JP2008155362A - Electrodeposited diamond tool and manufacturing method for the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrodeposited diamond tool that prevents abrasive grains from dropping out and achieves a long service life. <P>SOLUTION: In the electrodeposited diamond tool, a plurality of diamond particles 14 is firmly fixed on a surface of a base material 11 by an electrolytic nickel deposit film 15, and additionally an electroless nickel deposit film 16 is formed over the electrolytic nickel deposit film 15. The electroless nickel deposit film 16 is preferably set to have higher hardness than the electrolytic nickel deposit film 15 by heat treatment. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electrodeposited diamond tool which has been plated to prevent crushing and falling off of diamond particles and a method for manufacturing the same.

Electrodeposited diamond tools are used for precision machining of hard parts such as ceramics or cemented carbide. The electrodeposition diamond tool has a structure in which diamond fine particles are uniformly arranged and bonded with metallic nickel. Since electrodeposited diamond tools are expensive, in order to prevent diamond particles from falling off, no extra force is applied to the tools when machining parts.
Conventionally, as a method for manufacturing an electrodeposited diamond tool, a base material is electrodeposited with 5 to 6 μm of Watt bath nickel as a base plating, and then diamond abrasive grains are dispersed. Thereafter, a method is known in which the Watt bath nickel is again electrodeposited so that the embedding rate is 70% (Non-patent Document 1). As for the holding force of the nickel film on the abrasive grains, dropping occurs when the filling rate is 30%, and dropping occurs when the filling rate is 50%. In order to prevent the dropout, it is necessary to increase the embedding rate to 70% (Non-Patent Document 2).
Effect of abrasive grain distribution density on fabrication and grinding performance of stainless steel substrate electrodeposited diamond wheel Kinji Sato et al .: Surface Technology, Vol. 45, p92 (1994) Holding power against single grain of nickel film in electrodeposited diamond grinding stone Kinji Sato et al .: Surface Technology, Vol.46, p87 (1995) However, even if it is processed with great care, it is a relatively early stage of processing Therefore, phenomena such as diamond particle falling off or diamond particle breaking off are likely to occur. This phenomenon is an important issue for the development of new technologies because it causes the productivity of grinding processes to be hindered.

Usually, if the embedding rate is increased in order to prevent the diamond particles from falling off the electrodeposited diamond tool, there is a drawback that the height of the exposed diamond abrasive grains is reduced and the grinding ability is lowered. In addition, there is a disadvantage that diamond abrasive grains are crushed and dropped in the process of grinding using a diamond tool. When diamond abrasive grains are crushed and dropped, the grinding life of a tool that should be originally possessed is shortened. Generally, in order to prevent crushing and dropping of abrasive grains, measures such as reducing the pressing force during grinding or reducing the cutting amount are taken, but this reduces the productivity of the grinding operation.
Thus, in the conventional tool, dropping off of the abrasive grains reduces the productivity of the grinding operation. An object of the present invention is to provide an electrodeposited diamond tool that prevents falling off of abrasive grains and has a long life, and a method for manufacturing the same.

In order to achieve the above object, the electrodeposited diamond tool according to the present invention has a large number of diamond particles fixed to the surface of a base material by an electrolytic nickel film, and further an electroless nickel film is formed covering the electrolytic nickel film. It is characterized by.
Also, the hardness of the electroless nickel coating is adjusted to be higher than the hardness of the electrolytic nickel coating by heat treatment.

In addition, the electroless nickel plating film is projected on the surface of the diamond particle at the boundary with the diamond particle.
It is preferable that the thickness ratio of the electrolytic nickel plating film to the electroless nickel plating film is 9: 1.
Instead of the electrolytic nickel plating film, an electrolytic copper plating film may be formed.

  In addition, the method for producing an electrodeposited diamond tool according to the present invention includes a step of subjecting a base material to surface treatment, and electrolytic nickel plating using an electrolytic nickel plating solution in which diamond particles are mixed on the surface-treated base material. Applying the diamond particles temporarily, applying the electrolytic nickel plating on the electrolytic nickel plating film on which the diamond particles are temporarily fixed, and fixing the diamond particles on the substrate, and then the electrolytic nickel plating film And a step of forming an electroless nickel plating film thereon.

