve are simultaneously connected with a PLC controller, and the workpiece is connected with a force transducer;

in the electrolytic finishing process, firstly, a PLC controller starts a first water pump to spray the carbon-containing nanotube electrolyte A in a first electrolytic tank, and controls a first electromagnetic valve to adjust the flow rate of the electrolyte to be 2-3L/min, and the electrolytic parameters of an ELID pulse power supply are as follows: the electrolytic voltage is 60-70V, and the duty ratio is 50-60%; detecting electrolytic grinding force in real time by using a force transducer, feeding back a grinding force value to a PLC (programmable logic controller), presetting a grinding force threshold value by the PLC, controlling and spraying carbon nanotube-containing electrolyte A by the PLC when the grinding force is smaller than the threshold value, wherein the spraying time is 3-5 minutes, then closing a first electromagnetic valve for controlling the carbon nanotube-containing electrolyte A, simultaneously starting a second water pump for spraying carbon microsphere-containing electrolyte B in a second electrolytic tank, the spraying time is 5-8 minutes, and controlling a second electromagnetic valve to adjust the flow rate of the electrolyte to be 0.5-1 liter/minute, and generating a composite oxide film with a carbon nanotube-containing inner layer, strong adhesiveness, a carbon microsphere-containing outer layer and self-lubricating property on the surface of the large-particle-size multilayer brazing grinding wheel;

(3) The grinding wheel abrasive particles gradually enter a wear stage, when the grinding force detected by the force cell sensor in real time is greater than a set threshold value, the second electromagnetic valve for controlling the carbon-containing microsphere electrolyte B is closed, the first electromagnetic valve for controlling the carbon-containing nanotube electrolyte A is rapidly started, the flow rate of the electrolyte is adjusted to be 5-6L/min, and the electrolysis parameters are adjusted to be: the electrolytic voltage is 100-120V, the duty ratio is 70-80%, and the spraying time is 15-18 minutes; thereby improving the film forming speed and thickness, generating a layer of thick and loose oxide film on the surface of the large-granularity multi-layer brazing grinding wheel and ensuring that the wear abrasive particles smoothly fall off.

Technical Field

the invention relates to an electrolytic trimming film forming method in the field of efficient precision machining, in particular to a film forming performance regulating method for an electrolytic oxidation film of a large-granularity multilayer brazing diamond grinding wheel.

Background

At present, the fine-grained diamond grinding wheel is widely applied to the precise/ultra-precise grinding process of difficult-to-machine materials, and particularly applied to the precise grinding occasion of online electrolytic finishing with high requirement on the quality of the machined surface and stable requirement on the machining process. The grain diameter of the abrasive grain of the fine-grained grinding wheel is usually in the micron or submicron grade, so that the processing precision can be effectively ensured, but in the grinding process, the processing efficiency is lower because the grain diameter of the abrasive grain is small and the material removing amount of a single abrasive grain is small; and the abrasive resistance of the fine-grained diamond abrasive particles is limited, and the abrasive particles are easy to wear so as to influence the overall performance and the service life of the grinding wheel.

the grain diameter of the abrasive grains of the large-grain-size multilayer brazing diamond grinding wheel is thick (generally, one hundred micrometers to hundreds of micrometers), the amount of material removed by the abrasive grains in unit time is large, and the processing efficiency of the grinding wheel is high; meanwhile, the surface scratches caused by the large-particle-size abrasive particles in the grinding process are deeper, so that the quality of the processed surface is poor; particularly when the abrasive grains are worn seriously, the dull abrasive grains crush and scrape the processed surface, causing serious deterioration of the quality of the processed surface. Particularly, in the case of a brazing grinding wheel, the abrasive grains have a large holding force, and are difficult to fall off after being worn, so that the grinding force and the grinding temperature are both increased sharply, which undoubtedly seriously affects the usability of the machined parts.

