WO1999023675A1 - HIGH CORROSION-RESISTANT R-Fe-B-BASE BONDED MAGNET AND METHOD OF MANUFACTURING THE SAME - Google Patents

Abstract

A method of efficiently manufacturing R-Fe-B-base bonded magnets of various shapes such as ring shape and disk shape having a high corrosion resistance and capable of being plated electrically with ease, wherein the corrosion resistance of the magnet is improved by forming a conductive film of a metal on the surface thereof with tight adhesion, uniformity and efficiency. The method comprises filling the holes of the magnet with polishing powder, inorganic powder and polishing chips, fixing these materials in the holes by fat of a vegetable medium and sealing the resultant holes, and barrel-polishing the magnet by a barrel unit in the dry process with indefinitely shaped, i.e. spherical, massive or acicular (wiry) pieces of a required size of Cu, Sn, Zn, Pb, Cd, In, Au, Ag, Fe, Ni, Co, Cr and Al and such pieces of alloys thereof used as a metallic medium. Said fine pieces of metals such as Cu are press fitted into a resin surface and holes of the bonded magnet and cover the surface and holes and further, cover the surfaces of particles of magnetic powder whereby a very uniform conductive film can be formed on the surface of the bonded magnet, so that it becomes possible to subject the bonded magnet to electric plating excellently and obtain a plated R-Fe-B-base bonded magnet of a high corrosion resistance and with minimum deterioration of the magnetic properties.

Description

 Specification

 High corrosion resistance R-Fe-B bonded magnet and its manufacturing method

 The present invention relates to an R-Fe-B bonded magnet having various shapes, such as a ring shape and a disk shape, having improved corrosion resistance with a metal film having high cleanliness. Polishing dust and inorganic powder are buried in the pores to seal and smooth the surface, or without the above-mentioned sealing treatment, Cu, Sn, Zn, Pb, Cd, In, Au , Ag, Fe, Ni, Co, Cr, Al and its alloy pieces are crushed by dry barrel polishing using a metal media, and the crushed metal flakes are bonded to the resin surface of the bonded magnet surface and the voids or sealing portions. By press-fitting and coating the surface of the magnet, and by coating the surface of the magnetic powder with fine metal particles, sufficient conductivity is imparted to the magnet surface, enabling direct electroplating without electroless plating. Further, after the formation of the A1 coating layer, a zinc substitution treatment is performed. High corrosion resistance R-Fe-B with a high corrosion resistance coating layer that can be formed efficiently and with high productivity without limiting the plating bath such as electrolytic Ni plating The present invention relates to a bonded magnet and its manufacturing method. Background art

Today, bonded magnets called rubber magnets or plastic magnets made of various shapes such as rings and discs have been replaced by conventional isotropic bonded magnets to anisotropic bonded magnets and ferrite-based bonded magnets. R-Fe-B-based magnets that use R-Fe-B-based magnetic materials that exhibit high magnetic properties with a maximum energy product of 50MGOe or more for sintered magnets High performance has been achieved for bonded magnets. R-Fe-B bonded magnets have a problem that they are prone to cracking due to the fact that they contain a large amount of Fe and a highly oxidizable component phase in the magnet alloy composition, and a resin layer of various compositions is electrodeposited on the surface. , A spray method, an immersion method, an impregnation method and the like (for example, JP-A-1-66519, JP-A-1-245504).

 In the case of the resin coating method used to improve the corrosion resistance of R-Fe-B bonded magnets, such as the spray method, ring-shaped bonded magnets have a large loss of paint, and the back and front are reversed. Therefore, there are problems that the number of steps is large and the uniformity of the film thickness is poor.

 In addition, in the electrodeposition coating method, the film thickness is uniform, but it is necessary to attach each of the magnets to an electrode, and repair of the electrode part removed after painting, that is, touch-up is required. However, there is a problem that it requires a lot of man-hours and is particularly unsuitable for small items.

 With the immersion method, it is difficult to obtain a coating film with a uniform and uniform film thickness due to problems such as sagging of paint.In addition, pores are not sufficiently filled with porous bonded magnets, and swelling occurs when drying. There are problems such as adhesion between products.

 Regarding the method of forming the metal coating, in consideration of mass productivity, the electric metal plating performed by the sintered R-Fe-B magnet should be applied (Japanese Patent Application Laid-Open Nos. 60-54406 and 62-120003). However, since the R-Fe-B bonded magnet surface is porous and the resin part with low conductivity is exposed, the plating solution remains or the plating film is sufficiently formed on the resin part. Pinholes (non-plated parts) are generated, and firing occurs.

 Therefore, a method of selecting a plating solution that is harmless even if it penetrates and remains on a porous bonded magnet (Japanese Patent Laid-Open No. 4-276092) or a method of plating after applying a resin coating to the base (Japanese Patent Laid-Open No. 3-11714) And Japanese Patent Laid-Open No. 4-276095) have been proposed.

However, it is difficult to adjust the pH of the plating solution or completely render it harmless, and no plating bath with good film formation efficiency has been found. There is a contradiction that if a stable element is applied and a sufficiently thick undercoating is applied, the surface plating layer is not required.

 A plating bath with a specific composition has been proposed as a method of applying Ni plating with high film formation efficiency to R-Fe-B-based bonded magnets (Japanese Patent Application Laid-Open No. 4-99192). There is a danger of intrusion and residual fire.

 On the other hand, for structural materials, Cu strike plating, which is usually performed before Ni plating, is either strongly alkaline or strongly acidic, and is unsuitable for processing R-Fe-B based bonded magnets. is there.

 In addition, high-temperature acid bath type NiP plating has been put into practical use to impart abrasion resistance to electronic components or as a heat treatment for automotive steel sheets. It is not suitable for application because it corrodes the inside of the magnet. Therefore, it is possible to prevent the plating liquid and cleaning liquid from penetrating and remaining in the porous R-Fe-B bonded magnet, and to efficiently form a plating layer such as electric Ni plating, thereby improving corrosion resistance. As a method for manufacturing an R-Fe-B bonded magnet consisting of

 (1) A method of coating a mixture of resin and conductive powder on the surface of an R-Fe-B bonded magnet and forming a conductive coating layer on the surface of the material.

 (2) A method in which an adhesive resin layer is formed on the surface of an R-Fe-B bonded magnet, and a metal powder is adhered to form a conductive coating layer on the material surface (JP-A-5-302176) .

 (3) A method in which a mixture of resin and conductive powder is applied to the surface of an R-Fe-B-based bonded magnet to form a conductive coating layer, and then subjected to a surface smoothing treatment (Japanese Patent Application Laid-Open No. 9-186016). Has been proposed.

 However, the above three methods are preferable because various resins are used to seal the pores of the material, and the process of applying (impregnating) and curing (smoothing) the resin is complicated. Not good.

In addition, it is difficult to apply the resin uniformly to the surface of the material by the method of applying (impregnating) the resin of the material. It is difficult to get a stall. Further, the conductive coating layer is a resin layer containing a conductive substance or metal powder, and the resin exposed portion of the bonded magnet on the surface is improved as compared with the R-Fe-B based bonded magnet material. However, it is difficult to obtain a uniform and good conductive surface because there are not a few exposed portions of the coating resin due to the manufacturing method, and there are low conductivity parts on the surface. There are problems such as the tendency to occur.

 Therefore, the inventor of the present invention carried out barrel polishing by a dry method using a mixture of a vegetable medium or a surface-modified vegetable medium and an abrasive with the abrasive, as a medium. A method of forming a conductive layer by electroless copper plating in an alkaline bath by fixing and sealing the pores in the pores of a bonded magnet with vegetable oils and fats and sealing the surface.

 However, there is a problem that the electroless copper plating has a short plating solution life and it is difficult to control the solution to obtain a good plating film. Furthermore, although corrosion resistance and dimensional accuracy are better than before, even higher corrosion resistance is required to meet today's various applications. Disclosure of the invention

 An object of the present invention is to provide an R-Fe-B bonded magnet having extremely high corrosion resistance, which does not occur even in a long-time high-temperature high-humidity test, and has an extremely high adhesion strength in order to realize high corrosion resistance. An object of the present invention is to provide a manufacturing method capable of uniformly forming various corrosion resistant coatings on an R-Fe-B-based bonded magnet.