It is preferable to heat-treat the tool on which the electroless nickel plating film is formed so that the hardness of the electroless nickel film is higher than the hardness of the electrolytic nickel film.
In the electroless nickel plating step, the electroless nickel plating film may be plated so as to rise on the diamond particle surface at the boundary with the diamond particles.
The plating may be performed so that the thickness ratio of the electrolytic nickel plating film to the electroless nickel plating film is 9: 1.

  According to the present invention, diamond fine particles are strongly bonded to a substrate with an electrolytic nickel plating film and an electroless nickel plating film, preventing the diamond abrasive grains from falling off, and having a long life and high grinding. We can provide electrodeposition diamond tools with performance.

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
FIG. 1 is an explanatory view of the structure of an electrodeposited diamond tool 10 in which a nickel plating film is formed so as to enclose diamond abrasive grains. The structure will be described below together with the production method.
11 is a base material, and SS400 material was used in this Embodiment. A base nickel plating film 12 is formed on the surface of the substrate 11 by electrolytic plating.

Furthermore, electrolytic nickel plating is performed on the underlying nickel plating film 12 using an electrolytic nickel plating solution mixed with diamond particles 14 to temporarily attach the diamond particles 14.
The diamond particles 14 are mixed in a large amount in the nickel plating solution (for example, 160 g of diamond abrasive grains are mixed in 40 mL of the plating solution), and the tool is immersed in the nickel plating solution in a slurry state, while rotating the tool. Perform electrolytic nickel plating. By rotating the tool, the diamond particles 14 collide with the tool surface, adhere to the tool surface by the deposited nickel plating film 13, and are temporarily attached.

  Next, electrolytic nickel plating is further performed on the electrolytic nickel plating film 13 on which the diamond particles 14 are temporarily attached, and the diamond particles 14 are fixed on the substrate 11 by the electrolytic nickel plating film 15 to be deposited. These electrolytic nickel plating films 12, 13, and 15 are preferably filled with diamond particles 14 by about 60%.

Next, electroless nickel plating is performed on the electrolytic nickel plating film 15 to form an electroless nickel plating film 16. About 70% of the diamond particles 14 may be filled with the electrolytic nickel plating films 12, 13, 15 and the electroless nickel plating film 16.
By thickening the electroless nickel plating film 16, the electroless nickel plating film 16 can be raised in a nail shape on the surface of the diamond particles 14 at the boundary with the diamond particles 14. The raised portion 17 firmly fixes the diamond particles 14, can prevent the drop off as much as possible, can extend the life, and can improve the grinding performance accordingly.

Although the electrodeposited diamond tool 10 is obtained as described above, it is more preferable to heat-treat the electrodeposited diamond tool 10 in a vacuum.
By this heat treatment, the electrolytic nickel plating films 12, 13, and 15 have relatively low hardness and softness. On the other hand, the electroless nickel plating film 16 has a high hardness. Thereby, during grinding, a strong impact from an object to be ground is received by the soft electrolytic nickel plating films 12, 13 and 15, so that the diamond particles 14 are prevented from being crushed, while the electroless nickel film 16 having a high hardness prevents the diamond particles from being broken. Since 14 is firmly held, the diamond particles 14 are prevented from falling off.

  Specifically, as shown in Table 2 to be described later, in the two-layer plating sample, the hardness of the upper electroless nickel plating film 16 was HV445 after plating, but became hard to HV682 by heat treatment. It has become. In the lower layer, the hardness of the electrolytic nickel plating film 15 that has been HV477 after plating is lowered to HV444 by heat treatment. This provides a flexible film structure that can handle the load load during grinding, which is considered to contribute to the improvement of grinding performance.