if the high efficiency and the long service life of large-particle-size abrasive particles are fully utilized, the large-particle-size multilayer brazing diamond grinding wheel is expected to have good self-lubricating performance when the abrasive particles are sharp, so that scraping and plowing of the large-particle-size abrasive particles on a machined surface are reduced, and the quality of the machined surface of the large-particle-size brazing diamond grinding wheel is improved; when the abrasive particles are seriously abraded, the abraded abrasive particles on the working surface of the grinding wheel can be ensured to fall off in time, the sharpness and the chip containing space of the grinding wheel are effectively ensured, and the application of the large-granularity multilayer brazing diamond grinding wheel in the high-efficiency precision of difficult-to-process materials is greatly facilitated.

at present, an electrolytic dressing technology is applied to dressing of a metal bond grinding wheel, the technology mainly adopts an anode dissolution effect in an electrochemical reaction to carry out electrolytic corrosion on a metal bond on the surface layer of the grinding wheel to generate an insulating oxide film, the oxide film changes the holding state of abrasive particles, the abrasive particles are changed from high-strength holding of a grinding wheel base material to the embedding effect of loosening the oxide film, and the abrasive particles are easy to fall off in the grinding process; on the other hand, the oxide film avoids direct contact between the grinding wheel binder and the workpiece in the grinding process, and reduces the vibration and impact of the grinding wheel on the workpiece. However, in the conventional electrolytic trimming process of the electrolyte, the generated thickness of the oxide film is relatively thin, generally several micrometers to tens of micrometers, which can only meet the requirements of a fine-grained diamond grinding wheel, and greatly limits the application of the oxide film in the electrolytic trimming of a large-grained multilayer brazing grinding wheel. The method is characterized in that the grain size of the abrasive grains of the large-grain-size multilayer brazing grinding wheel is large, the depth of the abrasive grains embedded in a grinding wheel base material is large, the bottoms of the abrasive grains on the working surface of the grinding wheel are still densified and held by brazing filler metal in the common electrolysis process, the abrasive grains cannot fall off in time, and the quality of the processed surface is continuously reduced due to the existence of the abrasive grains. Therefore, how to improve the electrolytic capacity of the electrolyte in the electrolytic trimming process, increase the film forming speed and the film forming thickness of the electrolytic oxide film, regulate and control the film forming performance of the electrolytic oxide film under different conditions of abrasive particle sharpness and abrasion in real time, realize the efficient and precise processing of the large-granularity multilayer brazing diamond grinding wheel in the whole grinding process and have very important significance for the application of the large-granularity multilayer brazing diamond grinding wheel in the electrolytic trimming.

Disclosure of Invention

The invention aims to provide a film forming property regulating method of an electrolytic oxide film of a large-granularity multilayer brazing diamond grinding wheel. The method comprises the following steps of firstly preparing two different electrolytes: one electrolyte contains carbon nanotubes and the other electrolyte contains carbon microspheres. The electrolytic spraying device is utilized to accurately control the initial grinding stage of the electrolytic grinding wheel, the carbon nanotube-containing electrolyte is firstly sprayed for a short time, the carbon nanotube has good conductivity, is adsorbed in an oxide film of the anode brazing grinding wheel in the electrolytic process, has large length-diameter ratio and a spiral winding structure, is connected with the oxide film in a net shape, and can obviously improve the adsorption strength of the oxide film; and then, spraying carbon-containing microsphere electrolyte to distribute carbon microspheres in the outer layer oxide film, so that the self-lubricating property of the grinding wheel is improved, and the grinding surface quality of the large-granularity multilayer brazing grinding wheel is improved. With the progress of grinding, the abrasive wear gradually becomes serious, which is reflected by the rapid increase of grinding force and the unstable grinding force, which indicates that the abrasive wear of the grinding wheel is serious and the abrasive wear needs to be timely removed. Considering that the carbon nano tube has better electrolytic capacity than the carbon microsphere, the spiral curling structural characteristics of the carbon nano tube enable the carbon nano tube to be better combined with the oxide film, at the moment, the valve is closed by the PLC controller to stop spraying the carbon-containing microsphere electrolyte, the carbon-containing nano tube electrolyte is sprayed instead, the electrolytic voltage is increased, the electrolytic time is prolonged, the film forming speed of the electrolytic oxide film and the thickness of the oxide film are effectively improved, the tightly held state of the abrasive particles in the grinding wheel base material is changed into the state of being embedded by the loose oxide film, the abraded abrasive particles can fall off in time, and the efficient and precise grinding performance of the large-particle-size multilayer brazed diamond grinding wheel is.