In addition, the present invention provides high adhesion strength and high dimensional accuracy on the magnet surface, which prevents the plating solution and cleaning solution from entering and remaining in the porous R-Fe-B bond magnet in the conventional electroless plating method. The purpose of the present invention is to provide a method for manufacturing a high corrosion-resistant R-Fe-B-based bonded magnet comprising an industrial process most suitable for providing a corrosion-resistant coating. With regard to the electroplating technology of R-Fe-B bonded magnets with excellent corrosion resistance and surface cleanliness, the inventors have focused on the fact that it is important to impart conductivity to the surface of the material extremely uniformly. As a result of various investigations on the method of forming the conductive film, the R-Fe-B bonded magnet was converted to a barrel device using irregular shaped Cu pieces of the required dimensions, such as spherical, massive or needle-like (wire), as metal media. By applying barrel polishing by a dry method, the crushed Cu fine particles are pressed into the resin surface and pores of the bonded magnet surface and coated, and the magnetic particle surface is also coated with Cu fine particles. R-Fe-B bonded magnet R-Fe-B bonded magnet with extremely uniform conductive film on magnet surface and good electrical plating, excellent corrosion resistance, and less deterioration of magnetic properties It was found that a coated product could be obtained.

Further the inventors found that when the smoothness of the bonded magnet surface is obtained, a result of various studies to solve the problems described above, porous the R-Fe-B bonded magnet, such as A1 ₂ 0 _3, SiC A mixture of an abrasive obtained by baking inorganic powder and a vegetable medium such as fruit husk or corn core, or a mixture of the above abrasive and a vegetable medium whose surface has been modified with the inorganic powder And then subjecting it to barrel polishing by a dry process to remove abrasive debris such as abrasive powder, inorganic powder for reforming, and the surface oxide layer of the magnetic powder constituting the bonded magnet, using the oils and fats of the vegetable medium Since it is possible to fix and seal the pores of the magnet and to smooth the surface at the same time, it is possible to form a conductive film directly on the surface of the magnet material after dry barrel polishing. Improved smoothness and resistance It was found that sex can further excellent Rukoto obtain an R-Fe-B based bonded magnet.

In addition, in addition to the above-mentioned Cu pieces, the inventors of the present invention have reported that soft metal pieces of Sn, Zn, Pb, Cd, In, Au, and Ag having a Vickers hardness value of 80 or less, , Co, and Cr can be used as media. In addition, the inventors used an amorphous A1 piece as a medium, and performed barrel polishing by a dry method using a barrel device, so that the ground A1 pieces were bonded to the surface of the bonded magnet. The surface of the A1 coating layer formed on the surface of the R-Fe-B bonded magnet is zinc-substituted by press-fitting and coating the resin surface and sealing portion of As a result, it is possible to prevent the outflow of A1 at the time of electroplating, to achieve good electroplating, to obtain an R-Fe-B-based bonded magnet plated coating having excellent corrosion resistance and little deterioration in magnetic properties. We have found that we can do this and completed this invention. BEST MODE FOR CARRYING OUT THE INVENTION

 The high corrosion resistance R-Fe-B-based bonded magnet according to the present invention is:

R-Fe-B bonded magnet

Jihi, 811, 211,? 15, J 111 116,: 1 ^ 0, ^ 1 and its alloys are press-fitted and coated with metal particles, and the surface of magnetic powder is coated with metal particles to form metal on the surface of the magnet. It is characterized by having a coating layer and an electrolytic plating layer formed via the metal coating layer.

 In the high corrosion-resistant R-Fe-B-based bonded magnet according to the present invention, the pores forming the surface of the R-Fe-B-based bonded magnet include abrasive powder, polishing debris of the bonded magnet, and inorganic material. After the porous powder is fixed and sealed with the oils and fats of the vegetable medium, the metal particles are pressed into and coated on the resin surface constituting the surface and the sealing portion, and on the magnetic powder surface constituting the surface. The magnet is characterized by having the metal coating layer on the surface of the magnet formed by coating metal particles and an electrolytic plating layer formed via the metal coating layer. The R-Fe-B bonded magnet having high corrosion resistance according to the present invention is characterized in that A1 fine particles are press-fitted and coated on the resin surface constituting the surface and the sealing portion, and A1 fine particles are adhered on the magnetic powder surface constituting the surface. Has an A1 coating layer formed by coating, a zinc layer by zinc substitution treatment on the surface of the magnet, and an electrolytic plating layer formed through the coating layer. .

In the present invention, R-Fe-B bonded magnets are intended for both isotropic and anisotropic bonded magnets. For example, in the case of compression molding, thermosetting of magnetic powder having the required composition and properties It is obtained by adding and kneading a curable resin, a coupling agent, lubrication, etc., then compressing and heating to cure the resin. In the case of injection molding, extrusion molding, and rolling molding, a thermoplastic resin is added to the magnetic powder. It is obtained by adding and kneading a coupling agent, lubrication, etc., and then molding by any of injection molding, extrusion molding, and rolling molding.

 The R-Fe-B-based magnetic material powder is prepared by dissolving the required R-Fe-B-based alloy and pulverizing it after production. Melting R-Fe-B alloy using a jet caster to obtain ribbon foil and pulverizing and annealing it, quenching alloy, dissolving required R-Fe-B alloy, pulverizing it by gas atomization and heat-treating Gas atomization method, powdering the required raw material metal, pulverizing it by mechanical alloying and heat-treating it.Mechanical alloying method and heating and decomposing and recrystallizing the required R-Fe-B alloy in hydrogen Isotropic and anisotropic powders obtained by various production methods such as a method for making the particles (HDDR method) can be used.

 In the present invention, the rare earth element R used in the R-Fe-B-based magnet powder occupies 10 to 30 atomic% of the composition, but at least one of Nd, Pr, Dy, Ho, and Tb, or , 1 ^, 06, 8111, & (1 1 ^ 11,1¾1, ¥ 1) and 1 ^ 1, ¥ are preferable. In general, one kind of R is sufficient, but in practice, a mixture of two or more kinds (mish metal, sijim, etc.) can be used for convenience and other reasons. Note that R may not be a pure rare earth element, and may contain impurities that are unavoidable in production as far as it is industrially available.

 R is an essential element in the above-mentioned system magnet powder, and if it is less than 10 atomic%, the crystal structure becomes a cubic structure having the same structure as a-iron, so that high magnetic properties, particularly high coercive force, cannot be obtained. If it exceeds 30 atomic%, there will be many R-rich non-magnetic phases, and the residual magnetic flux density (Br) will decrease, so that a permanent magnet with excellent characteristics cannot be obtained. Therefore, R is preferably in the range of 10 atomic% to 30 atomic%.

B is an essential element in the above-mentioned system magnet powder. If it is less than 2 atomic%, the rhombohedral structure becomes the main phase, a high coercive force (iHc) cannot be obtained, and if it exceeds 28 atomic%, it becomes B-rich. Since there are many non-magnetic phases and the residual magnetic flux density (Br) decreases, an excellent permanent magnet cannot be obtained. Therefore, B is desirably in the range of 2 to 28 atomic%.

 Fe is an essential element in the above-mentioned system magnet powder, and if it is less than 65 atomic%, the residual magnetic flux density (Br) decreases, and if it exceeds 80 atoms, a high coercive force cannot be obtained. Atomic% is desirable.

 Also, substituting part of Fe with Co can improve the temperature characteristics without impairing the magnetic properties of the obtained magnet, but conversely when the Co substitution amount exceeds 20% of Fe, It is not preferable because the magnetic properties deteriorate. When the substitution amount of Co is 5 atomic% in the total amount of Fe and Co> ~ 15 atomic%, (Br) increases as compared with the case where no substitution is made, and thus it is preferable to obtain a high magnetic flux density.

 Also, in addition to R, B, Fe, the presence of unavoidable impurities in industrial production can be tolerated.For example, a part of B is 4.0 wt% or less C, 2.0 wt% or less P, 2.0 wt% or less. By replacing at least one of S and Cu of 2.0 wt% or less with a total amount of 2.0 wt% or less, it is possible to improve the productivity of permanent magnets and reduce the cost.

 In addition, at least one of Al, Ti, V, Cr, Mn, Bi, Nb, Ta, Mo, W, Sb, Ge, Ga, Sn, Zr, Ni, Si, Zn, and Hf is included in the magnet powder. On the other hand, it can be added because it has the effect of improving the coercive force and the squareness of the demagnetization curve or improving the manufacturability and reducing the price. The upper limit of the addition amount is desirably in a range that satisfies the conditions necessary for setting the (BH) max and (Br) values of the bonded magnet to required values.

Also, in the present invention, 6 Pa, 12 Pa, PPS, PBT, EVA, etc. are used as a resin for the injection molding for the binder, and PVC, NBR, CPE, NR, Hibaron, etc. are used for the extrusion molding, the calender roll, the rolling molding, and the compression molding is used. As the resin, epoxy resin, DAP, phenol resin, etc. can be used, and a known metal binder can be used if necessary. Further, as the auxiliary material, a lubricant for facilitating molding, a binder between a resin and an inorganic filler, a silane-based or titanium-based coupling agent, or the like can be used. In the present invention, sealing, in the media at the time of barrel polishing for smoothing treatment, a polishing material such as A1 ₂ 0 _3, inorganic powders baked compacted ceramics such as SiC or a metal ball, plant sexual Kawakuzu, sawdust, fruit shells, such as the core of the corn mixture of vegetable medium, or the abrasive and the A1 ₂ 0 _3, SiC at inorganic powder such as surface modified above A mixture of vegetable media is used. By performing barrel polishing using this mixture as a medium, it becomes possible to perform smooth sealing of the bonded magnet.

