Surface antioxidant treatment method of low-demagnetization-rate neodymium iron boron permanent magnet powder
Technical Field
The invention relates to the technical field of surface treatment processes of magnetic powder, in particular to a surface oxidation resistance treatment method of neodymium iron boron permanent magnet powder with a low demagnetization rate.
Background
With the rapid development of high-tech industry, the NdFeB permanent magnet powder is widely applied to the fields of aviation, aerospace, navigation, automobiles, various precision instruments, small and medium-sized, miniature high-efficiency motors, computers, IT technical equipment, office automation equipment, numerous household appliances and the like, and is continuously expanding.
The Nd-Fe-B permanent magnetic powder has the characteristics of good magnetic property, low demagnetization rate, good mechanical property and poor chemical oxidation resistance, thereby limiting the application range of the Nd-Fe-B permanent magnetic powder to a certain extent. Many oxides can also derive from the magnetic powder in the production process, and the oxides are mixed with the magnetic powder, so that the magnetic performance of the magnet can be seriously influenced after the magnetic powder mixed with the oxides is manufactured into a magnet; in addition, the neodymium iron boron permanent magnet is easy to oxidize and rust in an actually used damp and hot environment, and the magnetic performance is reduced or damaged due to oxidation peeling failure, so that the service life of the neodymium iron boron permanent magnet is seriously influenced, and the stability and the reliability of the product are reduced. Therefore, the realization of the oxidation resistance and the corrosion resistance of the magnetic powder material is the premise of expanding the application range of the magnetic powder material.
Disclosure of Invention
1. Technical problem to be solved
Aiming at the problems in the prior art, the invention aims to provide a surface antioxidant treatment method of neodymium iron boron permanent magnet powder with low demagnetization rate, which comprises the steps of firstly spraying and cleaning the magnetic powder, and adopting a silane coupling agent to carry out molecular modification on the outer surface of the magnetic powder, so that the subsequent antioxidant treatment is easy to carry out on the outer surface of the magnetic powder, and the antioxidant treatment adopts a treating agent A spray coating and a treating agent B spray coating, so that the internal and external dual antioxidant protection of the surface of the magnetic powder is realized, the oxidation resistance of the magnetic powder is effectively improved, and meanwhile, in the process of the antioxidant treatment of the surface of the magnetic powder, the magnetic powder is placed in a high-temperature stirrer and is subjected to spray coating treatment, so that the film forming uniformity of the surface of the magnetic powder is effectively improved, and the film forming quality is effectively improved.
2. Technical scheme
In order to solve the above problems, the present invention adopts the following technical solutions.
A surface oxidation resistance treatment method of neodymium iron boron permanent magnet powder with low demagnetization rate comprises the following steps:
s1: magnetic powder surface pretreatment: mechanically sandblasting the magnetic powder to be treated to improve the surface friction force of the magnetic powder;
s2: cleaning magnetic powder: placing the magnetic powder treated in the S1 in distilled water for ultrasonic cleaning, removing stains on the surface of the magnetic powder, filtering, placing in a drying oven for vacuum drying, and keeping the drying temperature at 45-60 ℃;
s3: performing surface pre-oxidation resistance treatment on the magnetic powder: soaking the magnetic powder obtained in the step S2 in a silane coupling agent for 1-2h, taking out, filtering, and placing in a drying oven for vacuum drying again, wherein the drying temperature is kept at 45-60 ℃ for later use;
s4: and (2) performing surface antioxidation treatment on the magnetic powder, namely placing the magnetic powder obtained in the step S3 in a high-temperature stirrer, wherein the high-temperature stirrer is provided with a temperature display mechanism for observing and detecting the temperature in the high-temperature stirrer in real time, spraying a treating agent A on the magnetic powder in the high-temperature stirrer by using a spraying mechanism, uniformly coating the treating agent A on the magnetic powder to form an inner antioxidation film so as to finish primary antioxidation treatment, spraying a treating agent B on the magnetic powder after the primary antioxidation treatment by using the spraying mechanism, and uniformly coating the treating agent B on the magnetic powder to form an outer antioxidation film so as to obtain the low-demagnetization-rate neodymium iron boron permanent magnetic powder with double inoxidizability inside and outside.
Furthermore, the treating agent A is prepared from 40-60 parts of anhydrous phosphoric acid solution, 20-30 parts of pentaerythritol phenylpropionate solution, 5-8 parts of binder and 0.5-1 part of flatting agent in percentage by mass, the oxidation resistance of the treated magnetic powder is effectively improved through anhydrous phosphorylation treatment, the addition of the pentaerythritol phenylpropionate solution enables the film to have certain oxidation resistance after the film is formed, and the addition of the binder and the flatting agent effectively improves the adhesion force of the formed film.
