WO2012086679A1 - Inorganic medium for barrel polishing - Google Patents

Abstract

Provided is an inorganic medium for barrel polishing, said inorganic medium enabling coarse finishing while exhibiting superior abrasion resistance. The inorganic medium for barrel polishing has a significant effect on costs and environmental impact because the sludge generated during barrel polishing is treated as industrial waste, as well as enabling coarse finishing and exhibiting superior abrasion resistance. In order to obtain the inorganic medium, a mixed material of argillaceous particulates and polishing particles is sintered. The inorganic medium contains at least 60-80wt% aluminium oxide, 10-30wt% silicon dioxide, 4-8wt% zirconium oxide, and 1-3wt% calcium oxide.

Description

Inorganic media for barrel polishing

The present invention relates to an inorganic medium for barrel polishing used for barrel polishing performed for deburring, rounding, smoothing, glossing and the like of articles to be polished.

Barrel polishing media (also called “abrasive stone”) is a polishing force formed into an arbitrary shape such as a sphere, cylinder, triangular pyramid, triangular prism, etc. It is a small particle having. This barrel polishing medium is generally composed of an abrasive mainly responsible for the polishing force and a binder that essentially contains the abrasive and constitutes a grinding stone.

An inorganic medium is formed by sintering a mixed material of abrasive grains such as alumina and an inorganic binder such as bauxite, and is inexpensive and has high polishing power. It is often used for rough finish polishing (see Patent Documents 1 and 2).

By the way, in barrel polishing, a mass composed of an article to be polished, a polishing media and polishing water is put in a polishing tank, and the polishing layer is rotated, revolved, or vibrated, or the bottom is rotated to rotate the mass. This is done by flowing. That is, deburring, rounding, smoothing, glossing, etc. of the article to be polished are performed by the frictional force between the article to be polished and the media generated as a result of the mass flow. Such barrel polishing has been widely used in the manufacturing process of articles since it can process a large number of articles having complicated shapes at a time. However, since the sludge generated by polishing is treated as industrial waste, there is a problem that the impact on the environment is large and the cost is high.

Japanese Patent Laid-Open No. 10-146749 Japanese Patent Publication No. 44-23873

An object of the present invention is to provide an inorganic medium for barrel polishing that enables rough finish polishing and is excellent in wear resistance.

In order to achieve the above object, the barrel polishing inorganic medium according to the present invention is a sintered barrel polishing inorganic medium comprising 60 to 80% by weight of aluminum oxide and 10 to 30% by weight of dioxide dioxide. It is characterized by containing at least silicon, 4 to 8% by weight of zirconium oxide, and 1 to 3% by weight of calcium oxide.
In the present invention configured as described above, the inorganic material for barrel polishing as a sintered body contains 60 to 80% by weight of aluminum oxide as a main component and 4 to 8% by weight of zirconium oxide as a component. In addition, it is possible to achieve an improvement in wear resistance while enabling rough finish polishing.

In the present invention, preferably, the sintered body is a sintered body obtained by sintering a mixed material including clayey fine particles and abrasive particles.

The present invention realizes improvement in wear resistance performance while enabling rough finish polishing, thereby realizing cost reduction and environmental load reduction by reducing industrial waste.

It is a perspective view which shows the example of the inorganic medium for barrel grinding | polishing by embodiment of this invention. It is a figure which shows the experimental result of the wear rate with the inorganic media for barrel polishing to which this invention was applied, and the media of a comparative example. It is a figure which shows the experimental result of the grinding | polishing amount of the inorganic medium for barrel polishing to which this invention was applied, and the medium of a comparative example.

Hereinafter, an inorganic medium for barrel polishing according to an embodiment of the present invention will be described. FIG. 1 is a perspective view illustrating an example of an inorganic medium for barrel polishing according to an embodiment of the present invention.
The inorganic medium for barrel polishing according to the present embodiment is formed into an arbitrary shape such as a spherical shape, a cylindrical shape, a triangular pyramid shape, a triangular prism shape, etc. of several millimeters to several tens of millimeters according to the purpose of polishing. An example of the shape is shown in FIGS. 1A is a triangular prism shape, FIG. 1B is a shape obtained by obliquely cutting an intermediate portion of the triangular prism, FIG. 1C is a spherical shape, and FIG. 1D is a cylindrical shape. is there.

