JPS6268279A - Material bond polishing sheet and manufacture thereof - Google Patents

Abstract

PURPOSE:To enhance the polishing characteristic of a metal bond polishing sheet, by dispersing a part of nickel into a copper-tin group metal bond to precipitate and diffuse it as a hard nickel-tin group intermetal compound. CONSTITUTION:A mixture of copper-tin group metal powder and abrasive grain is sintered, in a nonoxidized atmosphere under pressurization at a temperature of 700 deg.C to 950 deg.C, to form a plate-like sintered material. This sintered material is rolled into a sheet-like shape, and the thus obtained rolled sheet is covered at its outer surface with nickel. Then, the nickel covered rolled sheet is heated at 750 deg.C to 990 deg.C in a nonoxidized atmosphere to diffuse a part of nickel within a copper-tin metal bond to precipitate and disperse its as a hard-nickel group intermetal compound.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a metal-bonded abrasive sheet particularly suitable for surface precision grinding and cutter blades, and a method for producing the same.

Note that the term "polishing" used in this specification is interpreted in a broad sense and is a general term including polishing, grinding, and cutting.

Metal bonded abrasive sheets suitable for conventional technical surface precision grinding and cutter blades, especially abrasive sheets using abrasive grains such as diamond and cubic boron nitride (hereinafter referred to as "super abrasive grains") Copper-tin based metal bond products, products in which super-ground grains are deposited nine times on a copper plate or stainless steel wire mesh, etc., and products with only an electrodeposition layer are known.

The grinding characteristics of copper-tin metal bond products can be improved by increasing the tin content in the metal bond. However, such a modification method results in a material that is hard and brittle. Therefore, in order to produce an abrasive sheet with excellent abrasive properties, a powder compacting process must be used. This compaction process requires a molding load of 4 to 6 tons/7, so there is a limit to the production of large sheets. Furthermore, when used as a cutter blade, it is difficult to create a thin molded body in the powder compacting process, making it unsuitable for a thin-blade cutter.

By adding nickel to the copper-tin metal bond, a hard nickel-tin intermetallic compound can be generated within the bond to improve the polishing properties, but it is still difficult to obtain a thin compact. be.

In addition, those made by electrodeposition have excellent polishing properties, but have a drawback in terms of service life because they contain only one layer of super-abrasive grains.

Problems to be Solved by the Invention An object of the present invention is to solve the above-mentioned difficulties of the prior art and to provide a sheet-like abrasive material having excellent abrasive properties.

Another object of the present invention is to provide an industrially advantageous method for producing a sheet-like abrasive having excellent abrasive properties.

The object of the present invention as described above is to use a sintered and rolled body of copper-tin metal powder and grinding abrasive grains as a base material; This is achieved by a metal bonded abrasive sheet having a nickel coating on its surface, and a part of the nila gel forming a nickel tin-based intermetallic compound in the base material and being dispersed and precipitated.

This metal bond abrasive sheet is used for the following processes (a), naka)
, (c), and (b).

(a) A mixture of copper-tin metal powder and grinding grains is sintered under pressure at 700 to 950°C in a non-oxidizing atmosphere to obtain a plate-shaped sintered body; (c) applying nickel coating to the obtained sheet-shaped rolled body, and (ii) rolling the nickel-coated rolled body into a non-oxidizing atmosphere at 750 to
Heat at 990°C.

In the metal bond abrasive sheet of the present invention, a nickel coating is formed on a sintered rolled base material consisting of grinding abrasive grains and a copper-tin metal bond, and a portion of the nickel is diffused into the copper-tin metal bond. It has excellent polishing properties because it is precipitated and dispersed as a hard nilagel-tin-based intermetallic compound within the base material.

As the copper-tin based metal pound, one having a tin content of 0.5 to 8% by weight is preferable. If the tin content is too low, the resulting sheet will have poor abrasiveness, while if it is too high, the sheet will become hard and brittle. The blending ratio of the grinding abrasive grains to the metal bond is 1 to 17% by weight, preferably 8 to 11% by weight, based on the weight of both compounds.

The grinding abrasive grains are not particularly limited, but are preferably super-abrasive grains such as diamond and cubic boron nitride, or a mixture of super-abrasive grains and other general grinding grains.

The nickel coating is formed on both sides of the 7-piece sintered rolled body,
The amount is such that the sum of the thicknesses of the coating layers on both sides is preferably 3 to 15%, more preferably 6 to 1% of the total thickness of the abrasive sheet.
Set it to 2%.