Furthermore, the treating agent B is prepared from 50-65 parts of silane coupling agent, 20-30 parts of absolute ethyl alcohol solution and 2-6 parts of diluent in percentage by mass, the silane coupling agent is matched with the absolute ethyl alcohol solution, a layer of silane coupling film is additionally arranged on the formed film, and the double-layer film further effectively improves the oxidation resistance and the corrosion resistance of the magnetic powder.
Further, the silane coupling agent is KH550 silane coupling agent, the binder is polyurethane binder, the leveling agent includes but is not limited to one or more of isophorone and diacetone alcohol, and the diluent includes one or more of acetone, methyl ethyl ketone, n-butanol and styrene.
Further, the spraying mechanism is fixedly embedded at the top end of the high-temperature stirrer, the high-temperature stirrer is of a cylindrical tubular structure, the supports are mounted at the two ends of the high-temperature stirrer, the sealing door is rotatably mounted at one end of the high-temperature stirrer, the stirring mechanism is rotatably mounted inside the high-temperature stirrer, the driving mechanism for driving the stirring mechanism is mounted at the end, away from the sealing door, of the high-temperature stirrer, the electromagnetic valve is mounted at the bottom end of the high-temperature stirrer, the bottom end of the high-temperature stirrer is connected with the conical blanking port corresponding to the position of the electromagnetic valve, when the magnetic powder is subjected to surface oxidation resistance treatment, a technician introduces the magnetic powder to be treated into the high-temperature stirrer, sequentially sprays the treating agent A and the treating agent B onto the magnetic powder through the spraying mechanism to form a film on the surface of the magnetic powder, and stirs the magnetic powder through the stirring mechanism in the spraying process, the high temperature agitator provides high temperature drying.
Further, spout and cover mechanism and inlay including inlaying and establish the frame of establishing in the cavity on high temperature agitator top, the cavity inlays the bottom of establishing the frame and is linked together with the inside of high temperature agitator, the cavity inlays the internally mounted who establishes the frame and has the division board, the division board inlays cavity and establishes two fixed chambeies around the frame internal partitioning becomes, two fixed intracavity all installs the son and spouts and cover the mechanism, sets up two son and spouts and cover the mechanism and easily spout alone and cover the processing to processing agent A and processing agent B.
Further, the son spouts to cover the mechanism and establishes the board including inlaying and installing in inlaying of fixed intracavity, it establishes the board and has seted up a plurality ofly to inlay on its horizontal direction and establish the hole, and is a plurality of it establishes the spraying pipe that is connected with the nozzle all to inlay the hole, and is a plurality of it is connected through the connecting pipe to spout to cover the pipe, and the spraying pipe that is located the outer end has connect the feed liquor pipe outward, sets up a plurality of nozzles, easily spouts to cover evenly.
Further, rabbling mechanism installs the puddler in the high temperature agitator including rotating, fixedly connected with turns over the board on the lateral wall of puddler, it has seted up a plurality of sieve meshes to turn over the board one end that is close to the puddler, the outer end of puddler runs through the high temperature agitator and drives by actuating mechanism and be connected, the puddler is hollow columnar structure, a plurality of aeration holes have been seted up on the puddler is located the inside lateral wall of high temperature agitator, the outer end of puddler is external to have the high temperature intake pipe, and the high temperature intake pipe is connected with external high temperature air feeder for heat supply in to the high temperature agitator. Be provided with the bleeder vent on the lateral wall of high temperature agitator, stir when the heat supply, be favorable to improving the magnetic uniformity of being heated.
Further, actuating mechanism includes the rotating electrical machines of fixed mounting on the high temperature agitator, the drive end fixed mounting of rotating electrical machines has down drive gear, fixed mounting has the last drive gear who is connected with lower drive gear meshing on the lateral wall of puddler.
Further, the temperature display mechanism comprises a high-efficiency heat conducting plate fixedly arranged on the side wall of one end of the high-temperature stirrer, the inner end of the high-efficiency heat-conducting plate is embedded in the heat-preservation stirrer and is flush with the inner wall of the heat-preservation stirrer, the outer end of the high-efficiency heat-conducting plate is fixedly provided with an induction plate, a temperature display area is arranged outside the induction plates, the induction plates are provided with induction cavities communicated with the high-efficiency heat-conducting plate, the sensing cavity is filled with high-temperature sensing color-changing filler, the high-temperature sensing color-changing filler of the sensing cavity is doped with fluorescent powder, the high-temperature sensing color-changing filler can be temperature-sensing color-changing powder in the prior art, and other fluorescent powder is added into the temperature-sensing color-changing powder to be blended into color-changing color, namely, one color is changed into another color at a low temperature and at a high temperature, so that the temperature change can be sensitively sensed, and the temperature display area can be used for more specifically displaying the internal temperature of the high-temperature stirrer.