The technical scheme adopted by the invention is as follows:

a film forming property regulation method of an electrolytic oxide film of a large-particle-size multilayer brazing diamond grinding wheel comprises the following steps:

₂(1) Respectively preparing a carbon nanotube-containing electrolyte (marked as an electrolyte A) and a carbon microsphere-containing electrolyte (marked as an electrolyte B), wherein the electrolyte A comprises the following components in percentage by mass: 0.5-0.6% of sodium chloride, 0.3-0.4% of triethanolamine, 0.3-0.5% of polydimethylsiloxane organic defoaming agent, 0.5-0.8% of alkyl sulfonate anionic surfactant, 0.15-0.2% of carbon nano tube and the balance of water; the sodium chloride is used for electrolytically corroding the TiO2 passivation layer on the surface of the brazing grinding wheel, the content of the sodium chloride is relatively high, mainly because the passivation layer is uniform and compact, and at the moment, the concentration of an electric corrosion substance is required to be high, so that the pitting corrosion capability is high; triethanolamine is used as an organic antirust agent for preventing electrolyte from corroding a machine tool, and belongs to a green environment-friendly antirust agent; the polydimethylsiloxane organic defoaming agent is a defoaming agent, mainly plays a role in defoaming and breaking foam in the electrolytic process, prevents an oxide film from generating a hole phenomenon, and has the characteristics of good thermal stability, strong defoaming capability, no toxicity and the like; the alkyl sulfonate anionic surfactant is used as a dispersing agent to prevent the carbon nano tube from agglomerating in the electrolyte, and has the characteristics of good water solubility, strong surface activity and the like; the carbon nano tube is used as an electrolyte additive and is used for improving the electrolytic capacity of the electrolyte;

the electrolyte B comprises the following components in percentage by mass: 0.2-0.3% of sodium chloride, 3-4% of sodium nitrate, 0.3-0.4% of triethanolamine, 0.3-0.4% of polydimethylsiloxane organic defoaming agent, 0.3-0.4% of alkyl sulfonate anionic surfactant, 0.08-0.1% of carbon microsphere and the balance of water; sodium chloride is taken as a main electrolytic corrosion component, and the content of the sodium chloride can be properly reduced because most of the passivation layer on the brazing grinding wheel at the post-electrolysis stage is electrolyzed and corroded; however, since an insulating oxide film with a certain thickness is generated in the earlier stage of electrolysis, an auxiliary electrolyte sodium nitrate needs to be properly added to improve the conductivity of the electrolyte; triethanolamine is used as an organic antirust agent for preventing the corrosion of electrolyte to a machine tool; polydimethylsiloxane is used as an organic defoaming agent, so that looseness and easy falling caused by excessive oxide film holes are prevented; the carbon microspheres are used a electrolyte additives and are used for improving the self-lubricating property of the electrolytic oxide film;

(2) At the initial stage of electrolytic dressing and grinding, an electrolytic spraying device is adopted to alternately spray carbon-containing nanotube electrolyte and carbon-containing microsphere electrolyte, the adopted electrolytic spraying device comprises an ELID pulse power supply, a first water pump, a first electromagnetic valve, a cathode binding post, a cathode block, a second electromagnetic valve, a second water pump, a PLC (programmable logic controller), a first electrolytic tank, a force measuring sensor, a workpiece, a brazing grinding wheel and a second electrolytic tank, the anode of the ELID pulse power supply is connected with the brazing grinding wheel, the cathode is connected with the cathode block through the cathode binding post, the first water pump and the first electromagnetic valve are connected with the first electrolytic tank, and communicated with a jet orifice on the cathode block to realize the jet of the brazing grinding wheel, a second water pump and a second electromagnetic valve are connected with a second electrolytic tank, the first electromagnetic valve and the second electromagnetic valve are simultaneously connected with a PLC controller, and the workpiece is connected with a force transducer;