The ratio of the thicknesses of the electrolytic nickel plating films 12, 13, 15 and the electroless nickel plating film 16 is preferably 8.5: 1.5 to 9.5: 0.5, and optimally 9: 1. Met. This is because if the hard electroless nickel plating film 16 is too thick, the whole becomes brittle. If it is too thin, the strength decreases and the diamond particles 14 fall off.
In addition, it replaced with the electrolytic nickel plating film | membrane 12,13,15, and the same effect (crushing of diamond particle | grains 14 and prevention of omission) was acquired even if it formed the electrolytic copper plating film | membrane which is a soft metal.

  Examples of the present invention will be described in detail below, but the scope of the present invention is not limited to these examples.

Example 1
1) SS400 material was used as the base material 11. The surface of the substrate 11 was polished with # 800 water-resistant polishing paper, and then degreased and pickled with hydrochloric acid. First, base nickel plating was performed to form a base nickel plating film 12.
As a plating bath
Nickel sulfamate 600g / L
Boric acid 40g / L
Pit inhibitor 4mL / L
Was used under the conditions of a current density of 3 A / dm ² and an electrolysis time of 10 minutes.

2) As the diamond abrasive grains, a particle diameter of 150 to 200 μm manufactured by Tomei Diamond Industrial Co., Ltd. was used. With the diamond particles suspended in the plating bath in a slurry state, an electric current was applied to form a temporary nickel plating film 13 to perform temporary plating of the diamond particles. As a plating bath, nickel sulfamate 600g / L
Boric acid 40g / L
Pit preventive agent 3mL / L
, And a current density of 5 A / dm ² and an electrolysis time of 10 minutes.
In addition, 160 g of diamond abrasive grains were mixed in 40 mL of the plating solution, and electrolytic plating was performed while rotating the tool using a slurry-like plating solution that was concentrated and dispersed.

3) Next, main plating was performed so that the embedding rate was 50%, and an electrolytic nickel plating film 15 was formed. As a plating bath, nickel sulfamate 600g / L
Boric acid 40g / L
Pit preventive agent 3mL / L
Brightener NSF-E 10mL / L
Was used under the conditions of a current density of 3 A / dm ² and an electrolysis time of 70 minutes.

4) In electrolytic nickel plating, since hydrogen gas is generated during electrolysis, pits are generated in the plating film. In order to obtain a high-quality plating film, selection of a pit inhibitor is important. In this example, pitless S (manufactured by Nippon Chemical Industry Co., Ltd.) was used as a pit inhibitor.
Moreover, in this plating, unevenness becomes severe as the plating film grows. In order to obtain a flat plating film, selection of a brightener is important. In this example, NSF-E (manufactured by Nippon Chemical Industry Co., Ltd.) was used as a brightener.

5) Next, electroless nickel plating was performed on the electrolytic nickel plating film 15 to form an electroless nickel plating film 16. Once the electrolytic nickel plating is lifted from the plating bath, it is covered with an inactive film, and even if plating is applied again to this film, the adhesion between the films is weak and the film is peeled off immediately. Then, after immersing in the following selective activation liquid and performing the selective activation process, electroless nickel plating was performed.
Selective activation solution 15% hydrochloric acid 1L
Sodium lauryl sulfate 0.25g / L
Temperature Room temperature Time 5 minutes

6) Immediately after the activation treatment, electroless nickel plating was performed under the following conditions.
Econic NSX (manufactured by Uemura Kogyo Co., Ltd.)
Temperature 85 ° C
Time 1 hour FIG. 2 shows an SEM image of the electroless nickel plating film deposited on the edge of the diamond abrasive. By thickening the electroless nickel plating film 16, the electroless nickel plating film 16 can be raised in a nail shape on the surface of the diamond particles 14 at the boundary with the diamond particles 14. The raised portion 17 (the white dot-like portion in FIG. 2A) wraps the diamond abrasive grains in the form of a nail that fixes the diamond jewel to the base of the ring. The deposition state of electroless nickel plating is shown in FIG. Compared to the conventionally known diamond electrodeposition tool, the structure is such that the abrasive grains are less likely to fall off, and the grinding performance as a tool is improved.