3. Advantageous effects
Compared with the prior art, the invention has the advantages that:
(1) this scheme is at first through spraying the magnetic, wash and adopt the silane coupling agent to carry out the molecular modification of magnetic surface, easily follow-up oxidation resistance treatment carries out at the magnetic surface, and oxidation resistance treatment adopts treating agent A to spout and covers and treating agent B spouts and cover, realize the inside and outside dual anti-oxidation protection on magnetic surface, effectively improve the oxidation resistance of magnetic, simultaneously in magnetic surface anti-oxidation treatment process, arrange the magnetic in the high temperature agitator and adopt and spout and cover the processing, the homogeneity of magnetic surface film forming has effectively been improved, thereby effectively improve the film quality.
(2) The treating agent A is prepared from an anhydrous phosphoric acid solution, a pentaerythritol phenylpropionate solution, a binder and a leveling agent in a ratio, the oxidation resistance of the treated magnetic powder is effectively improved through anhydrous phosphorylation treatment, the added pentaerythritol phenylpropionate solution enables the treated magnetic powder to have certain oxidation resistance after forming a film, the added binder and the leveling agent effectively improve the adhesion force of the formed film, the treating agent B is prepared from a silane coupling agent, an anhydrous ethanol solution and a diluent in a ratio, the silane coupling agent is matched with the anhydrous ethanol solution, a layer of silane coupling film is added on the formed film, and the double-layer adhesion film further effectively improves the oxidation resistance and the corrosion resistance of the magnetic powder.
(3) Spout and cover the fixed top of inlaying the high temperature agitator of locating of mechanism, spout and cover including two son in the mechanism and spout and cover the mechanism, be used for treating agent A and treating agent B spout alone and cover, the internally mounted of high temperature agitator rotates and installs rabbling mechanism, the one end that sealing door was kept away from to the high temperature agitator is installed and is carried out driven actuating mechanism to the rabbling mechanism, when carrying out surface oxidation resistance to magnetic, the technical staff will treat in the leading-in high temperature agitator of magnetic, successively spout on the magnetic and cover treating agent A and treating agent B through spouting to cover the mechanism, make the magnetic surface film-forming, and spout and cover the in-process and stir through rabbling mechanism, high temperature agitator provides high temperature drying.
(4) Rabbling mechanism installs the puddler in the high temperature agitator including rotating, fixedly connected with turns over the board on the lateral wall of puddler, it has seted up a plurality of sieve meshes to turn over the one end that the board is close to the puddler, the outer end of puddler runs through the high temperature agitator and drives by actuating mechanism and connect, the puddler is hollow columnar structure, a plurality of aeration holes have been seted up on the puddler is located the inside lateral wall of high temperature agitator, the outer end of puddler is external to have the high temperature intake pipe, the high temperature intake pipe is connected with external high temperature air feeder, be used for carrying out the heat supply in the high temperature agitator, be provided with the bleeder vent on the lateral wall of high temperature agitator, stir in the heat supply, be favorable to improving the magnetic degree of consistency of being heated.
(5) Temperature display mechanism includes the high-efficient heat-conducting plate of fixed mounting on high temperature agitator one end lateral wall, the outer end fixed mounting of high-efficient heat-conducting plate has the tablet, be provided with the temperature display district outside the tablet, the tablet all is equipped with the response chamber that is linked together with high-efficient heat-conducting plate, it has the high temperature response filler that discolours to respond to the intracavity packing, the high temperature response of response chamber is discolourd and is filled and is doped with phosphor powder in the filler, the temperature sensing of high temperature response filler can choose the temperature discoloration powder among the prior art for use, and it has the look to become coloured to add other phosphor powder blending in the temperature sensing discoloration powder, a low temperature colour high temperature becomes another colour, thereby can sensitively sense the change of temperature, and set up and show the inside temperature of high temperature agitator that the temperature display district can be more concrete.
Drawings
FIG. 1 is a flow chart of the present invention;
FIG. 2 is a perspective view of a high temperature agitator of the present invention
FIG. 3 is an internal perspective view of the hollow drop frame of the present invention;
fig. 4 is a schematic view of the internal structure of the high-temperature agitator of the present invention.