In the inorganic media for polishing according to the embodiment of the present invention (hereinafter, also simply referred to as “media” or “media of the present invention”), the mixed material of clay particles and abrasive particles is 60 to 80% by weight (polishing). Aluminum oxide (Al ₂ O ₃ ) in a weight ratio relative to the weight of the inorganic medium for use, 10 to 30 wt% silicon dioxide (SiO ₂ ), 4 to 8 wt% zirconium oxide (ZrO ₂ ), 1 to The mixture is adjusted to contain at least 3% by weight of calcium oxide (CaO), and the mixed material having such a composition is sintered. A medium obtained by sintering a mixed material having such a composition has 60 to 80% by weight of aluminum oxide (Al ₂ O ₃ ), 10 to 30% by weight of silicon dioxide (SiO ₂ ), 4 ˜8 wt% zirconium oxide (ZrO ₂ ) and 1 to 3 wt% calcium oxide (CaO). As shown in the following examples, the wear rate can be greatly improved while maintaining the polishing force as compared with the conventional media.
Here, the clayey fine particles are fine particles that can be collected to form a clay. For example, it means a state in which aluminum oxide, zirconium oxide, silicon dioxide, calcium oxide, magnesium oxide and the like are mixed. The abrasive particles may be particles containing at least aluminum oxide.

Next, the media of Examples 1 to 3 according to the present invention will be described together with the media of Comparative Examples 1 and 2 for comparison with the present invention. Comparative Example 1 is an example of a medium composition that has been widely used for rough finishing. Comparative Example 2 is an example in which abrasive particles are mixed with a binder mainly composed of aluminum oxide used for gloss finish so that the polishing power can be roughly finished. Table 1 shows the ratio of each component in Examples 1 to 3 and Comparative Examples 1 and 2.

The media of Examples 1 to 3 and the media of Comparative Examples 1 and 2 can be obtained by a method similar to the conventional method as described below, for example. Note that the manufacturing method is not limited to this, and a method conventionally conventionally used can be selected as appropriate according to the shape of the medium determined according to the purpose of polishing.

First, each raw material is mixed so as to achieve each blending ratio in Table 1, and kneaded as a slurry to which about 15% of water is added, and the obtained slurry is put into an extrusion molding machine, and one side is about 15 mm. Are cut into a length (the height of the triangular prism) of about 15 mm and dried to obtain a media green body.

Next, the obtained media green body is put into a heat-resistant container, and each medium is obtained by firing at a temperature of 1300-1500 ° C. for about 2 hours in a temperature-controlled firing furnace. In this case, if the sintering temperature is lower than 1300 ° C., the strength of the media decreases, and if the firing temperature is higher than 1500 ° C., the shape of the media cannot be maintained. In addition, since a suitable firing temperature (for example, about 1400 ° C.) within the temperature range of 1300 to 1500 ° C. needs to be adjusted depending on the composition of the media, when trying to fire media of the first component or shape, Needless to say, it is necessary to prepare a sample in advance and conduct a firing test to find a suitable firing temperature.

12 liters of the obtained media was put into a barrel polishing apparatus (Power Roll Flow EVFX-1) manufactured by Shinto Kogyo Co., Ltd. together with 10 liters of water and 7 milliliters of a compound. Workpieces are cylindrical carbon steel with a diameter of 22 mm and a length of 15 mm (S45C JIS standard) (C: 0.42 to 0.48%, Si: 0.15 to 0.35%, Mn: 0.60 to 0.90%, P: 0.03% or less , S: 0.035% or less), and a 1 hour polishing test was conducted. FIG. 2 shows the result of the wear rate obtained by measuring the rate of weight reduction of the grinding stone. FIG. 3 shows the result of the polishing amount (assuming the polishing power) obtained by measuring the weight reduction amount of the test piece. 2 and 3, E1, E2, and E3 show the results of Examples 1, 2, and 3, respectively, and CE1 and CE2 show the results of Comparative Examples 1 and 2, respectively. The vertical axis in FIG. 2 indicates the wear rate (%), and the vertical axis in FIG. 3 indicates the polishing amount (mg).

