JPH06114739A - Electrodeposition grinding wheel - Google Patents

Abstract

PURPOSE:To prolong the life of a grinding wheel by forming an electrolytic plating layer and an electroless plating layer of a specified constitution in the abrasive grain layer forming surface of a base metal, embedding large diameter super abrasive grains of a specified means grain size in both the layers, and further fixing a large number of the grains in a monolayer state along the abrasive grain layer forming surface, in the electrodeposition grinding wheel for grinding. CONSTITUTION:An electrolytic plating layer 12 and an electroless plating layer 14 are successively formed in a uniform thickness further with the synthetic thickness 0.2-0.8 times of a mean grain size, on an abrasive grain layer forming surface 10A of a conductor-made base metal 10. The electroless plating layer 14 is formed of a heat hardened Ni-B system alloy by containing 1-20wt.% P and 0.2-15wt.% heat hardened Ni-P system alloy or B. Furtherm hard small diameter particles 16 of 5mum or less mean grain size of one kind or more, selected from a super abrasive grain, SiC, Si3N4, Al2O3, are uniformly 5 to 35vol.% dispersed. Many large diameter super abrasive grains 18 of 50mum or more mean grain size are buried in both the layers 12, 14 and fixed in a monolayer state along the abrasive grain layer forming surface 10A.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrodeposition grindstone used for various kinds of grinding and cutting, and more particularly to an improvement for extending the life of the grindstone.

[0002]

2. Description of the Related Art In this type of electrodeposition grindstone, superabrasive grains such as diamond or CBN are fixed in a single layer on a surface of a base metal on which an abrasive grain layer is formed by a Ni plating layer formed by an electrolytic plating method. However, the thickness of the metal plating layer tends to be uneven due to the shape of the surface on which the abrasive layer is formed, the particle size of the abrasive particles, and the uneven distribution of the abrasive particles. The Ni plating layer obtained by electrolytic plating is Due to the fact that it is soft, etc., it has the drawbacks that it has a small abrasive grain holding force, and the abrasive grains fall off relatively early, resulting in a short life.

In order to improve the above drawbacks, for example, Japanese Patent Laid-Open No.
Japanese Patent Laid-Open No. 3-221977 proposes an electrodeposition grindstone as shown in FIG. 2, and this grindstone is produced through the following steps. First, a Ni undercoat layer 2 is formed by electrolytic plating on the abrasive layer forming surface 1A of the base metal 1, and the superabrasive particles 3 are formed thereon.
While dispersing, the Ni electrolytic plating layer 4 is formed by electrolytic plating and the superabrasive grains 3 are temporarily fixed.

Next, electroless plating is performed to deposit a Ni--P alloy layer 5 between these temporarily fixed superabrasive grains 3,
The super-abrasive grains 3 are embedded to a predetermined depth and further heat-treated to harden the Ni-P alloy layer 5.

According to this electrodeposition grindstone, the entire thickness of the metal plating layers 4 and 5 holding the superabrasive grains 3 becomes uniform, the variation in the abrasive grain holding force can be corrected, and the Ni-plating by heat treatment.
Since the -P alloy layer 5 is hardened, the abrasive grain holding power is improved as a whole, wasteful removal of abrasive grains is reduced, and the life of the grindstone can be extended.

[0006]

However, even in the case of a grindstone having a Ni-P alloy layer having an increased abrasive grain holding force as described above, when the hard-to-cut work material is ground, the abrasive grains are However, there was a drawback that the grinding wheel life was not extended as expected. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an electrodeposited grindstone that reduces wasteful removal of abrasive grains and has a long grindstone life until sharpness is reduced.

[0007]

The present invention has been made to solve the above problems. First, the first electrodeposition grindstone according to the present invention is electrolytic plating on a surface of a base metal on which an abrasive grain layer is formed. Layer and electroless plating layer are formed in order, and the average particle diameter is 50 μm embedded in these electroplating layer and electroless plating layer.
A large number of the large-diameter superabrasive grains described above are fixed in a single layer along the surface where the abrasive grain layer is formed, and the electroless plating layer has P of 1
.About.20 wt% and is composed of a heat-hardened Ni alloy, and in this electroless plating layer, superabrasive grains and Si are contained.
5 to 35v of hard small-diameter particles having an average particle diameter of 5 μm or less of one kind or two kinds or more selected from C, Si ₃ N ₄ and Al ₂ O ₃
ol% is uniformly dispersed.