The reference numbers in the figures illustrate:
1 high-temperature stirrer, 2 sealing door, 3 support, 4 conical blanking port, 5 hollow embedded frame, 501 division plate, 502 embedded plate, 503 embedded hole, 6 spray coating pipe, 7 liquid inlet pipe, 8 stirring rod, 9 turning plate, 10 sieve holes, 11 rotating motor, 12 upper transmission gear, 13 lower transmission gear, 14 high-temperature air inlet pipe, 15 high-efficiency heat conducting plate, 16 induction plate and 17 temperature display area.
Detailed Description
The drawings in the embodiments of the invention will be combined; the technical scheme in the embodiment of the invention is clearly and completely described; obviously; the described embodiments are only some of the embodiments of the invention; but not all embodiments, are based on the embodiments of the invention; all other embodiments obtained by a person skilled in the art without making any inventive step; all fall within the scope of protection of the present invention.
In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "top/bottom", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "disposed," "sleeved/connected," "connected," and the like are to be construed broadly, e.g., "connected," which may be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.
Example 1:
referring to fig. 1, a surface antioxidant treatment method for low demagnetization rate neodymium iron boron permanent magnet powder includes the following steps:
s1: magnetic powder surface pretreatment: mechanically sandblasting the magnetic powder to be treated to improve the surface friction force of the magnetic powder;
s2: cleaning magnetic powder: placing the magnetic powder treated in the S1 in distilled water for ultrasonic cleaning, removing stains on the surface of the magnetic powder, filtering, placing in a drying oven for vacuum drying, and keeping the drying temperature at 45-60 ℃;
s3: performing surface pre-oxidation resistance treatment on the magnetic powder: soaking the magnetic powder obtained in the step S2 in a silane coupling agent for 1-2h, taking out, filtering, and placing in a drying oven for vacuum drying again, wherein the drying temperature is kept at 45-60 ℃ for later use;
s4: and (2) performing surface antioxidation treatment on the magnetic powder, namely placing the magnetic powder obtained in the step S3 in a high-temperature stirrer 1, wherein the high-temperature stirrer 1 is provided with a temperature display mechanism for observing and detecting the temperature in the high-temperature stirrer 1 in real time, spraying a treating agent A on the magnetic powder in the high-temperature stirrer 1 by adopting a spraying mechanism, uniformly coating the treating agent A on the magnetic powder to form an inner antioxidation film to finish primary antioxidation treatment, spraying a treating agent B on the magnetic powder after the primary antioxidation treatment by adopting the spraying mechanism, and uniformly coating the treating agent B on the magnetic powder to form an outer antioxidation film, so that the low-demagnetization-rate neodymium iron boron permanent magnetic powder with double inoxidizability inside and outside is obtained.
Specifically, the treating agent A is prepared from 40-60 parts by mass of an anhydrous phosphoric acid solution, 20-30 parts by mass of a pentaerythritol phenylpropionate solution, 5-8 parts by mass of a binder and 0.5-1 part by mass of a leveling agent, the oxidation resistance of the treated magnetic powder is effectively improved through anhydrous phosphorylation treatment, the addition of the pentaerythritol phenylpropionate solution enables the treated magnetic powder to have certain oxidation resistance after a film is formed, and the addition of the binder and the leveling agent effectively improves the adhesion force of the formed film.
The treating agent B is prepared by adopting a silane coupling agent with the mass fraction ratio of 50-65 parts, an absolute ethyl alcohol solution with the mass fraction ratio of 20-30 parts and a diluent with the mass fraction ratio of 2-6 parts, a layer of silane coupling film is additionally arranged on a formed film, the double-layer film arrangement further effectively improves the oxidation resistance and the corrosion resistance of the magnetic powder, specifically, the silane coupling agent is KH550 silane coupling agent, the binder is polyurethane binder, the leveling agent comprises one or more of isophorone and diacetone alcohol, and the diluent comprises one or more of acetone, methyl ethyl ketone n-butyl alcohol and styrene.
Referring to fig. 2-3, the spraying mechanism is fixedly embedded at the top end of the high-temperature stirrer 1, the high-temperature stirrer 1 is a cylindrical tubular structure, two ends of the high-temperature stirrer 1 are respectively provided with a bracket 3, one end of the high-temperature stirrer 1 is rotatably provided with a sealing door 2, the interior of the high-temperature stirrer 1 is rotatably provided with a stirring mechanism, one end of the high-temperature stirrer 1, which is far away from the sealing door 2, is provided with a driving mechanism for driving the stirring mechanism, the bottom end of the high-temperature stirrer 1 is provided with an electromagnetic valve, the bottom end of the high-temperature stirrer 1 is connected with a conical blanking port 4 corresponding to the electromagnetic valve, when the magnetic powder is subjected to surface oxidation resistance treatment, a technician introduces the magnetic powder to be treated into the high-temperature stirrer 1, and sequentially sprays a treating agent a and a treating agent B onto the magnetic powder through the spraying mechanism to form a film on the surface of the magnetic powder, and stirs through the stirring mechanism during the spraying process, the high-temperature stirrer 1 provides high-temperature drying, after the treatment is completed, the electromagnetic valve is opened, and the magnetic powder is collected through the conical blanking port 4.
