JPS6224969A - Honing stick for aluminum alloy and its manufacture - Google Patents

Abstract

PURPOSE:To make it possible to get excellent machined surfaces with honing sticks keeping the proper elasticity of abrasive grains because of a binder and without the damage of the primary crystal of the surface of the honing sticks and to prevent the honing sticks from clogging by binding the abrasive grains and a fine particle addition agent with no porous thermosetting flexible plastic. CONSTITUTION:The mixture of one or more kinds of silicon carbide fine particles, fused alumina fine particles, and boron carbide fine particles is used as abrasive grains, and thermosetting epoxy flexible liquid resin is used as thermosetting flexible resin. And the mixture of one or more kinds of graphite, iron oxide, and cerium oxide particles is used as a fine particle addition agent is to be 0.5mu-10mu and the weight percentage is to be 10-100pts.wt. per 100pts. wt. of abrasive grains. And in the manufacturing of a grindstone, a main agent, the thermosetting flexible resin, is mixed with a hardening agent, and then, is mixed with the abrasive grains and the fine particle addition agent by a kneader or mixing roller. Non porosity of thermosetting plastic will not cause clogging and its flexibility and the mixing of fine particle addition agent serves to get excellent machined surfaces.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a honing wheel for grinding aluminum alloys.

(Prior Art) Conventionally, as a honing stone for grinding aluminum alloy, one in which abrasive grains are bonded with a phenol resin is generally used.

(Problem to be solved by the invention) However, when processing high-silicon aluminum with a conventional grindstone, very hard particles (metallic silicon) are mixed into a soft matrix (aluminum) with high ductility.
Therefore, depending on which grinding conditions are used during processing, a decrease in dimensional accuracy, damage to metal silicon, scratches caused by abrasive grains, etc. may occur. In other words, if the grinding conditions are adjusted using a grindstone that matches soft aluminum, the metal silicon will not be able to be ground, and if the processing pressure is increased and the process is forcibly ground, the metal silicon will be damaged. In addition, when grinding with a grindstone that matches the grinding conditions to hard metal silicon, soft aluminum tends to adhere to the grindstone surface, causing clogging, and scratches caused by the abrasive grains, resulting in poor surface roughness. A good finished surface cannot be obtained.

In order to solve the above problems, this invention provides a honing whetstone for grinding aluminum alloys that does not damage the silicon primary crystals on the aluminum alloy surface, provides a good surface finish free of scratches, etc., and prevents clogging of the whetstone. The purpose is to provide.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a honing whetstone for aluminum alloy, characterized in that abrasive grains and a fine particle additive are bonded by a thermosetting flexible resin. be. The abrasive grains include silicon carbide grains, fused alumina grains, boron carbide grains,
One or more mixed particles such as diamond particles and cubic boron nitride particles are used, and the thermosetting flexible resin is a thermosetting epoxy flexible liquid resin. As the particulate additive, mixed particulates of one or more of graphite, red iron oxide, cerium oxide, chromium oxide, zirconium oxide, etc. are used, and the average particle diameter of the particulate additive is 0.5.
~10 μ and 10 to 1 per 100 parts by weight of abrasive grains
00 gravity part. When manufacturing the above-mentioned grindstone, after mixing the main component of the thermosetting flexible resin and the curing agent, abrasive grains and particulate additives are added and mixed using a kneader or a mixing roller.

(Function) The honing stone for aluminum alloy according to the present invention does not cause clogging due to the presence of pores because the thermosetting flexible resin as the binder is pore-free. In addition, this binder is flexible, and the addition of particulate additives causes slippage inside the resin, lowering the elastic modulus. As a result, the binder holds the abrasive grains with appropriate elasticity and relieves the impact on the metal silicon exposed on the aluminum alloy surface, resulting in a good finished surface with almost no damage to the metal silicon.

Furthermore, by mixing the particulate additive, the aggregate effect within the epoxy resin is effectively enhanced, and the tensile strength of the grindstone is improved. This has a positive effect on wear resistance and improves the life of the grinding wheel.

(Example) Examples according to the present invention will be described below.

1st Example Silicon carbide (GC#400) 100 parts by weight Graphite (average particle size 3μ) 40 tl 1 part Epichlorohydrin-bisphenol A type liquid epoxy resin (base resin)
20 parts heat-curing flexible curing agent 30 parts Retracting part The epoxy resin base and curing agent are mixed in advance, silicon carbide and graphite are added thereto, and the mixture is thoroughly mixed in a vacuum kneader. Next, it is poured into a rectangular mold coated with a mold release agent and cured in a 120° C. oven for 20 hours. After hardening, the grinding stone material is, for example, 60x60xl as shown in Figure 1.
The grindstone 1 is formed into a square rod shape of O.

Tensile Test A tensile test was conducted on the grindstone thus obtained, a conventional grindstone, and a grindstone not mixed with graphite. FIG. 3 shows test piece 5.

The results show that the elastic modulus is 1/1 compared to the grindstone without graphite.
10, the tensile strength was improved by 34%, and the tensile elongation at break was improved by 2.5 times. This is because graphite acts effectively and becomes a grindstone with a small elastic modulus.