 A well-known barrel can be used for the sealing and smoothing treatment and the dry barrel polishing for forming the metal coating layer on the surface of the bonded magnet according to the present invention, and a rotating barrel having a general rotation speed of 20 to 50 rpm and a rotation speed of 70 can be used. A centrifugal barrel of ~ 200 rpm, a vibration barrel polishing method with a vibration amplitude of 0.5 nmi or more and less than 50 mm can be adopted.

The atmosphere of the barrel polishing is usually may be in the air, but by the media has frictional heat in barrels polishing, if an acid I spoon magnet is concerned, N _2, Ar, alone such as He Alternatively, the atmosphere may be an inert gas atmosphere such as a mixed gas thereof. In the present invention, in the case of a rotating barrel and a vibrating barrel to be used for sealing and smoothing processing, when the total amount of the bonded magnet, the abrasive and the vegetable medium to be charged into the barrel is less than 20%, the processing amount is reduced. If it is too small, it is not practical. If it exceeds 90%, stirring is insufficient and sufficient polishing cannot be performed. Therefore, 20% to 90% of the internal volume is preferable.

Sealing of the present invention, the abrasive in the smoothing process is not particularly limited, the particle diameter l ~ 7 mm, preferably 3 ~ 5 mm approximately abrasive and diameter 0.5 ~ 3 mm, preferably a plant of the order of diameter l ~ 2m _m Using a medium or a mixture of the above-mentioned vegetable medium whose surface has been modified with the above-mentioned abrasive and inorganic powder, the mixture of the magnet and the medium is uniformly stirred, and under the condition that the relative movement is performed. It is preferred to do so.

As the modified vegetable medium surface at the inorganic powder, after the grease, such as wax vegetable medium surface kneaded coatings, particle size _{0.01 ~ 3μπι A1 2 0 3,} SiC, ZrO, MgO inorganic powder uniformly spread on the surface and fixed You. The powder of the abrasive, the inorganic powder for modifying the surface of the vegetable medium, and the swarf of the bonded magnet, which are sealing materials, have a particle size of 0.01 to 3 μπι.

 The ratio of the vegetable medium to the abrasive in the media (vegetable medium / abrasive) is 1/5 to 2, and a mixture having a ratio of 1 is preferred. Also, the mixing ratio (bond magnet / media) of the bond magnet and the medium is preferably 3 or less.

 In the present invention, the abrasive material effectively grinds and removes a surface oxide layer of the magnet, smoothes the surface, and powders of the abrasive material and an inorganic powder for modifying the surface of a vegetable medium, and a bonded magnet. The above-mentioned vegetable medium has an effect of improving the adhesive force of the sealed object by effectively releasing the oil and fat thereof, by tapping and solidifying the sealed object such as abrasive dust.

 In the present invention, the porosity of the bonded magnet after the surface smoothing treatment can be reduced to 3% or less. Not only the smooth sealing treatment of the bonded magnet surface but also the oxide surface of the magnet is removed to activate the magnet. The surface of the R-Fe-B based magnetic powder can be obtained.

 In the present invention, a known barrel device such as a rotary type, a vibration type, and a centrifugal type can be used for dry barrel polishing with a metal piece. The shape of the metal piece can be irregular, such as spherical, massive, or needle-like (one wire) .If the size of the metal piece is less than 0.1 mm, it takes a long time to press-fit and coat it practically. However, if it exceeds 10 mm, the surface unevenness becomes large, and the metal cannot be coated on the entire surface.Therefore, the size of the metal piece is preferably 0.1 mm to 10 mm, more preferably 0.3 mm to 5 mm. A more preferred range is 0.5 mm to 3 mm.

Further, in the present invention, the metal pieces to be charged into the dry barrel may have the same shape and dimensions, or may mix different shapes and dimensions. Also, fine metal powder may be mixed into the irregular shaped metal piece. Further, the composite metal may be the metal alone or an alloy, or a Cu composite metal in which a different metal such as Fe, Ni, or Al as a core material is coated with Cu. Also, it is desirable that the ratio to be charged for dry barrel polishing and the volume ratio between magnet and metal piece (magnet / metal) is 3 or less. If it exceeds 3, it takes time for press-fitting and coating of metal, which is not practical, and This is because the magnetic particles are shed from the magnet surface.

 The amount of bonded magnets and metal pieces to be charged into the barrel polishing machine is

If it is less than 20%, the treatment amount is too small to be practical, and if it exceeds 90%, there is a problem that stirring is insufficient and sufficient polishing cannot be performed.

 The metal flakes to be pressed and coated are fine powder or needle-shaped pieces.If the diameter exceeds 5μπι, the adhesion to the magnet surface is not good, and poor adhesion and peeling during electrolytic plating Therefore, the major diameter was set to 5 μπι or less. A preferred range is 2 μπι or less in major axis.

 In the present invention, with regard to press-fitting and coating of metal particles, the metal particles are press-fitted and coated on a resin surface and a hole portion and a magnetic powder surface of a bonded magnet surface, and on a soft resin surface and a hole portion on a bonded magnet surface. The surface of the magnetic powder is coated. The amount press-fitted into the resin surface and the pores increases toward the surface, and the content gradually decreases inside the resin layer.

 In the present invention, the thickness of the metal press-fit layer on the resin surface and the pores is preferably Ο.ΐμιη or more and 2 μπι or less.If the thickness is less than Ο.ΐμπι, sufficient conductivity cannot be obtained. No, but time consuming and impractical.

 The thickness of the metal coating layer on the magnetic powder surface of the bonded magnet surface is preferably 0.2 μπι or less, and the reaction between the magnetic powder surface and the metal particles is a kind of mechanochemical reaction.

If it exceeds 0.2 μπι, the adhesion is inferior.

 In the case of the dry method barrel polishing according to the present invention, the number of rotations is 20 to 50 rpm for a rotary barrel, 70 to 200 rpm for a centrifugal barrel, and 50 to 50 rpm for a vibration barrel polishing method. : L00 Hz, vibration amplitude 0.3 to 10 mm is preferred.

In the present invention, when the metal fine particles are press-fitted and coated on the surface of the magnet by the barrel polishing method, the atmosphere of the barrel polishing method may be in the air, but the irregular shaped metal pieces used as a medium and the ground metal fine pieces and the magnet are used. Friction heat during barrel polishing due to magnetic powder on the surface In the barrel polishing method, the atmosphere may be a single gas such as N ₂ , Ar, He, or a mixture of gases, etc. Preferred is in an inert gas.

 In the present invention, the reason why zinc is substituted on the A1 coated surface is to prevent the outflow of A1 at the time of subsequent electric plating. The zinc substitution method is preferably carried out using a solution containing zinc oxide, sodium hydroxide, ferric chloride, rosserile salt, and the like. Processing conditions are preferably immersion with a bath temperature of 10 ° C. to 25 ° C. and a processing time of 10 seconds to 120 seconds.

 As the zinc replacement method, a treatment of washing → zinc replacement → washing is preferable. If there is dirt or other deposits on the A1 surface, it is better to immerse and degrease it in a solution of sodium carbonate and sodium triphosphate for cleaning. The formed Zn layer is

It is formed in the form of ΖηΟ (Χ = 0 to 1), and the thickness of the formed Zn layer is preferably Ο.ΐμηι or less. If the layer thickness exceeds Ο.ΐμηι, poor adhesion occurs, which is not preferable.

 In the present invention, at least one metal selected from Ni, Cu, Sn, Co, Zn, Cr, Ag, Au, Pb, Pt, etc. or an alloy thereof is B, S, P Is preferred, and particularly preferred is Ni plating. The plating thickness is 50 μπι or less, preferably 10 to 30 μπι. In the present invention, press-fitting and coating of the metal fine powder into the resin surface and the pores described above have an effective action, so that plating can be performed even with a general pet bath, and fineness, excellent adhesion, and corrosion resistance can be obtained.

In particular, the plating method for the Ni plating bath is preferably performed in the steps of washing → electrical Ni plating—washing _→ drying.

Treatment at pH 4.0 to 4.6 and 50 ° C to 60 ° C is preferred.