In the electrolytic finishing process, firstly, a PLC controller starts a first water pump to spray the carbon-containing nanotube electrolyte A in a first electrolytic tank, and controls a first electromagnetic valve to adjust the flow rate of the electrolyte to be 2-3L/min, and the electrolytic parameters of an ELID pulse power supply are as follows: the electrolytic voltage is 60-70V, and the duty ratio is 50-60%; the electrolytic grinding force is detected in real time by using a force transducer, the numerical value of the grinding force is fed back to a PLC (programmable logic controller), the PLC is preset with a grinding force threshold value, when the grinding force is smaller than the threshold value, the PLC controls the injection of the carbon nanotube-containing electrolyte A for 3-5 minutes, then a first electromagnetic valve for controlling the carbon nanotube-containing electrolyte A is closed, a second water pump is started to inject the carbon microsphere-containing electrolyte B in a second electrolytic tank for 5-8 minutes, and the second electromagnetic valve is controlled to adjust the flow rate of the electrolyte to be 0.5-1 liter/minute. The oxidation film is similar to a polishing pad which is not easy to fall off, the polishing effect is stably exerted, scratches and damages formed by scraping of large-particle-size abrasive particles are reduced, and the quality of a processed surface is ensured;

(3) along with the grinding, the grit is worn and torn seriously gradually, and grinding force also lasts the increase, and when force cell real-time detection's grinding force was greater than and sets up the grinding force threshold value, the second solenoid valve of control carbonous microballon electrolyte B was closed to quick start control carbonous nanotube electrolyte A's first solenoid valve, the electrolyte velocity of flow adjustment was 5 ~ 6 liters/minute, and the adjustment electrolysis parameter is: the electrolytic voltage is 100-120V, the duty ratio is 70-80%, and the spraying time is 15-18 minutes; at the moment, the electrolysis parameters and the flow rate of the electrolyte are increased, the intensity of the electrolysis reaction can be improved, and the film forming speed and thickness are improved, so that a layer of thick and loose oxide film is generated on the surface of the large-granularity multi-layer brazing grinding wheel. The abrasive particles are embedded with small acting force and can easily fall off smoothly in the processing process, thereby keeping the sharpness and the chip containing space of the grinding wheel and improving the processing performance.

It should be noted that the grinding force threshold is determined as follows: at the initial stage of grinding, the grinding force signal is more steady, when wearing and tearing appear, then the obvious undulant of grinding force signal characteristic can appear, consequently, it is obvious that the grinding force signal characteristic appears undulant in the grinding process through surveying, and the critical numerical value of grinding force when numerical value sharply increases to utilize three-dimensional video microscope to observe emery wheel surface grit wearing and tearing condition this moment, appear blocking and most grit with the emery wheel surface and appear the broken geomorphology characteristic of bold as the auxiliary basis, confirm the wearing and tearing condition jointly. And repeating the grinding experiment for 3-5 times, and taking the average value as a grinding force reference value F2. The safety coefficient is 0.8-0.9 in consideration of the influence of errors, and the purpose is to avoid the influence on the processing performance caused by the fact that the worn abrasive particles cannot be electrolyzed and fall off timely due to the fact that the set threshold value is large under the influence of grinding errors. Therefore, 0.8-0.9F 2 is set as the grinding force threshold F1.

Compared with the prior art, the invention has the beneficial effects that:

According to the invention, the carbon nanotube-containing electrolyte is sprayed at the early grinding stage of the grinding wheel through accurate control, the carbon nanotube has a large length-diameter ratio, and is connected with the oxide film in a net shape due to a spiral winding structure, so that the adsorption strength of the oxide film is improved; then carbon-containing microsphere electrolyte is sprayed, so that carbon microspheres are uniformly distributed in the outer layer oxide film, the self-lubricating property of the grinding wheel is improved, and the grinding surface quality of the large-granularity multilayer brazing grinding wheel is improved. When the abrasive particles of the grinding wheel are seriously worn, only the carbon nanotube-containing electrolyte with stronger electrolytic capacity is sprayed, the electrolytic voltage is increased, the electrolytic time is prolonged, the film forming speed of an electrolytic oxide film is increased, the thickness of the oxide film is increased, the worn abrasive particles smoothly fall off, and the sharp abrasive particles on the lower layer are timely updated to continuously exert the cutting performance. Therefore, the large-granularity multi-layer brazing diamond grinding wheel can effectively realize stable and efficient precise grinding processing in the whole grinding process, and has a wide application prospect in efficient precise processing of difficult-to-process materials such as engineering ceramics and the like.

