JPH0639730A - Hardened abrasive and manufacture thereof - Google Patents

Abstract

PURPOSE:To provide the nature of a grinding grain sinteried type grinding wheel and to make toughened abrasives suitable for machining of ceramics by a method wherein, after a molded product in which inorganic fibers selected from ceramics rigid and brittle materials are primarily cured by using thermosetting resin, such as epoxy resin is machined, the molded product is heated again to effect secondary curing. CONSTITUTION:A tank where thermosetting resin 3, such as epoxy resin, is contained is impregnated with 5-50vol.% inorganic fibers 2 of rigid and brittle materials, such as alumna fibers with a fibre size of approximate 15 micron, to effect primary heat curing treatment. The molded product is machined and further treated in a hot blast circulating furnace for one hour at, for example, 250 deg.C, for five hours at 300 deg.C, and for five hours at 350 deg.C to apply secondary curing treatment to produce a hardened abrasive 1 on which additional improvement is applied.

Description

Detailed Description of the Invention

[0001]

[Industrial application] Metals (iron / iron alloys, aluminum / alloys, copper and their alloys) and non-metals (stones, silicon, ceramics), especially as rough finish abrasives, and above Used as a finish abrasive for high hardness materials.

[0002]

2. Description of the Related Art In a conventional abrasive grain sintering type grindstone, a grindstone having a roughness or hardness of # 400 or # 600 can be relatively arbitrarily selected. Since it is a porous material and the content of abrasive grains is insufficient, it has the disadvantages of inefficiency, clogging of cutting chips, and easy breakage. On the other hand, the new grindstone made of inorganic fiber reinforced resin, which has recently been put into practical use, has the characteristics of long life, good sharpness and smooth and beautiful polished surface, but for roughing and hard surface processing. If it is not suitable, and it is expressed in the count specification of the abrasive grain sintering type grindstone #
It can only be used in a very limited range of numbers between 800 and # 1000.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to perform grinding of metal such as iron or ceramics which has the characteristics of an inorganic fiber reinforced resin and also has the characteristics of an abrasive grain sintering type grindstone. To provide abrasives.

[0004]

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present inventors have conducted development research with an emphasis on improvement from an inorganic fiber reinforced resin. As a result, it was found that the grinding ability was improved by secondarily hardening the unreacted components, and further performance improvement could be obtained by including coarse abrasive grains in the hardening agent in advance.

Regarding the improved product by the secondary curing treatment and the manufacturing method thereof: the inorganic fiber has a thickness of 3 to 30 μm, and regarding the fiber aggregate state, roving, woven fabric or non-woven fabric is prepared and the content of the fiber is prepared. Of the curing agent in advance so as to be 45 to 85% by weight, and a known method, for example, a drawing method in a heating die shown in Japanese Patent Application No. 63-047374 or pressurization / heating in the die. A cured original plate is obtained by the curing method. This is preliminarily cut into practical dimensions and used as a grinding and polishing material.

Then, the secondary hardening reaction H _{1 for} hardening in the hot air circulating oven is controlled according to a program adjusted within the condition of exposing the hot air in the hot air oven at 250 to 350 ° C. for 1 to 5 hours. Perform H ₂ and H ₃ . Finally, the air blow for heating is stopped, the furnace is left in the OFF state and gradually cooled to obtain the desired hardened abrasive material 1.

Regarding the additional improved product containing abrasive grains and subjected to the secondary hardening treatment and its manufacturing method: the thickness of the inorganic fiber is 3
The curing agent is pre-measured so that the weight of the fiber aggregate, which is roving, woven fabric, or non-woven fabric, is 45 to 85 wt%, and the resin used for this curing agent is epoxy resin or A saturated polyester resin, a vinyl ester resin, a bismaleimide resin, a phenol resin or the like; 5 to 50 (preferably 10) abrasive grains such as carborundum, alumina, silicon nitride or diamond are added to the resin stock solution of this curing agent. 30 to 30% by volume uniformly mixed; a cured original plate is obtained by a molding method or a pressure / heat curing method in a mold. This is preliminarily cut into practical dimensions and used as a grinding and polishing material.