 Ni plating uses the above-mentioned plating bath, the anode is an electrolytic nickel plate, the required current is applied, and the electric Ni plating is used to stabilize the elution of Ni from the anode Ni plate. It is desirable to use an Estland nickel chip containing

The plating method of the Ni plating bath is preferably performed in the steps of washing, electroplating, washing, and drying, and drying is preferably performed at 70 ° C. or more. Various bathtubs can be used for the plating bath according to the shape of the bond magnet. In the case of a ring-shaped bond magnet, trapping plating and barrel plating are preferable. Example

 Example 1

Ndl2at% prepared by the rapid solidification method, Fe77at%, B6at%, and kneaded to an epoxy resin 2 wt% to the alloy powder having an average particle size 150μπι having the composition Co5at%, after compression molding at a pressure of 7 ton / cm ² Cure at 170 ° C for 1 hour, outer diameter 22mmX inner diameter

A ring-shaped bonded magnet of 20 mm × 3 mm height was produced. The properties of the obtained bonded magnet were Br6.7 kG, iHc8.9 kOe, and (BH) max 9.0 MGOe.

 The resulting bonded magnet was placed in a vibration barrel, and dry barrel polishing was performed using a short cylindrical Cu piece having a diameter of lmm and a length of lmm to form a conductive coating layer of Cu fine particles. The depth of press-fit coating on the resin surface of the Cu particles is about 0.7μπι, and the coating thickness on the magnetic powder surface is Ο.ΐμιη.

 The processing conditions for barrel polishing were as follows: in an atmosphere iiAr gas, in a vibrating barrel with a vibration frequency of 70 Hz and a vibration amplitude of 3 mm, 50 bonded magnets (apparent volume 0.15 weight 100 g) and Cu pieces of the above dimensions (apparent volume) 2Z, weight 10kg), and the total charge was 60% of the barrel inner volume, and the treatment was performed for 3 hours.

Thereafter, cleaning was performed, and electric Ni plating was performed by a hook plating method. The film thickness after plating was 20 μπι on the inner diameter side and 22 μπι on the outer diameter side. The obtained ring-shaped bonded magnet was subjected to an environmental test (moisture resistance test) at 80 ° C and a relative humidity of 90% for 500 hours. Table 1 shows the properties of the magnet before and after the moisture resistance test, and Table 2 shows the surface condition results and the film thickness dimensional accuracy during the moisture resistance test. The conditions for electric Ni plating were as follows: current density 2 A / dm ² , plating time 60 minutes, pH 4.2, bath temperature 55 ° C, plating solution composition: 240 g / Z nickel sulfate, 45 g nickel chloride / appropriate nickel carbonate (pH adjustment), and the amount of boric acid was 30 g / rC.

 Comparative Example 1

 After washing the ring-shaped bonded magnet obtained in the same manner as in Example 1, electroless copper plating was performed. The plating thickness was 5 μπι. After the electroless copper plating, Ni plating was performed under the same conditions as in Example 1. The resulting ring-shaped bonded magnet was subjected to an environmental test (moisture resistance test) at 80 ° C and a relative humidity of 90% for 500 hours. Tables 1 to 3 show the results.

 The conditions for the electroless copper plating were a plating time of 20 minutes, a pH of 11.5, and a bath temperature of 20 ° C. The composition of the plating solution was 29 g of copper sulfate, 25 g of sodium carbonate / 140 g of tartrate, 40 g of sodium hydroxide, 37% formaldehyde was 150 mrC.

 Comparative Example 2

 After washing the ring-shaped bonded magnet obtained in the same manner as in Example 1, a phenol resin and Ni powder were mixed to form a conductive film having a thickness of μππι. After the treatment, Ni plating was performed under the same conditions as in Example 1. The resulting ring-shaped bonded magnet was subjected to an environmental test (moisture resistance test) at 80 ° C and a relative humidity of 90% for 500 hours. Tables 1 to 3 show the results.

 The conductive film treatment conditions were as follows: treatment time: 30 minutes; treatment liquid composition: 5 wt% of phenol resin, 5 wt% of Ni powder (particle size: 0.7 μπι or less), and 90 wt% of MEK (methyl ethyl ketone).

 Comparative Example 3

After washing the ring-shaped bonded magnet obtained in the same manner as in Example 1, forming a phenol resin layer as an adhesive layer in advance by a dipping method, and then attaching Ag powder (particle diameter 0.7 μπι or less) to the surface Then, a conductive coating layer having a thickness of 7 μπι was formed using a vibration barrel. After the vibration barrel treatment, Ni plating was performed under the same conditions as in Example 1. The resulting ring-shaped bonded magnet was subjected to an environmental test (moisture resistance test) at 80 ° C and a relative humidity of 90% for 500 hours. The results are shown in Tables 1 to 3. The vibration barrel processing conditions were as follows: a vibration barrel with a capacity of 3.5 was used, 50 bonded magnets were inserted, and a 2.5 mm steel ball with an apparent volume of 2 was used as a medium for 3 hours.

 As is clear from Tables 1 and 2, Comparative Example 1 showed spotting after about 100 hours, Comparative Example 2 300 hours later, and Comparative Example 3 also showed about 350 hours later. On the other hand, in Example 1, there were no spots observed under a microscope of 30 times even after 500 hours.

(Magnetic properties after material rise)-(Magnetic properties after moisture resistance test) Magnetic property degradation rate (%) = — -—————- X 100

(Magnetic characteristics of material rise) Film thickness dimensional accuracy during moisture resistance test

 Manufacturing method

 Surface condition (μπι) Example 1 No change (no birch) 20 ± 1 Cu coating layer + Ni plating Comparative example 1 After 100 hours 鲭 25 ± 2 Electroless Cu plating + Ni plating Comparative example 2 After 300 hours Microscopic mackerel 30 ± 10 Conductive resin layer + Ni plating Comparative example 3 Minute after 350 hours 鲭 27 ± 10 Conductive coating layer + Ni plating

Example 2

Ndl2at% prepared by the rapid solidification method, Fe77at%, B6at%, and kneaded to an epoxy resin 2 wt% to the alloy powder having an average particle size 150μπι having the composition Co5at%, after compression molding at a pressure of 7 ton / cm ² Cure at 170 ° C for 1 hour, outer diameter 26mm x inner diameter

A ring-shaped bonded magnet having a size of 24 mm and a height of 5 mm was produced. The properties of the obtained bonded magnet were Br6.8 kG, iHc9.1 kOe, and (BH) max9.2 MGOe.

After the resulting charged with A1 ₂ 0 ₃ based spherical barrel stones having an average diameter of 3mm magnet 100 Ke (200 g) to the vibration barrel volume 20Z, modified surface by A1 ₂ 0 ₃ powder having a particle size of about Ιμιη 50% of the barrel volume was injected with a vegetable medium consisting of walnut seeds with a diameter of about lmm, and the surface was polished by a dry method with an amplitude of 20 mm for 120 minutes, and the holes were sealed and smoothed.

Then, a bonded magnet was put in a vibrating barrel, and the atmosphere (in iAr gas, using a short cylindrical Cu piece with a diameter of lmm and a length of lmm, a dry barrel with a vibration frequency of 70Mz and a vibration amplitude of 3mm, was polished, Formed conductive coating layer Resin surface of Cu flakes, sealing The indentation depth at the hole was about 0.7μπι, and the coating thickness on the magnetic powder surface was Ο.ΐμπι. The processing conditions for barrel polishing were as follows: a 3.5 W capacity barrel, 50 bonded magnets (apparent capacity 0.15, weight 100 g) and Cu pieces of the above dimensions (apparent capacity 2kg, weight 10 kg) were charged into the barrel. The charge was 60% of the barrel volume and the treatment was performed for 3 hours at an amplitude of 20 mm.

 Thereafter, cleaning was performed, and electric Ni plating was performed by a hook plating method. The film thickness after plating was 21 μιη on the inner diameter side and 23 μπι on the outer diameter side. The resulting ring-shaped bonded magnet was subjected to an environmental test (moisture resistance test) at 80 ° C and a relative humidity of 90% for 800 hours. Table 3 shows the properties of the magnet before and after the moisture resistance test, and Table 4 shows the surface condition results and the film thickness dimensional accuracy during the humidity resistance test.

The conditions for electric Ni plating were as follows: current density: 2 A / dm ² , plating time: 60 minutes, pH: 4.2, bath temperature: 55 ° C; plating solution composition: nickel sulfate 240 g, nickel chloride 45 g / l, nickel carbonate appropriate amount (pH adjustment), the amount of boric acid was 30 g / rt '.

 Comparative Example 4

 The ring-shaped bonded magnet obtained in the same manner as in Example 2 was washed, subjected to the same sealing and surface smoothing treatment as in Example 2, washed, and electroless copper-plated. The plating thickness was 5μιη. After the electroless copper plating, Ni plating was performed under the same conditions as in Example 2. The obtained ring-shaped bonded magnet was subjected to an environmental test (moisture resistance test) under the same conditions as in Example 2. The results and film thickness dimensional accuracy (moisture resistance test) were performed. Tables 3 and 4 show the results.