On the other hand, in the second electrodeposition grindstone according to the present invention, the electrolytic plating layer and the electroless plating layer are sequentially formed on the surface of the base metal on which the abrasive grain layer is formed. Embedded therein, a large number of large-diameter superabrasive grains having an average grain size of 50 μm or more are fixed in a single layer along the abrasive grain layer forming surface, and the electroless plating layer contains B of 0.2 to 15 w.
composed of a Ni alloy containing t% and heat-hardened,
Moreover, super-abrasive grains, SiC, Si are contained in the electroless plating layer.
One or more selected from ₃ N ₄ and Al ₂ O ₃ are characterized in that hard small-diameter particles having an average particle diameter of 5 μm or less are uniformly dispersed in an amount of 5 to 35 vol%.

In any of the above cases, it is preferable that the Ni alloy forming the electroless plating layer further contains 0.5 to 30 wt% of one or more elements selected from W, Mo and Re. Further, the thickness of the electroless plating layer is 0.1 to 0.7 times the average particle size of the large-diameter superabrasive grains, and the total thickness of the electrolytic plating layer and the electroless plating layer, It is desirable that the average grain size of the large-diameter superabrasive grains be 0.2 to 0.8 times.

[0010]

In the electrodeposition grindstone according to the present invention, the individual large-diameter superabrasive grains that contribute to the grinding of the work material are Ni-P alloy or Ni.
-Supported by an electroless plating layer that is made of B-based alloy and has a high hardness, and the electroless plating layer has a thickness of 5 μm.
Since the small-diameter superabrasive particles of less than m are uniformly dispersed, the small-diameter superabrasive particles reduce the frequency of contact between the electroless plating layer and the work material to reduce the wear rate of the electroless plating layer, and particles. The dispersion has the effect of increasing the deformation resistance of the electroless plating layer.

Therefore, in this electrodeposition grindstone, the holding power of the large-diameter superabrasive grains by the electroless plating layer is remarkably high, and further, the electroless plating layer is hard to be worn and the reduction rate of the holding force of the abrasive grains is small. Even when the material is ground, the large-diameter superabrasive grains that serve as the cutting edge are less likely to be wasted, and good sharpness can be maintained for a long period of time.

Further, since the electrolytic plating layer which is softer than the electroless plating layer is formed between the electroless plating layer and the abrasive grain layer forming surface of the base metal, the hard electroless plating layer and the base metal are The effect of alleviating the thermal stress generated during the heat treatment is obtained, and there is little risk of peeling of the abrasive grain layer even when grinding with a large amount of heat generation.

[0013]

EXAMPLE FIG. 1 is an enlarged sectional view showing an example of an electrodeposition grindstone according to the present invention. Reference numeral 10 in the figure is a base metal having at least its surface formed of a conductor. This base metal 10
The shape of is not limited, and may be any shape conventionally used such as a cup type, a wheel type, and a full type. Further, as long as the abrasive grain layer forming surface 10A is made of a conductor, the inside may be a non-conductor.

An electrolytic plating layer 12 and an electroless plating layer 14 are sequentially formed on the abrasive grain layer forming surface 10A to have a uniform thickness. The electrolytic plating layer 12 and the electroless plating layer 14 are formed in this order.
Embedded in the surface, the large-diameter superabrasive grains 18 are formed on the abrasive grain layer forming surface 10A.
Many are fixed in a single layer along. Further, a large number of small-diameter superabrasive grains 16 are uniformly dispersed in the electroless plating layer 14.

The electroplating layer 12 is formed of Ni or a Ni alloy, and particularly has a Co content of 10 to 60 wt.
%, The Ni-Co alloy has a high hardness after heat treatment and is suitable. When the Co content is less than 10 wt%, the heat resistance and fatigue resistance are lowered and the abrasive grain holding power is lowered, while 60 wt%
The larger the cost, the higher the cost because Co is expensive.

On the other hand, the electroless plating layer 14 has P of 1 to 2
Ni-P alloy containing 0 wt% and heat-hardened, or Ni-P alloy containing 0.2 to 15 wt% B and heat-hardened.
It is formed of a B-based alloy. In the case of a Ni-P alloy, if the P content is less than 1 wt%, sufficient hardness cannot be obtained, and if it is more than 15 wt%, the toughness decreases and the abrasive grain holding force decreases. Further, in the case of a Ni-B alloy, if the content of B is less than 0.2 wt%, sufficient hardness cannot be obtained, and if it is more than 15 wt%, the smoothness of the plating is deteriorated or the plating layer is formed. The problem of becoming brittle arises.