Example 2
For the purpose of depositing the electroless nickel plating film 16 quickly and firmly on the electrolytic nickel plating film 15, a strike nickel plating process was incorporated. Nickel chloride 240g / L as strike nickel plating bath
Hydrochloric acid 125mL / L
The surface of the base electrolytic nickel plating film 15 was activated under the conditions of a current density of 8 A / dm ² and an electrolysis time of 1 minute. Next, electroless nickel plating was performed under the following conditions.
Econic NSX (manufactured by Uemura Kogyo Co., Ltd.)
Temperature 85 ° C
1 hour

  In the strike nickel plating process, it is considered that the surface of the underlying electrolytic nickel plating film 15 is activated, but at the same time, the diamond abrasive grains are also activated. That is, the deposition reaction of strike nickel plating is accompanied by the generation of hydrogen gas, and it is considered that the hydrogen in this generation stage destroys and removes the organic film existing on the diamond abrasive grain surface. Due to the effect of activating the surface of the diamond abrasive grains, as shown in FIG. 2B, the rising portion 17 of the electroless nickel plating film 16 is deposited on the entire periphery of the diamond abrasive grains.

Example 3
In an electrodeposited diamond tool, electrodeposition strain remains in the electrodeposited nickel film. Heat treatment was performed for the purpose of improving the grinding performance of the electrodeposited diamond tool. The heat treatment was performed in vacuum at 100 ° C., 200 ° C., 300 ° C., and 400 ° C. for 1 hour. The heat-treated sample was tested for grinding performance.
The grinding performance of the electrodeposited diamond tool was investigated using a scratch tester MMS-2491 manufactured by Nissho Electric Co., Ltd. An alumina ceramic piece (3x4x12mm, 1000Hv) was horizontally reciprocated as a material to be ground using each prototype tool under a load of 30N, 5mm reciprocating, and dry conditions. Grinding performance was evaluated by measuring vertical displacement and grinding resistance. The results are shown in FIG. In FIG. 3, the code | symbol 31 shows the grinding performance of the tool obtained in Example 2, and the code | symbol 32 shows the tool heat-processed in Example 3 at 100 degreeC. The horizontal axis represents time (min).

  The sample heat-treated at 100 ° C. has improved grinding performance by about 18% compared to the sample as plated. It is considered that the grinding performance was improved by removing the electrodeposition distortion. On the other hand, in the samples heat-treated at 200 ° C., 300 ° C., and 400 ° C., the grinding performance decreased. As shown in Table 1, this is probably because the electrolytic nickel film 15 was softened by the heat treatment, and thus the rolling force during grinding could not be supported. In addition, although the grinding performance is lower than that of the untreated in the heat treatment at 200 ° C. or higher, this is an example when the electrolytic nickel plating having the bath composition shown in this example is used, and the nickel plating bath having a different bath composition. Obviously, there is a different optimum heat treatment temperature when using.

  Using a tool produced by electrolytic nickel plating, the effect of heat treatment temperature and treatment time on the hardness of the coating was investigated. The results are shown in Table 1.

    The grinding performance of the heat-treated tool was also tested. The results are shown in FIG. In FIG. 4, reference numeral 41 denotes a tool obtained in Example 1, reference numeral 42 denotes a tool heat-treated at 100 ° C. for 1 hour in Example 3, and reference numeral 43 denotes a tool heat-treated at 100 ° C. in Example 3 for 10 hours. The grinding performance improved by about 13% after the heat treatment for 1 hour. Thereafter, heat treatment was performed for up to 10 hours, but the grinding performance was almost the same as that of the one-hour treatment.

    Next, the tool shown in Example 3 was heat-treated at 100 ° C. for 1 hour in a vacuum, and then the hardness of the coating was tested. The results are shown in Table 2.