 The conditions for the electroless copper plating were a plating time of 20 minutes, a pH of 11.5, and a bath temperature of 20 ° C. The composition of the plating solution was 29 gl of copper sulfate, 25 g of sodium carbonate, 140 g of tartrate, 40 g of sodium hydroxide, 37% formaldehyde was 150πιΓϋ.

 Comparative Example 5

After washing the ring-shaped bonded magnet obtained in the same manner as in Example 2, a phenol resin and Ni powder were mixed and applied under the following conditions to form a conductive resin film of ΙΟμπι. The magnet and the 5 mm copper ball were charged into a barrel at 60% of the barrel volume, and smooth polishing was performed by barrel polishing at an amplitude of 20 mm for 60 minutes.

 Thereafter, Ni plating was performed under the same conditions as in Example 2. The obtained ring-shaped bond magnet was subjected to an environmental test (moisture resistance test) under the same conditions as in Example 2. The results and film thickness dimensional accuracy (moisture resistance test) were performed. Tables 3 and 4 show the results.

 The conductive film treatment condition was a treatment time of 30 minutes, and the composition of the treatment solution was phenol resin.

5 wt%, 5 wt% of Ni powder (particle diameter 0.7 μπι or less), and 90 wt% of MEK (methyl ethyl ketone).

 As shown in Table 4, in Comparative Example 4, spots were observed after about 700 hours, and in Comparative Example 5, spots were observed after 600 hours. In contrast, Example 2 did not show any spots observed under a microscope at 30 × magnification even after 800 hours.

 ,, (Magnetic properties after material rise) -Magnetic properties after moisture resistance test) Degradation rate of magnetic properties (%) = ―-"; X 100

(Magnetic characteristics of material rise) Table 4

Example 3

 In the same manner as in Example 1, a ring-shaped bonded magnet having an outer diameter of 25 mm, an inner diameter of 23 mm and a height of 3 mm was produced. The properties of the obtained bonded magnet were Br6.9 kG, iHc9.1 kOe, and (BH) max9.3 MGOe.

 The obtained bonded magnet was placed in a vibration barrel, and dry barrel polishing was performed using a short cylindrical Sn piece having a diameter of 2 mm and a length of 1 mm to form a conductive coating layer of Sn fine particles. The indentation depth of the Sn particles on the resin surface was about 0.9μπι, and the coating thickness on the magnetic powder surface was 0.4μπι. The processing conditions for barrel polishing are the same as in Example 1.

 After that, cleaning was performed, electro-Cu plating was performed by the trap plating method, and then electric Ni plating was performed. The film thickness after plating was 22 μπι on the inner diameter side and 23 μιη on the outer diameter side. The resulting ring-shaped bonded magnet was subjected to an environmental test (moisture resistance test) at 80 ° C and a relative humidity of 90% for 500 hours. Table 5 shows the properties of the magnet before and after the moisture resistance test, and Table 6 shows the surface condition results and the film thickness dimensional accuracy during the moisture resistance test.

The conditions for the electro-Cu plating were a current density of 2.5 A / dm2, a plating time of 5 minutes, a pH of 10, and a bath temperature of 40 ° C. The composition of the plating solution was 20 g of copper and 10 g of free cyanide / nOg / n. In addition, the conditions of the electric Ni plating are the same as those in the first embodiment. Example 4

 A ring-shaped bonded magnet obtained in the same manner as in Example 3 was put in a vibration barrel, and a dry barrel treatment was performed using a cylindrical Zn piece having a diameter of lmm and a length of 2 mm to form a conductive coating layer of Zn fine particles. . The indentation depth of the Zn particles on the resin surface was about 0.8μπι, and the coating thickness on the magnetic powder surface was 0.2μπι. The processing conditions for barrel polishing were the same as in Example 1.

 Thereafter, Cu and Ni plating were performed under the same conditions as in Example 3. The resulting ring-shaped bonded magnet was subjected to an environmental test (moisture resistance test) at 80 ° C and a relative humidity of 90% for 500 hours. Table 5 shows the properties of the magnet before and after the moisture resistance test, and Table 6 shows the surface condition results and the film thickness dimensional accuracy during the moisture resistance test.

 Example 5

 A ring-shaped bonded magnet obtained in the same manner as in Example 3 was placed in a vibration barrel, and a dry barrel treatment was performed using a cylindrical Pb piece having a diameter of lmm and a length of lmm to form a conductive coating layer of Pb fine particles. The press-in depth of the Pb particles on the resin surface was about 0.9μπι, and the coating thickness on the magnetic powder surface was 0.6μπι. The processing conditions for barrel polishing were the same as in Example 1.

 Thereafter, Cu and Ni plating were performed under the same conditions as in Example 3. The resulting ring-shaped bonded magnet was subjected to an environmental test (moisture resistance test) at 80 ° C and a relative humidity of 90% for 500 hours. Table 5 shows the properties of the magnet before and after the moisture resistance test, and Table 6 shows the surface condition results and the film thickness dimensional accuracy during the moisture resistance test.

 Comparative Example 6

After washing the ring-shaped bonded magnet obtained in the same manner as in Example 3, electroless copper plating was performed. The plating thickness was 5 μπι. After the electroless copper plating, Cu and Ni plating were performed under the same conditions as in Example 3. The resulting ring-shaped bonded magnet was subjected to an environmental test (moisture resistance test) at 80 ° C and a relative humidity of 90% for 500 hours. Before and after the humidity test Table 5 shows the characteristics, and Table 6 shows the results of surface conditions and the dimensional accuracy of the film thickness during the moisture resistance test. The conditions for the electroless copper plating were the same as in Comparative Example 1.

 Comparative Example 7

 After washing the ring-shaped bonded magnet obtained in the same manner as in Example 3, a phenol resin and Ni powder were mixed to form a conductive film having a thickness of μμηη. After the treatment, Cu and Ni plating were performed under the same conditions as in Example 3. The resulting ring-shaped bonded magnet was subjected to an environmental test (moisture resistance test) at 80 ° C and a relative humidity of 90% for 500 hours. Table 5 shows the properties of the magnet before and after the moisture resistance test, and Table 6 shows the surface condition results and the film thickness dimensional accuracy during the moisture resistance test. The conductive film treatment conditions were the same as in Comparative Example 2.

 Comparative Example 8

After washing the ring-shaped bonded magnet obtained in the same manner as in Example 3, forming a phenol resin layer as an adhesive layer in advance by a dipping method, and adhering Ag powder (particle diameter 0.7 μπι or less) to the surface Then, a conductive coating layer having a thickness of 7 μπι was formed using a vibration barrel. After the vibration barrel treatment, Cu and Ni plating were performed under the same conditions as in Example 3. The obtained ring-shaped bonded magnet was subjected to an environmental test (moisture resistance test) at 80 ° C and a relative humidity of 90% for 500 hours. Table 5 shows the properties of the magnet before and after the moisture resistance test, and Table 6 shows the surface condition results and the film thickness dimensional accuracy during the moisture resistance test. The vibration barrel treatment conditions were the same as in Comparative Example 3.

Moisture resistance test ¾? ΒΪί Deterioration rate of magnetic properties after moisture resistance test (%)

Br iHc (BH) max Br iHc (BH) max Br iHc (BH) max

(kG) (kOe) (MGOe) (kG) (kOe) (MGOe) (kG) (kOe) (MGOe) Example 3 6.7 9.0 9.0 6.7 8.9 9.0 2.8 2.2 3.2 Example 4 6.7 9.0 9.0 6.7 8.8 9.0 2.8 3.2 3.2 Example 5 6.7 9.0 9.0 6.6 8.8 8.9 4.4 3.3 4.3 Comparative example 6 6.5 8.7 8.8 5.8 7.6 7.7 15.9 16.5 17.2 Comparative example 7 6.5 8.9 8.9 6.2 8.4 8.5 10.1 7.7 8.6 Comparative example 8 6.5 8.9 9.0 6.2 8.5 8.5 10.1 6.6 8.6

(Magnetic characteristics of the material on the surface)-(Magnetic characteristics after moisture resistance test) Degradation ratio of magnetic characteristics (%) = xioo

(Magnetic characteristics of material rise)

Table 6

As is clear from Tables 5 and 6, in Comparative Example 6 the spotted mackerel was observed after about 130 hours, in Comparative Example 7 250 hours later, and in Comparative Example 8 as well as after about 330 hours. On the other hand, in Example 3, even after 500 hours, there was no point observed under a microscope of 30 times.

 Example 6

 In the same manner as in Example 1, a ring-shaped bonded magnet having an outer diameter of 34 mm, an inner diameter of 31 mm and a height of 8 mm was produced. The properties of the obtained bonded magnet were iiBr6.7kG, iHc9.1kOe, and (BH) max9.1MGOe.