Specifically, the spraying mechanism comprises a hollow embedding frame 5 which is embedded in the top end of the high-temperature stirrer 1, the bottom end of the hollow embedding frame 5 is communicated with the inside of the high-temperature stirrer 1, a partition plate 501 is arranged in the hollow embedding frame 5, the partition plate 501 divides the hollow embedding frame 5 into a front fixed cavity and a rear fixed cavity, sub-spraying mechanisms are arranged in the two fixed cavities, the two sub-spraying mechanisms are easy to spray a treating agent A and a treating agent B independently, the sub-spraying mechanisms comprise embedding plates 502 which are arranged in the fixed cavities, a plurality of embedding holes 503 are formed in the embedding plates 502 in the horizontal direction, spraying pipes 6 connected with nozzles are embedded in the embedding holes 503, the spraying pipes 6 at the outer ends are connected through connecting pipes, a liquid inlet pipe 7 is arranged outside the spraying pipes 6 at the outer ends, and the liquid inlet pipe 7 is connected with external spraying equipment to realize the connection of the internal spraying pipe, the internal spraying pipe and the external spraying pipe 7, And the treating agent B is sprayed to realize the full mixing of the treating agent and the magnetic powder.
Referring to fig. 4, the stirring mechanism includes a stirring rod 8 rotatably installed in the high temperature stirrer 1, a turning plate 9 is fixedly connected to a side wall of the stirring rod 8, a plurality of sieve holes 10 are formed at one end of the turning plate 9 close to the stirring rod 8, an outer end of the stirring rod 8 penetrates through the high temperature stirrer 1 and is driven by a driving mechanism to be connected, the stirring rod 8 is of a hollow columnar structure, a plurality of aeration holes are formed in a side wall of the stirring rod 8 located inside the high temperature stirrer 1, a high temperature air inlet pipe 14 is externally connected to an outer end of the stirring rod 8, the high temperature air inlet pipe 14 is connected to an externally connected high temperature steam device, so that high temperature steam is introduced into the high temperature stirrer 1, the stirring rod 8 stirs the magnetic powder under the action of the driving mechanism, which is beneficial to improving the rapid and uniform drying treatment of the magnetic powder after being sprayed with the treatment agent, and the high temperature steam is introduced into the high temperature stirrer 1 through the plurality of aeration holes, the high-temperature diffusion is facilitated, the driving mechanism comprises a rotating motor 11 fixedly mounted on the high-temperature stirrer 1, a lower transmission gear 13 is fixedly mounted at the driving end of the rotating motor 11, an upper transmission gear 12 meshed with the lower transmission gear 13 is fixedly mounted on the side wall of the stirring rod 8, synchronous transmission of the meshing gears is the prior art, the rotating motor 11 is used for driving the stirring rod 8 to rotate, and a person skilled in the art can select a motor with a proper model for mounting.
In addition, please refer to fig. 2, the temperature display mechanism includes a high-efficiency heat conducting plate 15 fixedly installed on a side wall of one end of the high-temperature stirrer 1, an inner end of the high-efficiency heat conducting plate 15 is embedded in the heat preservation stirrer 1 and is flush with an inner wall thereof, an outer end of the high-efficiency heat conducting plate 15 is fixedly installed with an induction plate 16, a temperature display area 17 is arranged outside the induction plate 16, the induction plates 16 are respectively provided with an induction cavity communicated with the high-efficiency heat conducting plate 15, the induction cavity is filled with a high-temperature induction color-changing filler, the high-temperature induction color-changing filler of the induction cavity is doped with fluorescent powder, the high-temperature induction color-changing filler can be selected from temperature-changing powder in the prior art, and other fluorescent powder is added into the temperature-changing powder to be adjusted into color-changing color, i.e. one color at low temperature and high temperature changes can be sensitively sensed, thereby playing a role of striking temperature changes, and the temperature display area 17 can display the internal temperature of the high-temperature stirrer specifically.
The above; but are merely preferred embodiments of the invention; the scope of the invention is not limited thereto; any person skilled in the art is within the technical scope of the present disclosure; the technical scheme and the improved concept of the invention are equally replaced or changed; are intended to be covered by the scope of the present invention.