Drawings

FIG. 1 is a schematic view showing the structure of an electrolytic spraying device used in the present invention.

FIG. 2 is a schematic view of the electrolytic oxide film structure when the grinding wheel abrasive grains are sharp.

FIG. 3 is a schematic view of the structure of the electrolytic oxide film when the abrasive grains are worn seriously.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings, but the present invention is not limited thereto.

As shown in figure 1, the electrolysis spray device adopted by the invention comprises an ELID pulse power supply 1, a first water pump 2, a first electromagnetic valve 3, a cathode binding post 4, a cathode block 5, a second electromagnetic valve 6, a second water pump 7, a PLC 8, a first electrolytic tank 9, a force measuring sensor 10, a workpiece 11, a brazing grinding wheel 12 and a second electrolytic tank 13, wherein the anode of the ELID pulse power supply 1 is connected with the brazing grinding wheel 12, the cathode is connected with the cathode block 5 through the cathode binding post 4, the first water pump 2 and the first electromagnetic valve 3 are connected with the first electrolytic tank 9, and communicated with a jet orifice on the cathode block 5 to realize the jet of the brazing grinding wheel 12, a second water pump 7 and a second electromagnetic valve 6 are connected with a second electrolytic bath 13, and the spraying ports on the cathode block 5 are communicated to realize the spraying of the brazing grinding wheel 12, the first electromagnetic valve 3 and the second electromagnetic valve 6 are simultaneously connected with the PLC 8, and the workpiece 11 is connected with the force measuring sensor 10.

The invention discloses a film-forming property regulating method of an electrolytic oxide film of a large-particle-size multilayer brazing diamond grinding wheel, which comprises the following steps of:

(1) Respectively preparing a carbon nanotube-containing electrolyte (marked as an electrolyte A) and a carbon microsphere-containing electrolyte (marked as an electrolyte B), wherein the electrolyte A comprises the following components in percentage by mass: 0.5-0.6% of sodium chloride, 0.3-0.4% of triethanolamine, 0.3-0.5% of polydimethylsiloxane organic defoaming agent, 0.5-0.8% of alkyl sulfonate anionic surfactant, 0.15-0.2% of carbon nano tube and the balance of water; the sodium chloride is used as a main electrolytic corrosion component and is used for electrolytically corroding a TiO2 passivation layer on the surface of the brazing grinding wheel, the content of the sodium chloride is relatively high, mainly because the passivation layer is uniform and compact, and at the moment, the concentration of an electrolytic corrosion substance is required to be high, so that the corrosion resistance is high; triethanolamine is used as an organic antirust agent for preventing electrolyte from corroding a machine tool, and belongs to a green environment-friendly antirust agent; the polydimethylsiloxane organic defoaming agent is a defoaming agent, mainly plays a role in defoaming and breaking foam in the electrolytic process, prevents an oxide film from generating a hole phenomenon, and has the characteristics of good thermal stability, strong defoaming capability, no toxicity and the like; the alkyl sulfonate anionic surfactant is used as a dispersing agent to prevent the carbon nano tube from agglomerating in the electrolyte, and has the characteristics of good water solubility, strong surface activity and the like; the carbon nano tube is used as an electrolyte additive and is used for improving the electrolytic capacity of the electrolyte;

the electrolyte B comprises the following components in percentage by mass: 0.2-0.3% of sodium chloride, 3-4% of sodium nitrate, 0.3-0.4% of triethanolamine, 0.3-0.4% of polydimethylsiloxane organic defoaming agent, 0.3-0.4% of alkyl sulfonate anionic surfactant, 0.08-0.1% of carbon microsphere and the balance of water;