It obtained similar manner as in Example 2 the magnet, and sealing and smoothing treatment with A1 ₂ 0 ₃ based spherical barrel stones having an average diameter of 3mm with a vibrating barrel conditions.

Then, a bonded magnet is inserted in a vibrating barrel, and dry barrel polishing is performed using short cylindrical Sn, Zn, and Pb pieces each having a diameter of lmm and a length of lmm. Was formed. Table 7 shows the depth of press-fitting of the metal particles on the resin surface, the sealing part, and the coating thickness on the magnetic powder surface. The processing conditions for barrel polishing were the same as in Example 2.

 After that, cleaning was performed, and electric Ni plating was performed by the trap plating method, and then Ni plating was performed. The film thickness after plating was 21 μπι on the inner diameter side and 22 μπι on the outer diameter side. The obtained ring-shaped bonded magnet was subjected to an environmental test (moisture resistance test) at 80 ° C and a relative humidity of 90% for 1000 hours. Tables 8 to 9 show the results and the film thickness dimensional accuracy. The conditions for the Cu electroplating and Ni electroplating were the same as in Example 2.

 Comparative Example 9

 After washing the ring-shaped bonded magnet obtained in the same manner as in Example 6, the same sealing and surface smoothing treatment as in Example 6 was performed, followed by cleaning, and then electroless copper plating. The plating thickness was 5 μπι. After electroless copper plating, Cu plating and Ni plating were performed under the same conditions as in Example 6.

 The obtained ring-shaped bonded magnet was subjected to an environmental test (moisture resistance test) under the same conditions as in Example 6. Table 8 shows the properties of the magnet before and after the moisture resistance test, and Table 9 shows the surface condition results and the film thickness dimensional accuracy during the humidity resistance test. The electroless copper plating conditions were the same as in Comparative Example 4.

 Comparative Example 10

 After washing the ring-shaped bonded magnet obtained in the same manner as in Example 6, a phenol resin and Ni powder were mixed and applied to form a conductive resin film of ΙΟμπι, and the magnet and a 5 mm steel ball were placed in a vibration barrel. 60% of the barrel volume was charged, and smooth polishing was performed by barrel polishing at an amplitude of 20 mm for 60 minutes.

Thereafter, Cu plating and Ni plating were performed under the same conditions as in Example 6. The resulting ring-shaped bonded magnet was subjected to an environmental test (moisture resistance test) under the same conditions as in Example 6. Tables 8 to 9 show the results and the film thickness dimensional accuracy. The conductive film treatment conditions were the same as in Comparative Example 5. Table 7

(Magnetic properties of the material on the material)-(Magnetic properties after moisture resistance test) Degradation rate of magnetic properties () = X 100

(Magnetic characteristics of material rise) Film thickness dimensions during moisture resistance test

 Surface condition Accuracy (μπι) Example 6 No change in Sn (no emission) 22 ± 1 Sealing treatment + Sn coating layer + Cu, Ni plating Example 6Zn No change (No emission) 22 ± 1 Sealing treatment + Zn coating layer + Cu, Ni plating Example 6 Pb No change (no emission) 22 ± 1 Sealing treatment + Pb coating layer + Cu, Ni plating Comparative example 9 After 800 hours △ 27 ± 2 Sealing treatment + Electroless Cu + Cu, Ni plating Comparative example 10 After 600 hours 鑌 30 ± 5 Conductive resin layer + Smooth polishing + Cu, Ni plating

As can be seen from Table 9, in Comparative Example 9, spots were observed after about 800 hours, and in Comparative Example 10, spots were observed after 600 hours. In contrast, Example 6 did not show any spots observed under a microscope at 30 × magnification even after 1000 hours.

 Example 7

 In the same manner as in Example 1, a ring-shaped bonded magnet having an outer diameter of 21 mm, an inner diameter of 18 mm and a height of 4 mm was produced. The properties of the obtained bonded magnet are shown in Table 11,

Br6.8kG, iHc9.1kOe, (BH) max9.2MGOe.

 The obtained bonded magnet was placed in a vibration barrel, and dry barrel polishing was performed using short cylindrical Fe, Ni, Co, and Cr pieces having a diameter of 0.7 mm and a length of 0.5 mm to form a conductive coating layer of the metal fine particles. Formed. Table 10 shows the press-fitting depth of the metal particles on the resin surface and the coating thickness on the magnetic powder surface. The processing conditions for barrel polishing are the same as in Example 1.

After that, cleaning was performed, electro-Cu plating was performed by the trap plating method, and then electric Ni plating was performed. The film thickness after plating is 18μπι on the inner diameter side and 21μπι on the outer diameter side. Was. The resulting ring-shaped bonded magnet was subjected to an environmental test (moisture resistance test) at 80 ° C and a relative humidity of 90% for 500 hours. Table 12 shows the properties of the magnet before and after the humidity resistance test, and Table 13 shows the surface condition results and the film thickness dimensional accuracy during the humidity resistance test. The conditions for the Cu plating and the Ni plating are the same as in the first embodiment.

 Comparative Example 11

 After cleaning the ring-shaped bonded magnet obtained in the same manner as in Example 7, electroless copper plating was performed. The plating thickness was 6 μπι. After the electroless copper plating, Cu and Ni plating were performed under the same conditions as in Example 3. The resulting ring-shaped bonded magnet was subjected to an environmental test (moisture resistance test) at 80 ° C and a relative humidity of 90% for 500 hours. Table 12 shows the properties of the magnet before and after the moisture resistance test, and Table 13 shows the surface condition results and the film thickness dimensional accuracy during the moisture resistance test. The conditions for the electroless copper plating were the same as in Comparative Example 1.

 Comparative Example 12

 After washing the ring-shaped bonded magnet obtained in the same manner as in Example 7, a phenol resin and Ni powder were mixed to form a conductive film having a thickness of μμηη. After the treatment, Cu and Ni plating were performed under the same conditions as in Example 7. The resulting ring-shaped bonded magnet was subjected to an environmental test (moisture resistance test) at 80 ° C and a relative humidity of 90% for 500 hours. Table 12 shows the properties of the magnet before and after the moisture resistance test, and Table 13 shows the surface condition results and the film thickness dimensional accuracy during the moisture resistance test. The conductive film treatment conditions were the same as in Comparative Example 2.

 Comparative Example 13

After washing the ring-shaped bonded magnet obtained in the same manner as in Example 7, forming a phenol resin layer as an adhesive layer in advance by a dipping method, and then attaching Ag powder (particle diameter 0.7 μπι or less) to the surface Then, a conductive coating layer having a thickness of 7 μιη was formed using a vibration barrel. After the vibration barrel treatment, Cu and Ni plating were performed under the same conditions as in Example 7. The obtained ring-shaped bonded magnet was subjected to an environmental test (moisture resistance test) at 80 ° C and a relative humidity of 90% for 500 hours. Table 12 shows the properties of the magnet before and after the moisture resistance test, and Table 13 shows the surface condition results and the film thickness dimensional accuracy during the moisture resistance test. The vibration barrel treatment conditions were the same as in Comparative Example 3. Table 10

 Re-magnetic properties on material

Br (kG) iHc (kOe) (BH) ma MGOe

Fe 6.8 9.1 9.2 Application Ni 6.8 9.1 9.2 Example Co 6.8 9.1 9.2

7 Cr 6.8 9.1 9.2 Comparative example 11 6.8 9.1 9.2 Comparative example 12 6.8 9.1 9.2 Comparative example 13 6.8 9.1 9.2 Table 12

(Magnetic properties of the material on the material)-(Magnetic properties after moisture resistance test) Degradation rate of magnetic properties (%) = X 100

(Magnetic characteristics of material rise)

Table 13

As is clear from Tables 10 to 13, in Comparative Example 11 spots were observed after about 130 hours, in Comparative Example 12 after 350 hours, and in Comparative Example 13 also after about 370 hours. On the other hand, in Example 7, even after 500 hours, no point was observed under a microscope of 30 times magnification.

 Example 8

 In the same manner as in Example 1, a ring-shaped bonded magnet having an outer diameter of 29 mm, an inner diameter of 25 mm, and a height of 5 mm was produced. The characteristics of the obtained bonded magnet are shown in Table 15,

Br6.7kG, iHc9.3kOe, (BH) max9.5MGOe.

Similarly obtaining magnet of Example 2 method, the vibration barrel conditions Yore and sealing and smoothing treatment with A1 ₂ 0 ₃ based spherical barrel stones having an average diameter of 3 mm. Next, a bonded magnet was inserted in a vibrating barrel, and dry barrel polishing was performed using short columnar Fe, Ni, Co, and Cr pieces of 0.5 mm in diameter and 0.4 mm in length to form a conductive coating layer of metal particles. . Table 14 shows the depth of press-fitting of the metal particles on the resin surface, the sealing part, and the coating thickness on the magnetic powder surface. The processing conditions for barrel polishing were the same as in Example 2. After that, cleaning was performed, and electric Ni plating was performed by the trap plating method, and then Ni plating was performed. The film thickness after plating was 20 μπι on the inner diameter side and 22 μιη on the outer diameter side. The obtained ring-shaped bonded magnet was subjected to an environmental test (moisture resistance test) at 80 ° C and a relative humidity of 90% for 1000 hours. Tables 16 to 17 show the results and film thickness dimensional accuracy.

