JPH04322972A - Binder material for diamond abrasive grain - Google Patents

Abstract

PURPOSE:To provide a novel binder material which is made possible for truing and dressing a diamond abrasive grain and its bonding layer so efficiently in a highly accurate manner by means of a diamond dresser. CONSTITUTION:A filler and a pore-forming material are mixed in vitreous power, and a diamond abrasive grain is mixed in addition to that and then they are baked at a temperature through which the vitreous powder is melted. Vitreous binders 2 are concentrated on each surface and contact parts of abrasive grains by means of surface tension, and thereby a lot of bubbles 3 are formed in space between the binder and the abrasive grain. When compressive force is added to the surface of a bonding layer by a dresser, the vitreous binder 2 is crushed and truing takes place, and the abrasive grain 1 is projected out of the binder 2 by means of the bubble 3, turning to a sharp edge.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a binder material for diamond abrasive grains.

0002

[Prior Art and its Problems] In the bonding layer of resin bond or metal bond conventionally used for bonding diamond abrasive grains, as shown in FIG. The structure is such that there are no pores inside the bonding layer. For this reason, when the surface of the grindstone is trued as shown by the broken line y, the abrasive grains 1' and the binder 2' become flush with each other and no cutting edge is formed, resulting in a state in which dressing is not possible at all. Therefore, it was necessary to perform dressing again after truing to make the abrasive grains protrude from the binder.

[0003] Furthermore, when a diamond abrasive wheel with bonded diamond abrasive grains is trued or dressed with a diamond dresser, the wear of the dresser is large because the cutting edges are made of materials with the same hardness, and the contact area between the two is truing or dressing. There is a problem in that severe rubbing occurs and the actual amount of cut that can be obtained is extremely small.

FIG. 3(a) shows the amount of machining relative to the cutting rate when a diamond grinding wheel using a resin bond is dressed with a diamond rotary dresser, and the wear amount of the dresser is determined by the amount of dressing of the grinding wheel. are occurring in the same amount. Moreover, about 90% of the total cutting depth is uncut due to elastic deformation, and the amount of dressing actually obtained is extremely small.

[0005] In this way, conventional diamond grinding wheels have
It is difficult to form a highly accurate grindstone surface by truing, and in order to obtain the required surface roughness and other surface quality of the workpiece, it is necessary to adjust the grain size of the diamond grindstone. That is, in order to obtain good surface quality, it is necessary to use diamond abrasive grains with a fine particle size.

[0006] However, such a reduction in the diameter of the abrasive grains inevitably leads to a reduction in machining efficiency and a shortening of the life of the grinding wheel, which is a factor that makes it difficult to apply diamond grinding wheels to mass production processing by grinding.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a bonding agent material for diamond abrasive grains that allows diamond abrasive grains and their bonding layer to be trued and dressed with high efficiency using a diamond dresser.

[0008]

[Means for Solving the Problems] In order to solve the above problems, the binder material of the present invention includes a filler consisting of glass or silicate mineral powder, silicon carbide or aluminum oxide powder, and a thermal sublimation material. It consists of a mixture with a pore-forming material made of powdered material, and the weight ratio of the filler to the total weight is 7 to 85.
%, and the weight percentage of the pore-forming material is set in the range of 0 to 40%.

In the above structure, it is preferable that the filler has a particle size of 10 to 100% of the diamond abrasive grains, and the particle size of the pore former is 20 to 400% of the particle size of the diamond abrasive grains.
It is desirable to set it in the range of μm.

0010

[Operation] Diamond abrasive grains are mixed into the binder material having the structure as described above, and the mixture is fired to a temperature at which the glass powder or silicate mineral powder melts and becomes vitrified. As a result, as shown in FIG. 1, the bonding agent 2 concentrates on the surfaces of the abrasive grains 1 and the contact portions of the abrasive grains due to its surface tension and becomes vitrified, thereby bonding the abrasive grains 1 together.

Furthermore, a large number of pores 3 are formed between the abrasive grains 1 and between the binder 2 due to the action of the filler and the pore-forming material.