Honing test Test conditions Work material: High-silicon aluminum alloy Main components (%) Si: 20. O, Fe: 1.3 Cu: 2.0. Mn:2. O Pb: 2. O, i: Dimensions of remaining workpiece: 75x40x20 Grinding test machine: Honing test machine Grinding wheel crimping crab 6 to 9/c scrap Grinding time: 2 minutes Grinding oil: Light oil Test results As shown in the table below, grinding with the example grindstone was , the grinding ratio is good, and the ground surface of the workpiece is rounded and finished well. When observing the condition of the processed surface with a microscope, damage to the metal silicon grains was observed in the case of the conventional grinding wheel and the grinding wheel without graphite, but in the example grinding wheel, there was no damage to the metal silicon grains at all, and the material was well ground together with the base material. There is.

The grinding ratio here is grinding volume/grinding wheel wear volume.

Second Example Silicon carbide (GC#400) 100 parts by weight Diamond abrasive grains (SDC325/400) 40 parts by weight Red iron (average particle size 0.5μ) 50 parts by weight 5 parts Epichlorohydrin-bisphenol A type liquid epoxy resin 2
0 parts by weight Heat-curable flexible hardener 30 [3 parts In this case as well, the material was produced in the same manner as in the first example, and the hardened grindstone material was cut into a 60x10x3 sheet shape, as shown in Fig. 2. This grindstone 2 was adhered to a base plate 4 with an adhesive 3.

Tensile test Compared to the grindstone without iron oxide, the elastic modulus of this example grindstone decreased to 12%, the tensile strength increased by 52%, and the elongation until tensile breakage increased by 3.1 times, exceeding that of the grindstone containing graphite. There is. This is because red iron is finer than graphite and wets resin better.

The honing test was carried out under the same conditions as the first eggplant example. However, only the crimp force is 1
It was set to 0 Kfl/ci.

Regarding the condition of the processed surface in this case, the metal silicon crystal was damaged with the grindstone without red iron, but no damage was observed with the example grindstone, and the finished surface roughness was about 1
/2, which is good. The amount of grinding and the grinding ratio are significantly higher than those in the first embodiment, and this is due to the effect of increased pressure and the inclusion of diamond abrasive grains.

micrograph 4(a), (b) and FIG. 518).

(b) is a photograph of the state of the workpiece surface ground by the grindstone of the second embodiment and the conventional grindstone, observed with a metallurgical microscope. FIG. 4 is 260 times larger, and FIG. 5 is 650 times larger. 6 is a damaged portion of the metal silicon crystal.

(Effects of the Invention) Since the present invention is a honing whetstone for aluminum alloys and a method for manufacturing the same having the configuration as explained above, when grinding with this whetstone, the silicon primary crystals on the surface of the aluminum alloy are not damaged, and a good condition with no scratches etc. is obtained. It has the effect of providing a good finished surface and preventing clogging of the grindstone. Furthermore, since the tensile strength of the grinding wheel increases, it has the effect of increasing wear resistance and extending the life of the grinding wheel.

[Brief explanation of drawings]

The figures show examples of grindstones according to the present invention, FIGS. 1 and 2 are perspective views of the grindstones of the first and second embodiments, FIG. 3 is a perspective view of a test piece, and FIG. 4(a). (b) is a 260x microscopic photograph of the processed surface ground with the example and conventional grindstone, and Figures 5 (a) and (b) are also 6
This is a 50x micrograph. 1.2...Whetstone 5...Test piece

Claims (10)

[Claims] (1) A honing stone for aluminum alloy, characterized in that abrasive grains and a fine particle additive are bonded together using a thermosetting flexible resin. (2) The aluminum alloy according to claim 1, wherein the abrasive grains are composed of one or a mixture of two or more of silicon carbide grains, fused alumina grains, boron carbide grains, diamond grains, and cubic boron nitride grains. Honing whetstone. (3) The honing stone for aluminum alloy according to any one of claims 1 and 2, wherein the thermosetting flexible resin is a thermosetting epoxy flexible liquid resin. (4) The aluminum according to any one of claims 1 to 3, wherein the particulate additive material is a mixed particulate of one or more of graphite, red iron oxide, cerium oxide, chromium oxide, and zirconium oxide. Honing whetstone for alloys. (5) Any one of claims 1 to 4, wherein the fine particle additive has an average particle diameter of 0.5 to 10 μm and is present in an amount of 10 to 100 parts by weight per 100 parts by weight of abrasive grains. Honing whetstone for aluminum alloys as described in section. (6) A method for producing a honing stone for aluminum alloys, which comprises mixing a thermosetting flexible resin main ingredient and a curing agent, then adding abrasive grains and particulate additives, and mixing using a kneader or mixing roller. . (7) The aluminum alloy according to claim 6, wherein the abrasive grains are composed of one or more mixed particles of silicon carbide grains, fused alumina grains, boron carbide grains, diamond grains, and cubic boron nitride grains. Manufacturing method of honing stone. (8) The method for producing a honing stone for aluminum alloy according to any one of claims 6 and 7, wherein the thermosetting flexible resin is a thermosetting epoxy flexible liquid resin. (9) The aluminum according to any one of claims 6 to 8, wherein the particulate additive material is a mixed particulate of one or more of graphite, red iron oxide, cerium oxide, chromium oxide, and zirconium oxide. Manufacturing method for honing wheels for alloys. (10) The fine particle additive has an average particle diameter of 0.5 to 10μ
and 10 to 100 parts by weight per 100 parts by weight of abrasive grains, according to any one of claims 6 to 9.
The manufacturing method of the honing stone for aluminum alloys described in Section 1.