Sodium chloride is taken as a main electrolytic corrosion component, and the content of the sodium chloride can be properly reduced because most of the passivation layer on the brazing grinding wheel at the post-electrolysis stage is electrolyzed and corroded; however, since an insulating oxide film with a certain thickness is generated in the earlier stage of electrolysis, an auxiliary electrolyte sodium nitrate needs to be properly added to improve the conductivity of the electrolyte; triethanolamine is used as an organic antirust agent for preventing the corrosion of electrolyte to a machine tool; polydimethylsiloxane is used as an organic defoaming agent, so that looseness and easy falling caused by excessive oxide film holes are prevented; the carbon microspheres are used as electrolyte additives and are used for improving the self-lubricating property of the electrolytic oxide film;

(2) at the initial stage of electrolytic trimming and grinding, the electrolytic spraying device is adopted to alternately spray the carbon-containing nanotube electrolyte and the carbon-containing microsphere electrolyte, during the electrolytic trimming process, the PLC controller 8 starts the first water pump 2 to spray the carbon-containing nanotube electrolyte A in the first electrolytic cell 9, and controls the first electromagnetic valve 3 to adjust the flow rate of the electrolyte to be 2-3L/min, and the electrolytic parameters of the ELID pulse power supply 1 are as follows: electrolytic voltage is 60-70V, duty ratio: 50% -60%; the electrolytic grinding force is detected in real time by using a force sensor 10, the grinding force value is fed back to a PLC (programmable logic controller) 8, the PLC 8 is preset with a grinding force threshold value, when the grinding force is smaller than the threshold value, the PLC 8 controls the spraying time of the carbon nanotube-containing electrolyte A to be sprayed for 3-5 minutes, then a first electromagnetic valve 3 controlling the carbon nanotube-containing electrolyte A is closed, a second water pump 7 is started to spray the carbon microsphere-containing electrolyte B in a second electrolytic tank 13 for 5-8 minutes, and a second electromagnetic valve 6 is controlled to adjust the flow rate of the electrolyte to be 0.5-1 liter/minute, so that a composite oxide film with a carbon nanotube in the inner layer and high adhesiveness and a carbon microsphere in the outer layer and self-lubricating performance can be generated on the surface of the large-particle-size multilayer brazing grinding wheel as shown in figure 2 (wherein 101-carbon microsphere, 102-sharp abrasive particles, 103-carbon nanotube, 104-oxide film and 105- A grinding wheel base material; 106-underlying sharp abrasive particles). The oxidation film is similar to a polishing pad which is not easy to fall off, the polishing effect is stably exerted, scratches and damages formed by scraping of large-particle-size abrasive particles are reduced, and the quality of a processed surface is ensured;

(3) Along with the grinding, the grit is worn and torn seriously gradually, and grinding force also lasts the increase, and when force cell sensor 10 real-time detection's grinding force was greater than and sets up the threshold value, the second solenoid valve 6 of control carbonous microballon electrolyte B was closed to quick start controls carbonous nanotube electrolyte A's first solenoid valve 3, and the electrolyte velocity of flow adjustment is 5 ~ 6 liters/minute, and the adjustment electrolysis parameter is: electrolytic voltage is 100-120V, duty ratio is 70-80%, and electrolytic time is as follows: 15-18 minutes; at this time, the flow rate of the electrolyte is increased, the injection amount of the electrolyte can be increased, the intensity of electrolytic reaction is improved, and the film forming speed and thickness are increased, so that a layer of thicker and loose oxide film is generated on the surface of the large-particle-size multilayer brazing grinding wheel as shown in FIG. 3 (wherein 201 is wear abrasive particles; 202 is carbon nano tubes; 203 is oxide film; 204 is sharp abrasive particles; 205 is grinding wheel base material). The abrasive particles are embedded with small acting force and can easily fall off smoothly in the processing process, thereby keeping the sharpness and the chip containing space of the grinding wheel and improving the processing performance.