From the results of FIG. 2, the wear rate is 8.62% in Comparative Example 1 (an example widely used in the past), whereas it is 5.20% in Comparative Example 2 (an example of a composition mainly composed of aluminum oxide). It is shown that it is improved (about 60% of Comparative Example 1) over Comparative Example 1. In Example 1, by adding a zirconium oxide component, the wear rate can be 3.34%, which is a significant improvement over Comparative Examples 1 and 2 (about 39% of Comparative Example 1, Comparative Example 2). (About 64%). In the cases of Examples 2 and 3, the same results as in Example 1 were obtained.

Further, from the result of FIG. 3, Comparative Example 1 has a polishing amount of 207 mg and Comparative Example 2 has a polishing amount of 191.5 mg, whereas Example 1 has a polishing amount of 162.5 mg, and the wear rate is reduced. At the same time, the polishing power decreases. In general, it is said that the wear rate and the polishing force (polishing amount) are in a proportional relationship. However, when the polishing amount with respect to the media wear rate of 1% is compared, it is 24.0 in Comparative Example 1 and in Comparative Example 2. While it was 36.8, it was 48.7 in Example 1, and it was confirmed that the polishing efficiency of Example 1 was very high. In the case of Examples 2 and 3, substantially the same result as in Example 1 was obtained, and it was confirmed that the polishing efficiency of the Example was very large.

As described above, the media of Examples 1 to 3 achieve improved wear resistance while enabling rough finish polishing. Compared to the conventional media (Comparative Example 1), the wear rate is about 40%, so the service life is more than doubled and the amount of sludge generated is reduced, greatly reducing the amount of industrial waste generated. , Can contribute to the reduction of environmental impact.

The present inventors have found that wear resistance is improved by adding zirconium oxide having high toughness to aluminum oxide having low toughness (toughness), and based on this finding, aluminum oxide is used as the main medium of media. By using a composition in which the zirconium oxide component was appropriately added as a component, it was possible to obtain a range in which the wear resistance performance was improved while enabling rough finish polishing.

An inorganic medium for barrel polishing to which the present invention is applied is obtained by sintering a mixed material of clayey fine particles and abrasive particles to form the above-described component states of aluminum oxide, silicon dioxide, zirconium oxide, and oxidation. By including calcium, it is possible to improve the wear resistance while enabling rough finish polishing, thereby realizing cost reduction and reduction of environmental load by reducing industrial waste.

The above-mentioned media is not limited to a triangular prism shape, but a spherical shape, a cylindrical shape, an elliptical cross section, various pyramid shapes including a triangular pyramid shape, and various types including a triangular prism shape. A prismatic shape or the like may be used. In addition, it seems that a cylinder or a prism is cut by a plane having a predetermined angle with respect to a plane perpendicular to its axis (here, the axis means a direction orthogonal to a cross section, for example, a circle or a triangle). It may be a simple shape. Further, the side surface of the substantially triangular prism shape may be recessed inward, and each apex portion constituting the substantially triangular prism shape triangle may be an arc shape (see, for example, Japanese Patent Application Laid-Open No. 2003-231053). These shapes may be cut by a plane having a predetermined angle with respect to a plane perpendicular to the axis.

1 Inorganic media for barrel polishing E1, E2, E3 Results of Examples 1, 2, 3 CE1, CE2 Results of Comparative Examples 1, 2

Claims (2)

An inorganic medium for barrel polishing that is a sintered body,
For barrel polishing, comprising at least 60 to 80 wt% aluminum oxide, 10 to 30 wt% silicon dioxide, 4 to 8 wt% zirconium oxide, and 1 to 3 wt% calcium oxide Inorganic media. 2. The inorganic medium for barrel polishing according to claim 1, wherein the sintered body is a sintered body obtained by sintering a mixed material including clayey fine particles and abrasive particles.

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