Then, a secondary hardening reaction H _{1 for} hardening in the hot air circulating oven is controlled according to a program adjusted within the range of 1 to 5 hours of exposure in the hot air oven at 250 to 350 ° C. Perform H ₂ and H ₃ . Finally, the heating blast is stopped and the cooling is turned off by leaving it in the furnace to obtain the target hardened abrasive material 1.

[0009]

Functions known in the prior art, for example, Japanese Patent Application No. 63-04
In the grinding / abrasive material hardened / molded / processed by the drawing method in the heating die shown in 7374 or the pressure / heat hardening method in the die, the bonded portion (hardened resin portion 3) Is not strong enough and the structure is soft. The reason is that the unreacted component 4 remains in the resin portion only when it is cured by the conventional known method.
Because of this, in the cutting element pointed blade 6 at the fiber end, which is originally supposed to be firmly held, its support is loosened and the grinding energy is consumed there, degrading the grinding ability.
Is assumed. Therefore, if the unreacted residue 4 in the flexible resin portion is secondarily reacted to complete the curing and form a strong matrix, the above-mentioned drawbacks are eliminated. If the secondary curing conditions are adjusted to a low temperature for a short time and the central part is left unreacted, a product with structural characteristics that the outer peripheral part is hard and the inner part is soft across the hard / soft conversion zone 5 What can be obtained can be easily inferred. The above is the reason why the grinding and polishing material according to the present invention is more suitable for polishing a super hard material.

Further, since the matrix structure is strong, it is possible to cancel the deterioration of the structure caused by newly interposing abrasive grains in the resin portion 3. Therefore, it can be said that, for example, even if # 400 abrasive grains are mixed in the resin portion 3 and mixed, the original characteristics of the inorganic fiber reinforced resin grindstone, that is, toughness, long life and high efficiency will not be impaired. This is the reason why the grinding / abrasive material becomes more suitable especially for rough cutting.

[0011]

[Examples] Adjustment of grinding and polishing material: 100 parts of epoxy resin (AER331 manufactured by Asahi Kasei Co., Ltd.), 75 parts of methylhymic acid anhydride (MHAC manufactured by Hitachi Chemical Co., Ltd.), 2 ethyl 4-methylimidazole (2E4MZ-C manufactured by Shikoku Chemicals Co., Ltd.)
N) Denka alumina fiber having a fiber diameter of 15 microns (manufactured by Denka Industry Co., Ltd.) in a tank containing a resin composition consisting of 1 part
After impregnating the tree with the resin, squeeze and adjust the resin liquid so that the fiber content is approximately 60% by weight with respect to the tree portion,
125 ° C. A dense original plate is obtained by reacting under the conditions of 60 kg / m ² · 2 hours. This is cut and processed with a diamond cutter to a thickness of 2 mm, a width of 10 mm and a length of 100 mm to obtain a grinding and polishing material. Further, this is subjected to the next secondary hardening treatment step or, as a comparative example, directly subjected to a grinding and polishing test.

Secondary curing treatment: According to the temperature-time program shown in FIG. 3, H ₁ 250 ° C. for 1 hour, H ₂ 3
0.5 hours at 00 ℃, 0.5 hours at H ₃ 350 ℃, stay in the hot air circulation furnace, and leave it in the furnace for 1 hour after shutting off the hot air.
Then, after taking it out to a room temperature and bringing it to room temperature, this hardened abrasive material is subjected to the next abrasiveness test.

Mixing of abrasive particles: 10% by weight of diamond abrasive particles (Showa Denko Co., Ltd., # 400 abrasive particles) was uniformly mixed with the resin liquid used in the preparation of the grinding / polishing material described above. According to the same method as above for adjusting the grinding and polishing material,
After obtaining a grinding and polishing material, it is connected to the above-mentioned secondary curing process.