  Next, an experiment was conducted on the effect of the ratio of the thickness of the underlying electrolytic nickel plating film 15 and the thickness of the upper electroless nickel plating film 16 on the performance of the electrodeposited diamond tool. Sample 1 in which the thickness of the upper electroless nickel plating film 16 is 1 with respect to the thickness 9 of the lower electrolytic nickel plating film 15, and the upper layer with respect to the thickness 9 of the lower electrolytic nickel plating film 15 An experiment was conducted on Sample 2 in which the thickness of the electroless nickel plating film 16 was 4.5. The sample used in Example 3 was heat-treated at 100 ° C. for 1 hour in an argon atmosphere. FIG. 4 shows the results of the grinding performance test. In FIG. 4, reference numeral 51 indicates the sample 1 and reference numeral 52 indicates the sample 2. The upper electroless nickel plating film 16 becomes hard by heat treatment and becomes HV682. The diamond abrasive grains are firmly held by the hard electroless nickel plating film 16 and are difficult to fall off during grinding. However, when the hard electroless nickel plating film 16 is thick, that is, when the underlying soft electrolytic nickel plating film 15 is thin, the diamond abrasive grains are crushed without being able to withstand the load applied during grinding. From these results, a tool obtained by heat-treating a tool having an electrolytic nickel plating film: 90 μm and an electroless nickel plating film: 10 μm at 100 ° C. for 1 hour showed the most excellent performance.

It is a schematic diagram of the structure which gave electroless nickel plating so that a diamond abrasive grain might be wrapped. (a) SEM image of electroless nickel plating film deposited on the edge of diamond abrasive grains. (b) SEM image of electroless nickel plating film deposited on the entire edge of diamond abrasive grains. It is a figure which shows the grinding performance of the tool heat-processed after 2 layer plating. It is a figure which shows the grinding performance of the heat-treated electrodeposition tool. It is a figure which shows the influence which the ratio of plating thickness has on grinding performance.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Base material 12 Base nickel plating film 13 Temporary nickel plating film 14 Diamond abrasive grain 15 Electrolytic nickel plating film 16 Electroless nickel plating film 17 Raised part

Claims (9)

  An electrodeposited diamond tool characterized in that a large number of diamond particles are fixed to the surface of a base material by an electrolytic nickel coating, and an electroless nickel coating is formed covering the electrolytic nickel coating.   2. The electrodeposited diamond tool according to claim 1, wherein the electrodeposited diamond tool is adjusted by heat treatment so that the hardness of the electroless nickel coating is higher than the hardness of the electrolytic nickel coating.   The electrodeposited diamond tool according to claim 1 or 2, wherein the electroless nickel plating film rises on the surface of the diamond particle at the boundary with the diamond particle.   The electrodeposition diamond tool according to any one of claims 1 to 3, wherein the ratio of the thickness of the electrolytic nickel plating film to the electroless nickel plating film is 9: 1.   The electrodeposited diamond tool according to any one of claims 1 to 4, wherein an electrolytic copper plating film is formed in place of the electrolytic nickel plating film. Applying a surface treatment to the substrate;
A step of temporarily attaching diamond particles by performing electrolytic nickel plating using an electrolytic nickel plating solution mixed with diamond particles on a surface-treated substrate;
Applying electrolytic nickel plating on the electrolytic nickel plating film on which the diamond particles are temporarily attached, and fixing the diamond particles on the substrate;
Then, the process of forming an electroless nickel plating film | membrane on the said electrolytic nickel plating film | membrane, The manufacturing method of the electrodeposition diamond tool characterized by the above-mentioned.   The electrodeposited diamond according to claim 6, wherein the tool on which the electroless nickel plating film is formed is heat-treated so that the hardness of the electroless nickel film is higher than the hardness of the electrolytic nickel film. Tool manufacturing method.   The electrodeposited diamond tool according to claim 6 or 7, wherein in the electroless nickel plating step, the electroless nickel plating film is plated so as to rise on the surface of the diamond particles at the boundary with the diamond particles. Manufacturing method.   The method for producing an electrodeposited diamond tool according to any one of claims 6 to 8, wherein plating is performed so that a thickness of the electrolytic nickel plating film and the electroless nickel plating film is 9: 1.