 The conditions for the Cu electroplating and Ni electroplating were the same as in Example 2. The zinc displacement treatment conditions were as follows: treatment time: 40 seconds, bath temperature: 22 ° C, liquid resistance: sodium hydroxide 300 g, zinc oxide 40 g / Z, ferric chloride lg / Z, rossel salt 30 g / / Was. The film thickness was Ο.ΟΙμπι.

 Comparative Example 14

 After washing the ring-shaped bonded magnet obtained in the same manner as in Example 8, the same sealing and surface smoothing treatment as in Example 6 was performed, followed by cleaning, and electroless copper plating was performed. The plating thickness was 5 μπι. After electroless copper plating, Cu plating and Ni plating were performed under the same conditions as in Example 8.

 The obtained ring-shaped bonded magnet was subjected to an environmental test (moisture resistance test) under the same conditions as in Example 8. Tables 16 to 17 show the results and the film thickness dimensional accuracy. The electroless copper plating conditions were the same as in Comparative Example 4.

 Comparative Example 15

After washing the ring-shaped bonded magnet obtained in the same manner as in Example 6, a phenol resin and Ni powder were mixed and applied to form a conductive resin film of ΙΟμπι, and the magnet and a 5 mm steel ball were placed in a vibration barrel. 60% of the barrel volume was charged, and smooth polishing was performed by barrel polishing at an amplitude of 20 mm for 60 minutes. Thereafter, Cu plating and Ni plating were performed under the same conditions as in Example 8. The resulting ring-shaped bonded magnet was subjected to an environmental test (moisture resistance test) under the same conditions as in Example 6. Tables 16 to 17 show the results and film thickness dimensional accuracy. The conductive film treatment conditions were the same as in Comparative Example 5.

 Table 14

 Material rise

Br iHc (BH) max

 (kG) (kOe) (MGOe)

 Example 8 Fe 6.9 9.3 9.5

 Example 8 Ni 6.9 9.3 9.5

 Example 8 Co 6.9 9.3 9.5

 Example 8 Cr 6.9 9.3 9.5

Comparative Example 14 6.9 9.3 9.5 Comparative Example 15 6.9 9.3 9.5 Table 16

f _a (Magnetic properties of the material on the material)-(Magnetic properties after moisture resistance test) Degradation rate of magnetic properties (%) = X 100

(Magnetic characteristics of the material on top)

Table 17

Table 17 shows that Comparative Example 14 had spotting after about 700 hours, and Comparative Example 15 also had spotting after 550 hours. In contrast, Example 8 did not show any spots observed under a microscope at 30 × magnification even after 800 hours.

 Example 9

 In the same manner as in Example 1, a ring-shaped bond magnet having an outer diameter of 20 mm, an inner diameter of 17 mm and a height of 6 mm was produced. The properties of the obtained bonded magnet were iiBr6.9 kG, iHc9.4 kOe, and (BH) max9.6MGOe.

The resulting bonded magnet was placed in a vibrating barrel, and dry barrel polishing was performed using a short cylindrical A1 piece having a diameter of 0.8 mm and a length of lmm to form a conductive coating layer of A1 fine particles. The coating depth of the A1 fine particles on the resin surface was about 0.9μπι, and the coating thickness on the magnetic powder surface was 0.5μπι. The processing conditions for barrel polishing are the same as in Example 1. After washing and zinc substitution, electric Ni plating was carried out by the trap plating method. The film thickness after plating was 19 μπι on the inner diameter side and 21 μπι on the outer diameter side. The obtained ring-shaped bonded magnet was subjected to an environmental test (moisture resistance test) at 80 ° C and a relative humidity of 90% for 500 hours. Table 18 shows the properties of the magnet before and after the humidity resistance test, and Table 19 shows the surface condition results and the film thickness dimensional accuracy during the humidity resistance test. In addition, the conditions of the electric Ni plating are the same as those in the first embodiment.

 Comparative Example 16

 After washing the ring-shaped bonded magnet obtained in the same manner as in Example 9, electroless copper plating was performed. The plating thickness was 6 μπι. After the electroless copper plating, Cu and Ni plating were performed under the same conditions as in Example 3. The obtained ring-shaped bonded magnet was subjected to an environmental test (moisture resistance test) at 80 ° C and a relative humidity of 500 hours. Table 18 shows the properties of the magnet before and after the moisture resistance test, and Table 19 shows the surface condition results and the film thickness dimensional accuracy during the moisture resistance test. The conditions for the electroless copper plating were the same as in Comparative Example 1.

 Comparative Example 17

 After washing the ring-shaped bonded magnet obtained in the same manner as in Example 9, a phenolic resin and Ni powder were mixed to form a conductive film having a thickness of μππι. After the treatment, Ni plating was performed under the same conditions as in Example 9. The resulting ring-shaped bonded magnet was subjected to an environmental test (moisture resistance test) at 80 ° C and a relative humidity of 90% for 500 hours. Table 18 shows the properties of the magnet before and after the moisture resistance test, and Table 19 shows the surface condition results and the film thickness dimensional accuracy during the moisture resistance test. The conductive film treatment conditions were the same as in Comparative Example 2.

 Comparative Example 18

After washing the ring-shaped bonded magnet obtained in the same manner as in Example 9, forming a phenol resin layer as an adhesive layer in advance by a dipping method, and then attaching Ag powder (particle diameter 0.7 μπχ or less) to the surface Then, a conductive coating layer having a thickness of 7 μπι was formed using a vibration barrel. After the vibration barrel treatment, Ni plating was performed under the same conditions as in Example 9. The resulting ring-shaped bonded magnet was subjected to an environmental test (moisture resistance test) at 80 ° C and a relative humidity of 90% for 500 hours. Its moisture resistance test Table 18 shows the properties of the magnets before and after the test, and Table 19 shows the surface condition results and film thickness dimensional accuracy during the moisture resistance test. The vibration barrel treatment conditions were the same as in Comparative Example 3. Table 18

 丄 ,, (Magnetic properties of material on the material-(Magnetic properties after humidity resistance test) Magnetic property deterioration rate =; X 100

(Magnetic characteristics of the material on top)

Table 19

As is clear from Tables 18 to 19, spots were observed after about 120 hours in Comparative Example 16, and spotted spots were observed after about 270 hours in Comparative Example 17 and about 300 hours in Comparative Example 18. On the other hand, in Example 9, even after 500 hours, there were no spots observed under a microscope at 30 × magnification.

 Example 10

 In the same manner as in Example 1, a ring-shaped bonded magnet having an outer diameter of 36 mm, an inner diameter of 33 mm and a height of 3 mm was produced. The properties of the resulting bonded magnet were Br 6.7 kG, iHc 9.2 kOe, and (BH) max 9.5 MGOe.

After the resulting charged with A1 ₂ 0 ₃ system Spherical barrel stones having an average diameter of 4mm magnets 220 Ke to vibration barrel volume 20Z, the surface was modified by A1 ₂ 0 ₃ powder having a particle size of about 2μπι A vegetable medium consisting of walnut nuts with a diameter of about 2 mm was charged at 50% of the barrel volume, the surface was polished by a dry method for 150 minutes, and the holes were sealed and smoothed.

The obtained bonded magnet is placed in a vibrating barrel, and dry barrel polishing is performed using a short cylindrical A1 piece with a diameter of 0.5 mm and a length of 0.7 mm to form a conductive coating layer of A1 fine particles. Done. The press-fitting coating depth of the Al particles on the resin surface was about 1.1 μπι, and the coating thickness on the magnetic powder surface was 0.6 μπι. The processing conditions for barrel polishing are the same as in Example 1.

 After washing and zinc substitution, electric Ni plating was carried out by the trap plating method. The film thickness after plating was 17 μπη on the inner diameter side and 19 μιη on the outer diameter side. The obtained ring-shaped bonded magnet was subjected to an environmental test (moisture resistance test) at 80 ° C and a relative humidity of 90% for 500 hours. Table 20 shows the properties of the magnet before and after the humidity resistance test, and Table 21 shows the surface condition results and the film thickness dimensional accuracy during the humidity resistance test.

 The conditions for the Cu electroplating and Ni electroplating were the same as in Example 2. The treatment conditions for the zinc displacement treatment were a treatment time of 40 seconds, a bath temperature of 22 ° C., and a liquid composition of 300 g of sodium hydroxide, 40 g of zinc oxide, ferric chloride lg, and rossel salt 30 g /. The film thickness was Ο.ΟΙμπι.