Using copper-tin-nickel powder having the same composition as the copper-tin-nickel metal bond in the abrasive sheet of the present invention,
When sintering and rolling, cracks occur during the rolling process, making it difficult to manufacture thin abrasive sheets. However, according to the method of the present invention, sintering and rolling are performed using a copper-tin metal pound with relatively excellent malleability, the obtained rolled sheet is coated with nickel, and then heated to coat the nickel. By diffusing the metal bond into a copper-tin based metal pound, it is possible to produce a thin metal bonded abrasive sheet with excellent abrasive properties.

Next, the method for manufacturing the abrasive sheet of the present invention will be specifically explained.

(B) Sintering step Copper-tin metal powder (tin content ii 0.5-18% by weight),
Diamond or cubic boron nitride, or materials mainly composed of these and other general grinding abrasive grains, are mixed in a predetermined ratio, and the mixture is heated under pressure in a non-oxidizing atmosphere to 700%
A plate-shaped sintered body is obtained by heating to ~950°C. For example, the mixture of the metal powder and grinding abrasive grains is placed flat in a graphite mold (depth: 0.4 to 2.0 m), covered with a lid, and placed on top of the mixture for 5 to 50 m. ! Apply a load of iI788 degrees and hold at 700-950° C. for 30-60 minutes in a hydrogen atmosphere. The thickness of the sintered body can be about 0.3 to 1.8 days.

(o) Rolling process The above sintered body is rolled, and the thickness of the final abrasive sheet is 3 to 1
Obtain a 5-inch thin rolled metal body. Rolling can be carried out according to conventional methods.

(c) Nickel Coating Nickel coating is applied to both sides of the above-mentioned rolled body by electroless plating, electrolytic plating, or the like. This nickel coating provides the final thickness. As mentioned above, the total thickness of the two nickel coatings is preferably 3 to 15% of the thickness of the abrasive sheet, more preferably 6 to 12 inches. If the amount of nickel coating is too large, cracks are likely to occur in the rolling step (e) below, and if the amount of nickel coating is too small, the amount of nickel-tin intermetallic compound formed will be small, making it impossible to obtain the desired polishing properties.

2) Heat diffusion process The nickel-coated rolled body is heated for 75 minutes in a non-oxidizing atmosphere.
It is heated to 0 to 990°C to diffuse a portion of the coated nickel into the rolled copper-tin metal body that is the base material. For example, a nickel-coated rolled product is sandwiched between graphite plates and heated to 750°C in a hydrogen atmosphere.
Hold at ~990°C for 5 hours. The diffused nickel forms a hard nick-tin intermetallic compound in the metal pond of the rolled body, and is dispersed and precipitated.

(e) Second rolling process Since the surface of the abrasive sheet obtained as described above is somewhat uneven, it is generally rolled lightly again or double-sided lapped to remove the unevenness on the surface and at the same time accurately adjust the thickness. value.

(to) Finishing process The rolled abrasive sheet is cut into sizes suitable for use.
An abrasive sheet product is produced by heating to remove distortions caused during rolling or double-sided lapping. To remove this strain, the abrasive sheet is sandwiched between graphite plates again and heated to 700 to 950°C for 3 hours in a hydrogen atmosphere.
It may be held for 0 to 60 minutes.

Effects of the Invention In the abrasive sheet of the present invention, a nickel coating is formed on a sintered rolled base material consisting of grinding abrasive grains and a copper-tin metal pound, and a portion of the nickel is diffused into the copper-tin metal pound. It has excellent polishing properties because it is precipitated and dispersed as a hard nick-rutin-based intermetallic compound.

In manufacturing this abrasive sheet, a sintered body made of abrasive grains and a copper-tin metal pound is rolled, and then a nickel coating is formed on the rolled body.

Therefore, in the rolling process, the sintered body does not crack and does not contain nickel components, so that it is possible to obtain an abrasive sheet with industrial advantages.

Example The present invention will be specifically described below with reference to Examples.

Example 1 Copper-tin (tin-containing fjk 10 parts by weight) atomized powder (≠
150 or less)... 97.2 parts by weight Diamond powder (12-25 μm)... 1.4# Silicon carbide powder (+2500)... 1.4# were mixed well and placed in a graphite mold (140X140X0. 7))
Place it flat in the container, cover with a graphite lid, and place 3ky (15
, 3i/cr/l'), placed in a furnace, and heated in a hydrogen atmosphere (temperature 1i 770±10°C, holding time 4
5 minutes) to obtain a plate-shaped sintered body with a thickness of 0.5 wm.

This sintered body was rolled to obtain a rolled body having a thickness of 95±4 μm. This rolled body was plated with nickel to a thickness of 10 μm (5 μm on one side) using a sulfamic acid Nigel plating bath.