Regardless of whether the electroless plating layer 14 is a Ni-P type alloy or a Ni-B type alloy, the electroless plating layer 14 contains one or two kinds selected from W, Mo and Re. It is desirable that the above elements are contained in a total amount of 0.5 to 30 wt%. In that case, if the total content of W, Mo and Re is less than 0.5 wt%, a sufficient hardness improving effect cannot be obtained, and if it exceeds 30 wt%, the brittleness of the electroless plating film increases, and conversely the abrasive grains This causes a problem that the holding power is lowered.

The average diameter of the small-diameter superabrasive grains 16 must be 5 μm or less, and more preferably 1 to 3 μm. If it is larger than 5 μm, the effect of improving the strength, hardness and deformation resistance of the electroless plating layer 14 due to particle dispersion becomes insufficient. The content of the small-diameter superabrasive grains 16 in the electroless plating layer 14 is preferably 5 to 35 vol% and 5 vo
If it is less than 1%, the effect of improving the strength of the electroless plating layer 16 is insufficient, and if it is more than 35 vol%, the strength of the electroless plating layer 16 is lowered.

Instead of superabrasive grains, SiC, Si ₃
The same effect can be obtained by using one or two or more kinds of hard small-diameter particles having an average particle diameter of 5 μm or less selected from N ₄ and Al ₂ O ₃ .

The average particle size of the large-diameter superabrasive particles 18 is required to be 50 μm or more, preferably 80 to 300 μm. When the average particle size of the large-diameter superabrasive particles 18 is less than 50 μm, the protrusion amount of the large-diameter superabrasive particles 18 is secured sufficiently large,
It becomes difficult to sufficiently increase the holding power of the large-diameter superabrasive grains 18, and it is difficult to obtain the effect of the present invention. Also, large-diameter superabrasive grains 18
It is preferable that the area content of the whole abrasive grain layer is about 30 to 65%. If it deviates from this range, it becomes difficult to achieve both sharpness and life in any case.

The thickness T1 of the electrolytic plating layer 12 is preferably 0.1 to 0.7 times the average particle size of the large-diameter superabrasive particles 18. If less than 0.1 times, electroless plating layer 14 and base metal 10
And the stress relaxation effect between the two becomes insufficient, the electroless plating layer 14 may peel off from the base metal 10 at the time of temperature rise, and it is difficult to temporarily fix the large-diameter superabrasive grains 18 in the manufacturing method described later. become. Further, the thickness T1 is a large-diameter superabrasive grain 1
If the average grain size of No. 8 is larger than 0.7 times, the thickness of the electroless plating layer 14 is relatively reduced, and the abrasive grain holding power is reduced.

Electrolytic plating layer 12 and electroless plating layer 1
4 has a total thickness T2 of 0.
It is desirable to be 2 to 0.8 times. If it is less than 0.2 times, the abrasive grain holding power is insufficient, and if it is more than 0.8 times, the large-diameter super abrasive grain 1
The protrusion amount of 8 is insufficient and the sharpness is reduced. It is more preferably 0.5 to 0.8 times.

In this embodiment, the electrolytic plating layer 12 is formed directly on the abrasive grain layer forming surface 10A of the base metal 10. However, instead of this, Ni is formed on the abrasive grain layer forming surface 10A of the base metal 10. Alternatively, a base plating layer made of a Ni alloy or the like (in this case, it becomes a part of the base metal and constitutes an actual abrasive grain layer forming surface) is formed to enhance the smoothness of the abrasive grain layer forming surface, and then the electrolytic layer is formed thereon. The plating layer 12 may be formed.

Next, an example of a method of manufacturing the above electrodeposition grindstone will be described. In this method, first, the abrasive grain layer forming surface 1 of the base metal 10
After masking the parts except 0A, the base metal 10 is set in the electrolytic plating tank, and the electrolytic plating layer 12 is deposited while dispersing the large-diameter superabrasive particles 18 on the abrasive particle layer forming surface 10A, The superabrasive grains 18 are temporarily fixed in a single layer. When a Ni—Co based alloy is used for the electrolytic plating layer 12, a predetermined amount of Co salt such as Co sulfamate, Co chloride, Co bromide, etc. may be added to an ordinary Ni plating solution.

