JPS63227301A - Manufacture of ceramic ball - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing ceramic balls used in ball mills, pole bearings, etc.

[Conventional technology]

Since poles used in ball mills, pole bearings, etc. are required to have excellent mechanical properties such as wear resistance, ceramics are suitable as materials for the poles.

Conventionally, these ceramic balls have been produced using press molding, casting, CI P (cold static), etc.
It is manufactured by the PresS-ing method, transfer granulation method, etc.

[Problem that the invention seeks to solve]

However, ceramic balls manufactured using the press molding method tend to have annular protrusions formed when fitting the mold, and ceramic balls manufactured using the casting method tend to have protrusions formed at the casting opening. Furthermore, ceramic balls produced by the CIP method are difficult to form into spherical shapes and tend to become oval or oval. Therefore, in order to make these ceramic balls almost perfectly spherical, post-processing is required. Is required.

On the other hand, ceramic balls manufactured by the transfer granulation method have discontinuous boundaries in the poles, and cracks are likely to occur from these boundaries, resulting in problems in mechanical strength.

Moreover, in any of the above-mentioned methods, there is a problem in that the molding efficiency is extremely low when attempting to mold a small pole with a diameter of 5 m or less, for example.

The present invention has been made in order to solve the above-mentioned problems, and an object thereof is to provide a method for manufacturing ceramic balls having high mechanical strength with high efficiency.

[Means for solving problems]

The method for manufacturing a ceramic ball of the present invention has water absorbency. The method is characterized in that a ceramic material is molded into a spherical shape, a predetermined ceramic material is adsorbed in the form of a slurry onto the spherical molded body, and after drying, it is fired.

In the present invention, examples of water-absorbing ceramic materials include γ-alumina, alumina fiber, and Si.
Examples include C whiskers.

Methods for molding such water-absorbing ceramic materials into spherical shapes include press molding, cast molding, and CIP.
Although any method may be used, such as the transfer method or the transfer granulation method, the transfer granulation method that yields a spherical shaped body is preferable.

As the ceramic material that is adsorbed in the form of a slurry on this spherical molded body, there can be mentioned various ceramic materials such as alumina, zirconia, silicon nitride, aluminum nitride, and silicon carbide depending on the purpose.

Examples of the solvent used to turn these ceramic materials into a slurry include various organic solvents and organic binders.

In the present invention, a water-absorbing ceramic material;
The ceramic material to be adsorbed to this in a slurry state may be the same material, such as SiC whiskers and SiC, or γ-alumina and alumina, or may be other materials.

[Effect]

According to this method, a nearly perfect spherical molded body is first formed using an appropriate molding method, and then immersed in ceramic slurry, dried, and fired, so that no post-processing is required. - Ceramic balls with high mechanical strength can be manufactured at a high yield.

〔Example〕

The present invention will be explained in detail below.

As shown in Table 1 below, spherical molded bodies having spherical diameters shown in Table 1 below were molded by transfer granulation using γ-alumina particles or SiC whiskers as raw materials. Separately, a slurry in which alumina or silicon carbide is dispersed in an organic solvent is prepared in advance.Next, the above-mentioned spherical molded body is immersed in each slurry, and alumina or silicon carbide is coated on the inner surface and surface of the slurry. After adsorption, it was dried. At this time, vacuum may be applied to ensure uniform adsorption.The diameter of the ball body before firing obtained in this way, and the diameter of the ceramic ball manufactured by firing this pole body. ,
The specific gravity and manufacturing yield are shown in Table 1 below.

On the other hand, for comparison, silicon carbide particles were used as a raw material and formed into a spherical shape by a press molding method or a casting method, and then post-processed to form ceramic balls with ball diameters of 3, 5, 8, and 10°. Manufactured. The specific gravity and production yield of the obtained ceramic balls are shown in Table 2 below.

As is clear from Tables 1 and 2, the method of the present invention (Table 1) can produce ceramic balls with excellent mechanical strength at a high yield. On the other hand, in the conventional press molding method or transfer granulation method (Table 2), as the diameter of the ceramic balls becomes smaller, the yield decreases due to post-processing! It is written by gI.

In addition, wear tests were conducted on silicon carbide poles with a ball diameter of 3 mm manufactured by the method of the present invention and the conventional press molding method using a vibrating ball mill as follows. In other words, in an alumina pot with a volume of 2 liters, 3
Put 1 kg of silicon carbide powder with 25 mesh passes and 3000 silicon carbide poles, and heat it in a vibrating ball mill for 120 hours (
After continuous operation (for 5 days), the wear volume per pole was determined from the wear weight of the entire pole.

As a result, the wear volume per pole was 7.5X10-3c for the silicon carbide pole manufactured by the method of the present invention.
m', and the silicon carbide pole manufactured by the conventional method was 7.4XIQ-3 cm', which is almost the same.

〔Effect of the invention〕

As detailed above, according to the present invention, there is no need for post-processing, and remarkable effects such as being able to manufacture ceramic balls with high yield and high mechanical strength are achieved.

Applicant's representative Patent attorney Takehiko Suzue Procedural amendment 3, relationship with the case of the person making the amendment Patent applicant 1-26-2@4, Nishi-Shinjuku 1-chome, Shinjuku-ku, Tokyo 163, Date of amendment order Voluntary amendment 5, Amendment Column 6 of “Detailed Description of the Invention” of the subject specification, contents of amendment (1) In line 6 of page 5 of the specification, “the inner surface and”
The text has been corrected to read "within it."

that's all

Claims (1)

[Claims] A method for producing a ceramic ball, which comprises forming a water-absorbing ceramic material into a spherical shape, adsorbing a predetermined ceramic material in the form of a slurry onto the spherical molded body, drying it, and then firing it.