Grinding and polishing test material: S45C steel plate 50 mm long, 50 mm wide, 5 mm thick

Grinding and Polishing Test Conditions Vibration Shaft: Vibration Rotating Tool (SF-500 manufactured by Sonotec Co., Ltd.
0) Use frequency: 2000 hertz (longitudinal vibration) Load: Own weight (about 500 grams) Path: 30 mm / pass, 30 passes / minute Loading time: 10 minutes

Test / Evaluation Results Example-1 (Secondary Hardening Abrasive Abrasive) Sample: Secondary Hardening Abrasive Abrasive Result Made According to the Method of Preparing Abrasive Abrasive Materials and Secondary Hardening Treatment described above Cutting Thickness: 0.5-0.7 mm Wear on the abrasive side: approx. 0.6 mm Surface finish: Smooth

Example 2 (Secondary Hardening Grinding Abrasive Containing Abrasive Grain Material) Sample: Abrasive particles prepared in accordance with the above-described method for adjusting the grinding / polishing material, the secondary hardening treatment method, and the method for mixing the abrasive material. Secondary hardening treatment with material Grinding and polishing material Results Cutting thickness: 0.8-1.0 mm Wear on grinding and polishing material side: Approximately 1.5 mm Surface finish: Slightly rough

Comparative Example (Grinding Abrasive Made of Inorganic Fiber Reinforced Resin According to Known Method) Sample: Grinding Abrasive Result Produced According to Preparation Method of Grinding Abrasive Material Described Above Cutting Thickness: 0.1-0. 2 mm Abrasion on grinding / abrasive side: approx. 0.5 mm Surface finish: smooth If the above results are evaluated in general, the effect of improving the grinding and polishing capacity by the secondary hardening treatment is clear, and further grinding by mixing abrasive particles Additional improvements in Noh are also recognized.

[0018]

[Effects of the Invention] Even though it is a grinding and polishing material made of an inorganic fiber hardened tree, it has a particularly excellent effect in rough cutting and polishing of high hardness materials.

[Brief description of drawings]

FIG. 1 is a perspective view (FIG. 2) A- of a hardened abrasive.
It is a B sectional view.

FIG. 2 is a perspective view showing a hardened grinding abrasive.

FIG. 3 is a temperature-time relationship diagram of secondary heat treatment.

[Explanation of symbols]

1 Hardening / Grinding Abrasive 2 Inorganic Fiber 3 Resin Part 4 Unreacted Part that Ideally Shows the Soft Part of Resin 5 Hard-Soft Conversion Zone that Ideally shows the Unhardened Soft Part 6 Cutting Element Tipped Edge T Secondary Treatment Hot air temperature (℃) H Elapsed time of secondary treatment (Hr) H ₁ First stage heat treatment process H ₂ Second stage heat treatment process H ₃ Third stage heat treatment process OFF Heat cutoff, slow cooling process

Claims (3)

[Claims] 1. An inorganic fiber selected from the group consisting of ceramics hard and brittle materials such as glass fiber, alumina fiber, silicon carbide fiber, zirconia fiber, silicon nitride fiber; epoxy resin, unsaturated polyester resin, vinyl ester resin. ，
Made of an inorganic fiber reinforced resin that is a secondary curing treatment of the cured resin portion of a grinding and polishing material processed from a molded body that has been primarily cured with a thermosetting resin selected from the group consisting of bismaleimide Grinding and polishing material 2. An inorganic fiber reinforced resin obtained by curing an inorganic fiber with a thermosetting resin, wherein an abrasive grain material is contained in the cured resin portion in an amount of 5 to 50% by volume based on the cured resin portion. Grinding and Abrasive made of inorganic fiber reinforced resin 3. An inorganic fiber reinforced resin grinding / abrasive material is used.
The secondary-cured inorganic fiber according to claim 1 or 2, wherein the desired additional abrasive polishing material is obtained by exposing it to a circulating hot-air oven at a temperature of 350 ° C to 350 ° C for 1 to 5 hours and then leaving it to slowly cool. Manufacturing method of grinding and polishing material made of reinforced resin