After the temporary fixing of the large-diameter superabrasive grains 18 is completed, the base metal 10 is immersed in an electroless plating bath in which the small-diameter superabrasive grains 16 are uniformly dispersed, and the small-diameter superabrasive grains 16 are placed on the electrolytic plating layer 12. The electroless plating layer 14 is deposited while being uniformly dispersed, and the large-diameter superabrasive grains 18 are embedded to a predetermined depth. The Ni-P electroless plating bath usable here is a known Ni-P plating bath using sodium hypophosphite as a reducing agent, or a tungstate salt such as sodium tungstate, sodium molybdate, etc. Molybdate, rhenate such as ammonium rhenate, etc.
The thing which added one or more types is mentioned.

On the other hand, as the electroless plating layer 14, Ni-B is used.
When using a base alloy, a boron hydride compound such as NaBH _{4 is} used as a reducing agent in an ordinary Ni electroless plating bath,
It is possible to use a Ni-B system electroless plating bath to which dimethylamine borane or the like is added, or a bath to which the above W, Mo, Re salt or the like is added.

After the electroless plating layer 14 is formed, the grindstone is washed to remove the masking, and then 300 to 50.
Heat treatment is performed at 0 ° C. for about 30 to 240 minutes. Then, P or B in the electroless plating phase is deposited, and 400 to before the heating.
The electroless plating phase, which had a hardness of about 700 Hv, is 800
Hardens to about 1000 Hv. Furthermore, W, Mo,
When Re is added, the maximum electroless plating phase is 120
It hardens to about 0 Hv, the high temperature strength and high temperature hardness of the electroless plating layer 14 increase, and a high abrasive grain holding force can be obtained even in grinding with a large amount of heat generation.

On the other hand, when the electrolytic plating layer 12 is formed of a Ni-Co type alloy, its hardness is 525 Hv in the deposited state,
It is 300 to 400 Hv after the heat treatment (400 ° C. or less), which is higher in hardness than the conventional Ni plating phase is reduced to 200 Hv or less after the heat treatment, and the abrasive grain holding force can be improved also from this point.

According to the electrodeposition grindstone having the above structure, the individual large-diameter superabrasive grains 18 that contribute to the grinding of the work material are Ni-P.
It is supported by the electroless plating layer 14 which is made of a Ni-B alloy or a Ni-B alloy and has a high hardness, and the electroless plating layer 14 has uniformly dispersed small-diameter superabrasive grains 16 of less than 5 μm. Therefore, these small-diameter superabrasive grains 16 reduce the contact frequency between the electroless plating layer 14 and the work material to reduce the wear rate of the electroless plating layer 14, and the small-diameter superabrasive grains 16 reduce the electroless plating layer 14 The effect of improving the rigidity of is obtained.

Therefore, in this electrodeposition grindstone, the holding power of the large-diameter superabrasive grains 18 by the electroless plating layer 14 is remarkably high,
Moreover, since the electroless plating layer 14 is less likely to be worn and the decrease rate of the abrasive grain holding force over time is small, the large-diameter superabrasive grains 18 are less likely to be unnecessarily removed even when grinding a difficult-to-cut material. And good sharpness can be maintained.

Further, since the electrolytic plating layer 12 which is softer than the electroless plating layer 14 is formed between the electroless plating layer 14 and the abrasive grain layer forming surface 10A of the base metal 10, a hard electroless plating is performed. The effect of alleviating the thermal stress generated between the plating layer 14 and the base metal 10 is obtained, and the possibility of peeling of the abrasive grain layer or the like is small even when performing grinding with a large amount of heat generation.

[0032]

[Experimental Example] Next, the effect of the present invention will be demonstrated with reference to an experimental example. (Experimental Example 1) A portion of the 1A1 straight type base metal having an outer diameter of 150 mm x an inner diameter of 50.8 mm x a thickness of 7 mm except for the surface where the abrasive grain layer is formed is masked, and the base metal is immersed in an electrolytic plating bath having the following composition. Then, a Ni undercoat layer having a thickness of 2 μm was formed on the surface of the abrasive grain layer.

Next, in an electrolytic plating bath having the following composition, a Ni--Co alloy layer was deposited on the undercoating layer to a thickness of 10 μm, and large-diameter diamond abrasive grains were temporarily fixed in a single layer. Co content of the obtained Ni-Co alloy phase is 30%
Became.