[0012] In the above structure, the glassy binder 2 has hard and brittle properties, so when it receives compressive force due to contact with the diamond dresser, the binder 2 is destroyed, and the binders and the binder are and the abrasive grains are separated. Therefore, truing can be performed with high efficiency.

Furthermore, since the vitreous binder 2 has a high Young's modulus and does not undergo elastic deformation, there is almost no uncut portion as shown in FIG. 3(a), and highly accurate processing is possible.

Furthermore, since pores 3 exist between the binder 2 and the abrasive grains 1, when the grinding wheel surface is trued as shown by the broken line x in FIG. 1, the abrasive grains 1 protrude from the binder 2 and the rake face becomes A cutting edge is formed. That is, good dressing as well as truing becomes possible.

[0015]

【Example】

<Experiment 1> Four types of diamond whetstone test items (A, B
, C, and D) were manufactured, and the dressing performance using a diamond rotary dresser was compared with a conventionally used resin-bonded diamond grindstone.

[0016] The test products (A, B, C, D) were prepared by mixing glass powder and silicate mineral powder as binder raw materials with a thermal sublimation material as a pore-forming material in an amount of 0 to 40% of the binder raw material weight,
The formulation includes SiC (particle size #500) as a filler.
The powder was mixed in a weight ratio shown in Table 1 with respect to the weight of the binder raw material, and the mixture was mixed with diamond abrasive grains, and then fired at a temperature higher than the temperature at which the binder raw material melted.

[0017]

[Table 1]

Each test article (A to D) prepared had a diamond particle size of #400 and a diamond concentration of 100, and the mechanical properties of each test article are as shown in Table 1. On the other hand, the resin-bonded diamond grindstone used for comparison had a diamond grain size of #325 and a diamond concentration of 100.

On the other hand, the diamond rotary dresser uses a metal bond type and has a diamond particle size of #4.
0 and diamond concentration of 100 were used. The mechanical properties of the bonding layer of this dresser are shown in Table 1.

The comparison results are shown in FIG. As shown in this figure, while the conventional resin bonded diamond grinding wheel cannot be trued or dressed at all with a diamond rotary dresser, each test item (A, B, C, D)
showed an extremely high dressing rate, although there were slight differences depending on the composition.

<Experiment 2> Fig. 4 shows the machining results when surface grinding of cemented carbide was performed using the above-mentioned test piece A that was trued with a diamond rotary dresser and a resin bonded diamond grindstone that was trued and dressed using the conventional method. .

As shown in the figure, although the test specimen A has a slightly higher grinding resistance than the resin-bonded diamond grindstone, it has a large grinding ratio and exhibits excellent grinding performance.
It can be seen that the dressing was done well.

[0023]

[Effects] As described above, the binder material of the present invention uses glass as the main raw material and forms a large number of pores inside the bonding layer when fired with abrasive grains. The bonding agent is easily destroyed and trued, and the presence of pores causes the abrasive grains to always protrude from the bonding agent and become dressed.

[0024] Therefore, truing and dressing can be performed with high efficiency using a diamond dresser, which has the effect of making it possible to apply the diamond grindstone to mass-produced grinding.

[Brief explanation of drawings]

[Figure 1] Diagram schematically showing the internal structure of a bonding layer

[Figure 2] Diagram showing the internal structure of a conventional bonding layer

[Figure 3] Comparison diagram of dressing rate due to different bonding layers

[Figure 4] Comparison diagram of grinding performance due to different bonding layers

[Explanation of symbols]

1 Abrasive grain 2 Binder 3. Pores

Claims (3)

[Claims] 1. Consisting of a mixture of glass or silicate mineral powder, a filler consisting of silicon carbide or aluminum oxide powder, and a pore-forming material consisting of a heat sublimation material powder, the amount of filler relative to the total weight The weight percentage is in the range of 7 to 85%,
A binder material for diamond abrasive grains in which the weight percentage of the pore-forming material is set in the range of 0 to 40%. [Claim 2] The filler is made of diamond abrasive grains of 10 to 10%.
The diamond abrasive binder material according to claim 1, having a particle size of 100%. 3. The binder material for diamond abrasive grains according to claim 1, wherein the particle size of the pore-forming material is set in a range of 20 to 400 μm.