The nickel-plated rolled body is sandwiched between graphite plates and heated in a hydrogen atmosphere (warm 870±10"C, holding time 75 minutes), and the nickel-plated layer is placed in the copper-tin base metal. was allowed to diffuse to form a nick-rutin intermetallic compound.

This sheet has a thickness of 110 ± 10 μm, and the surface is a little rough, so it was lightly rolled to a thickness of 105 ± 4 μm.
And so. This sheet has an outer diameter of 8 ol III 11 and an inner diameter of 25
．． I punched it out into a 4m donut shape and obtained a blade.

This blade still has some distortion from rolling, so it was sandwiched between transformed lead plates and heated in a hydrogen atmosphere (temperature 820±1
0° C., holding time for 45 minutes) to obtain flatness.

This blade was held between a 70 mφ flange and a cutting test was conducted under the following conditions.

For comparison, a blade similar to the rolled body (thickness: 105±4 μm) before being coated with nickel was prepared and tested.

Work material: 3.5 wMX 6 x 50 rectangular polycrystalline ferrite The above rigid material is pasted on a graphite plate with a bond, and
The side of the graphite plate to which the rigid material was not attached was similarly pasted onto a steel plate to form a rigid material sample.

Cutting machine used: Electrolytic discharge slicing machine EMS-1258 manufactured by Applied Magnetic Research Institute Cutting method: Down cut grinding Fluid: Water-soluble chemical type (50 times diluted) Electrolytic discharge conditions: AC, 8V, 0. IA cutting conditions: 4.50 Orpm, pitch 9.511
11.3.71 The results of the EI depth test were as follows.

Main cutting load increase amount (increase t of grindstone shaft current value) 5w1/□
10machiga 30flEI/ml! 60frmlk
RInvention product -0.01A 0.02A O
, 03A comparative example 0. IA 0.16A Maximum size of chipping during damage (chips falling off around the cut surface) 30 t12/ml 601EII/m1J1
Inventive product 40 μm 50 μm (Top surface of cut surface) Main wear (during 400 pas+s cutting) Inventive product 280 μm Example 2 Copper-tin (tin content 5 parts by weight) atomized powder (+150
(below)... 89.1 Heavy lid cast iron powder (
(4t5o or less)...9.9 Diamond powder (12-25μm)...1.0 parts by weight were mixed well, placed in a graphite mold as in Example 1, and heated in a hydrogen atmosphere (temperature 910℃). ±10° C. for 35 minutes) to obtain a plate-shaped sintered body with a thickness of Im.

This sintered body was rolled to obtain a rolled body having a thickness of 150±5 μm. This rolled body was plated with nickel to a thickness of 10 μm (5 μm on one side) in a nickel sulfamate plating bath.
Sandwiched between graphite plates and heated in a hydrogen atmosphere (temperature 970±10℃)
(holding time: 60 minutes) to obtain a sheet of 160±10 μm. This sheet was punched out to a diameter of 100 ial to obtain a sheet with incisions of 2.5 mm in width and 40 mm in length at four equal intervals from the periphery.

This sheet was attached to a flat polishing plate using a rubber thread adhesive. When this grinding tool was used to grind a flat piece of glass with a surface roughness Rmax = 18 μm that had been rough-ground, the following results were obtained.

Polishing machine: Oscar type glass polishing machine Glass type: B
K-7,70 Ratio [Glass grinding amount (μm) / Sheet wear t (ATl): l: Comparative Example 1 A rolled sheet was obtained with the same composition as in Example 2, and punched into a diameter of 100 pieces without applying nickel coating, and notches were made. A grinding experiment was conducted in the same manner as in Example 2, and the results were as follows.

Grinding amount for 5 minutes = 80 μm Surface roughness after 5 minutes: Rmax = 1.6 μm Grinding ratio =
150

Claims (1)

[Claims] 1. The base material is a sintered and rolled body of copper-tin based metal powder and grinding abrasive grains, and the surface thereof is coated with nickel, and a part of the nickel is contained in the base material as nickel-tin. A metal bond abrasive sheet characterized by forming and dispersing precipitated intermetallic compounds. 2. A mixture of copper-tin metal powder and grinding grains is sintered under pressure at 700 to 950°C in a non-oxidizing atmosphere to obtain a plate-shaped sintered body, and the sintered body is formed into a sheet. A method for producing a metal bonded abrasive sheet, which comprises rolling the resulting sheet-like rolled product into a shape, coating the obtained sheet-like rolled product with nickel, and heating the nickel-coated rolled product at 750 to 990°C in a non-oxidizing atmosphere.