Electroplating Conditions Bath Composition Ni: Sulfamic Acid: 450 g / l Boric Acid: 30 g / l Ni Chloride: 10 g / l Brightening Agent: Small Amount Sulfamic Acid Co: 8 g / l Diamond Abrasive Grains: 10 g / l Abrasive Grain Average Particle Size : # 80/100 = 150 to 180
μm pH: 4 Bath temperature: 50 ° C. Current density: 0.03 A / cm ²

Next, the base metal is immersed in an electroless plating solution containing small-diameter superabrasive grains of the following composition and electroless plated at 85 ° C. to form small-diameter superabrasive grains on the Ni—Co alloy layer. A uniformly dispersed Ni-WP alloy layer was formed, and the temporarily fixed large-diameter superabrasive grains were embedded to 70% of the average grain size.
The composition of this Ni-WP alloy layer is Ni-9.24 wt%.
W-3.52 wt% P, the content of small-diameter superabrasive grains is 2
It became 0 vol%. In addition, clean the grindstone and
Heat treatment was performed at 50 ° C. for 100 minutes to obtain an electrodeposition grindstone. The hardness of the Ni-WP alloy phase is 1200 Hv due to the heat treatment.
Became.

Composition of electroless plating bath Nickel sulfate: 7 g / l Sodium tungstate: 35 g / l Sodium citrate: 40 g / l Sodium hypophosphite: 10 g / l Temperature: 95 ° C. pH: 9.8 Small diameter superabrasive Grain dispersion amount: 10 g / l Average diameter of small-diameter superabrasive grains: # 4000 = 2 to 4 μm

(Experimental Example 2) On the other hand, up to the electrolytic plating layer, the base metal formed under exactly the same conditions as in Experimental Example 1 was immersed in an electroless plating solution containing small-diameter superabrasive grains (SB-55 manufactured by Kanigen Japan Ltd.). Then, electroless plating is performed at 60 ° C. to uniformly disperse the above-mentioned small-diameter superabrasive grains on the Ni—Co alloy layer.
An alloy layer is formed and the temporarily fixed superabrasive particles are treated with an average particle size of 7
Embedded up to 5%. The composition of this Ni-B alloy phase is 99.
wt% Ni-1 wt% B, and the content ratio of the small-diameter superabrasive grains was 10 vol%. Further, the grindstone was washed and heat-treated at 400 ° C. for 120 minutes to obtain an electrodeposition grindstone.
By the heat treatment, the hardness of the Ni-B alloy phase became 1000 Hv.

(Experimental example 3) Experimental example 1 up to the electrolytic plating layer
Immerse the base metal formed in the same manner as in 1.
Electroless plating at ℃, Ni-Co on the Ni-Co alloy layer
A B-Mo alloy layer was formed and the temporarily fixed superabrasive grains were embedded up to 65% of the average grain size. The composition of this electroless plating layer was Ni-23 wt% Mo-1 wt% B. Further, the grindstone was washed and heat-treated at 430 ° C. for 120 minutes to obtain an electrodeposition grindstone. The heat treatment brought the hardness of the electroless plating phase to 1100 Hv.

Comparative Example 1 An electrodeposition grindstone was obtained by performing eutectoid plating on the same base metal as described above using a Ni plating bath having the following composition. The amount of abrasive grains embedded is the same as above. Ni sulfamic acid: 450 g / l Boric acid: 30 g / l Ni chloride: 10 g / l Brightening agent: small amount Diamond abrasive grain amount: 10 g / l Diamond abrasive grain size: # 80/100

(Comparative Example 2) A grindstone described in JP-A-63-221977 was prepared. First, a Ni plating layer having a thickness of 4 μm was formed on the ground surface of the same base metal as described above by using an electrodeposition plating method. Next, the abrasive grains were electrodeposited using a Ni plating solution in which # 80/100 diamond abrasive grains were suspended to form a Ni plating layer having an average thickness of 10 μm. Furthermore, 70% of the average particle size is obtained by electroless plating on this.
A Ni-P alloy plating layer was formed until the embedded. The electrodeposition grindstone manufactured in this way is heated to 400 ° C.
The hardness of the P alloy plating phase was increased to about Hv800.