 Comparative Example 19

 After washing the ring-shaped bonded magnet obtained in the same manner as in Example 10, the same sealing and surface smoothing treatment as in Example 10 was performed, followed by cleaning, and then electroless copper plating was performed. The plating thickness was 6 μπι. After the electroless copper plating, Ni plating was performed under the same conditions as in Example 10. The resulting ring-shaped bonded magnet was subjected to an environmental test (moisture resistance test) at 80 ° C and a relative humidity of 90% for 1000 hours. Table 20 shows the properties of the magnet before and after the humidity resistance test, and Table 21 shows the surface condition results and film thickness dimensional accuracy during the humidity resistance test. The conditions for electroless copper plating were the same as in Comparative Example 4.

 Comparative Example 20

 After washing the ring-shaped bonded magnet obtained in the same manner as in Example 10, a phenol resin and Ni powder were mixed under the following conditions to form a 12 μπι conductive resin film, and the above magnet and 2 mm steel were placed in a vibration barrel. The ball was charged to 70% of the barrel volume and smooth-polished by barrel polishing for 90 minutes.

Thereafter, Ni plating was performed under the same conditions as in Example 10. An environmental test (moisture resistance test) was performed on the obtained ring-shaped magnet at 80 ° C and a relative humidity of 90% for 1000 hours. Table 20 shows the properties of the magnet before and after the moisture resistance test, and Table 21 shows the results of the surface condition and the film thickness accuracy during the moisture resistance test. The conductive film treatment conditions were the same as in Comparative Example 5. Table 20

(Magnetic property after material rise)-(Magnetic property after moisture resistance test) Magnetic property deterioration rate (%) = -—— ~~ —— X 100

(Magnetic characteristics of the material on top)

Table 21

As is clear from Tables 20 to 21, Comparative Example 19 showed spotting after about 750 hours, and Comparative Example 20 showed spotting after 680 hours, whereas Example 10 showed 1000 hours. Even afterwards, there was no point 認 め observed with a microscope at a magnification of 30 ×.

Industrial applicability

The present invention relates to a dry method using a porous R-Fe-B bonded magnet as a medium by using a mixture of an abrasive and a vegetable medium or a mixture of an abrasive and a vegetable medium modified with an inorganic powder. By applying barrel polishing in the above, the polishing powder, the inorganic powder and the polishing dust can be fixed and sealed in the pores of the R-Fe-B-based bonded magnet with the oil and fat content of the vegetable medium, At the same time, surface smoothing treatment can be performed and modified, and this R-Fe-B based bonded magnet can be formed with a barrel device using amorphous A1 such as spherical, massive or needle-like (one wire) of required dimensions. Barrel polishing is performed by a dry method, and the crushed A1 fine particles are press-fitted onto the resin surface and the sealing portion of the bonded magnet surface, and the magnetic powder surface is coated with the A1 fine particles to obtain R-Fe-B. After forming an A1 coating film on the surface of the bonded magnet, By performing a zinc substitution treatment on the surface of the Al coating layer, a dense and pinhole-free electrolytic plating layer can be formed, and an R-Fe-B based bond magnet having extremely excellent corrosion resistance can be obtained.

Claims

The scope of the claims

1. Metal particles were press-fitted and coated on the resin surface and pores constituting the surface of the R-Fe-B-based bonded magnet, and were formed by coating metal particles on the surface of magnetic powder constituting the surface. A highly corrosion-resistant R-Fe-B-based bonded magnet having a metal-coated surface of the magnet surface and an electrolytic plating layer on the outermost surface via the metal-coated surface.

 2. The pores formed on the surface of the R-Fe-B-based bonded magnet are adhered and sealed with abrasive powder and abrasive debris from the bonded magnet, or further, inorganic powder with the oils and fats of the vegetable medium. A metal particle is press-fitted and coated on the resin surface and the sealing portion constituting the magnet surface, and a metal-coated surface of the magnet surface and the metal coating is formed by press-fitting the metal particle on the magnetic powder surface constituting the magnet surface. Highly corrosion resistant R-Fe-B bonded magnet with an electrolytic plating layer on the outermost surface through the surface.

 3. In claim 1 and claim 2, the metal particles are

 食 11,811 11 1), 〇 (1,111 11, ^ 6: ^, 00,1 and their alloys; high corrosion resistance R-Fe-B bonded magnets.

 4. The high corrosion-resistant R-Fe-B-based magnet according to claim 1 or 2, wherein the metal-particle press-fitting coating layer formed on the resin surface and the pores has a thickness of 0.1 μπι to 2 μπι.

 5. The high corrosion resistant R-Fe-B-based bonded magnet according to claim 1 or 2, wherein the thickness of the metal fine particle coating layer coated on the surface of the magnetic powder is Ι.Ομπι or less.

 6. The high corrosion resistant R-Fe-B-based bonded magnet according to claim 5, wherein the thickness of the Cu, Fe, Ni, Co, Cr and alloy coating layer coated on the surface of the magnetic powder is 0.2 µιη or less.

7. In claim 1 or claim 2, when the metal particles are A1 and its alloy, high corrosion resistance R having an electrolytic plating layer via Zii layer formed on A1 on the magnet surface and its alloy coating surface -Fe-B bonded magnet.

8. Load the R-Fe-B bonded magnet surface with the R-Fe-B bonded magnet and irregular shaped metal particles in the barrel device, and perform barrel polishing by dry method. Pressing and covering metal particles crushed on the resin surface and the pores, covering the metal particles on the surface of the magnetic powder constituting the magnet surface, forming a metal coating layer on the magnet surface, A method for producing a high corrosion resistant R-Fe-B bonded magnet that forms an electrolytic plating layer by applying electrolytic plating to the outermost surface through a conductive metal coating layer.

 9. Using a mixture of a vegetable medium or an abrasive with a surface modified with a vegetable medium or inorganic powder as a media, R-Fe-B bonded magnets are barrel-polished by a dry method, and are polished as described above. The material powder and the grinding dust of the bonded magnet or the inorganic powder are fixed to the pores of the R-Fe-B-based bonded magnet with the fat and oil of the vegetable medium, and the surface is reformed by smoothing the surface. After that, the bonded magnet and the irregular shaped metal particles are charged into a barrel device, barrel-polished by a dry method, and the crushed metal particles are pressed into the resin surface of the magnet and the sealing portion. By coating the surface of the R-Fe-B bonded magnet by coating it with metal fines on the surface of the magnetic powder, it provides an electrolytic plating layer on the outermost surface. Manufacturing method of Fe-B bonded magnet.

 10. In claim 8 or claim 9, the metal particles are

 A method for producing a high corrosion resistant R-Fe-B bonded magnet which is Cu, Sn, Zn, Pb, Cd, In, Au, Ag, Fe, Ni, Co, Cr, Al and alloys thereof.

 11. In claim 8 or claim 9, when the metal particles are A1, a high corrosion resistance R having an electrolytic plating layer on the A1 coated surface of the magnet surface via a Zn layer formed by zinc substitution treatment method R -Fe-B bonded magnet manufacturing method.

 12. In claim 8 or claim 9, the size of the irregular shaped metal particles is

0.1 mm or more: A method for producing a high corrosion-resistant R-Fe-B bonded magnet that is LOmm spherical, massive, or needle-like.

13. In claim 12, the size of the irregular shaped Cu, Fe, Ni, Co, Cr particles is

 A method for producing 0.1 mm to 5 mm spherical, massive, or needle-shaped highly corrosion-resistant R-Fe-B-based bonded magnets.

 14. The method for producing a highly corrosion-resistant R-Fe-B-based bonded magnet according to claim 8 or 9, wherein the metal fine particles crushed by barrel polishing have a major axis of 5 μπι or less.

 15. The high corrosion resistance R-Fe- according to claim 8 or claim 9, wherein the barrel is polished by using a rotating, vibrating or centrifugal barrel with a volume ratio of magnet and metal fine particles (magnet / metal fine particles) of 3 or less. Manufacturing method of B type bonded magnet.

 16. The method for producing a high corrosion resistant R-Fe-B-based bonded magnet according to claim 9, wherein the abrasive is an abrasive stone or a metal ball obtained by baking and solidifying an inorganic powder.

 17. The method for producing a highly corrosion-resistant bonded R-Fe-B-based magnet according to claim 9, wherein the vegetable medium is vegetable peel, sawdust, fruit shell, and corn core.

 18. The high corrosion-resistant R-Fe-B bonded magnet according to claim 8 or 9, wherein the R-Fe-B bonded magnet and the metal particles are barrel-polished by a dry method in an inert gas atmosphere. Manufacturing method.