(Comparison method) The following grinding tests were carried out using the five kinds of grindstones prepared as described above, and the grinding performances were compared. Table 1 shows the abrasive grain residual ratio (%) and the finished surface roughness: Rmax (μm) at the time of grinding the work material by 15 cc. Grinding conditions Wheel peripheral speed: 1500 m / min Table feed: 10 m / min Cross feed: 2 mm / Pass Depth of cut: 0.015 mm Work material: cemented carbide (Mitsubishi Material Co., Ltd. product name "Diatitanit") Grinding fluid: Chemical solution: 50 times dilution

[0042]

[Table 1]

As is clear from the above table, it was confirmed that the grindstones of Experimental Examples 1 to 3 had a higher rate of residual abrasive grains than the grindstones of Comparative Examples 1 and 2, and had extremely high abrasive grain holding power. It was also confirmed that chipping did not easily occur during grinding of hard and brittle materials such as cemented carbide, and the finished surface roughness was good.

[0044]

As described above, according to the electrodeposition grindstone of the present invention, the individual large-diameter superabrasive grains that contribute to the grinding of the work material are made of Ni-P type alloy or Ni-B type alloy. It is supported by the electroless plating layer having extremely high hardness, and since the small diameter hard particles of less than 5 μm are uniformly dispersed in the electroless plating layer, the small diameter hard particles form an electroless plating layer. The effect of reducing the contact frequency with the work material to reduce the wear rate of the electroless plating layer, and the effect of improving the rigidity of the electroless plating layer by the small diameter hard particles can be obtained.

Therefore, in this electrodeposition grindstone, the holding force of the large-diameter superabrasive grains by the electroless plating layer is remarkably high, and the electroless plating layer is less likely to be worn and the reduction rate of the holding force of the abrasive grains is small. Even when the material is ground, the large-diameter superabrasive particles are less likely to be uselessly dropped off, and good sharpness can be maintained for a long period of time.

Further, since the electrolytic plating layer which is softer than the electroless plating layer is formed between the electroless plating layer and the abrasive grain layer forming surface of the base metal, the hard electroless plating layer and the base metal are The effect of alleviating the thermal stress generated during the process is obtained, and the excellent effect that there is little risk of peeling of the abrasive grain layer even when performing grinding with a large amount of heat generation is achieved.

[Brief description of drawings]

FIG. 1 is an enlarged sectional view showing an embodiment of an electrodeposition grindstone of the present invention.

FIG. 2 is an enlarged sectional view showing an example of a conventional electrodeposition grindstone.

[Explanation of symbols]

 10 Base metal 10A Abrasive grain layer forming surface 12 Electrolytic plating layer 14 Electroless plating layer 16 Small diameter super abrasive grain (small diameter hard particle) 18 Large diameter super abrasive grain

Claims (4)

[Claims] 1. An electrolytic plating layer and an electroless plating layer are sequentially formed on a surface of a base metal on which an abrasive grain layer is formed, and an average particle diameter of 50 μ is embedded in the electrolytic plating layer and the electroless plating layer.
A large number of large-diameter superabrasive grains of m or more are fixed in a single layer along the surface of the abrasive grain layer, and the electroless plating layer contains P in an amount of 1 to 20 wt% and is a heat-hardened Ni alloy. In addition, super-abrasive grains and S are contained in the electroless plating layer.
One or two selected from iC, Si ₃ N ₄ and Al ₂ O ₃
5 to 35 hard and small particles having an average particle diameter of 5 μm or less
vol% An electrodeposited whetstone that is evenly dispersed. 2. An electrolytic plating layer and an electroless plating layer are sequentially formed on an abrasive grain layer forming surface of a base metal, and an average particle diameter of 50 μ is embedded in the electrolytic plating layer and the electroless plating layer.
A large number of large-diameter superabrasive grains of m or more are fixed in a single layer along the surface of the abrasive grain layer formation, and the electroless plating layer contains 0.2 to 15 wt% of B and is heat-cured Ni. In the electroless plated layer, one or more selected from super-abrasive grains, SiC, Si ₃ N ₄ , and Al ₂ O ₃ are hard and small particles having an average particle size of 5 μm or less. 5
An electrodeposition grindstone characterized by being uniformly dispersed up to 35 vol%. 3. The Ni alloy forming the electroless plating layer further contains 0.5 to 30 wt% of one or more elements selected from W, Mo and Re. The electrodeposition grindstone described. 4. The thickness of the electroless plating layer is 0.1 to 0.7 times the average grain size of the large-diameter superabrasive grains, and the total thickness of the electroplating layer and the electroless plating layer. The diameter is 0.2 to 0.8 times the average particle size of the large-diameter superabrasive particles, and the electrodeposition grindstone according to claim 1, 2, or 3.