JPS59227777A - Manufacture of ceramics - 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 Application of the Invention] The present invention relates to a method for manufacturing high strength and reliable ceramics.

[Background of the invention]

Conventional hot pressing methods for ceramics apply static pressure, which causes problems such as insufficient close packing of particles and insufficient adhesion of particles, resulting in poor ceramic yield after firing. The disadvantage is 11) that it is not possible to produce high-quality, highly reliable ceramics.

[Purpose of the invention]

The purpose of the present invention is to provide a method for producing high-quality, highly reliable ceramics with close packing by performing pressure firing while applying ultrasonic vibration in a non-acidic atmosphere. We are committed to providing this.

[Summary of the invention]

The gist of the present invention resides in a method for manufacturing ceramics, characterized in that pressure firing is performed in a non-oxidizing atmosphere while applying ultrasonic vibrations.

That is, in the hot pressing method for ceramics, the pressing force is static pressure, so close packing of particles does not proceed smoothly, the strength varies widely, and the reliability of the material is low. Therefore, it is difficult to manufacture highly reliable and highly uniform ceramics. Therefore, in order to improve the close packing of ceramics and produce highly reliable ceramics with no variation in ceramic strength, it is necessary to perform pressure firing while applying ultrasonic vibration in a non-oxidizing atmosphere. becomes.

In other words, by applying ultrasonic vibration, the interfacial energy between particles is not high (nF), and particle movement occurs, so close-packed photocarbonization of particles progresses more easily and uniformity can be measured. . Therefore, it is possible to produce high-quality, highly reliable ceramics that have excellent strength and stability.

Regarding the ultrasonic frequency, when the ultrasonic frequency is IKH1 or less, the influence of vibration on close-packed phototenization is small and there is no effect. When the ultrasonic frequency exceeds 20 KHz, there are problems in that the vibration becomes large, which makes it difficult for the particles to move, and the adhesion of the particles is broken, making it difficult to bake. Therefore, the range of the ultrasonic frequency from 1KH2 to 20KH2 is appropriate, and is effective for uniform close-packed phototemperization.

[Embodiments of the invention]

Examples of the present invention will be described below. FIG. 1 shows the application of ultrasonic vibration to the pressure rod of a hot press. The configuration consists of an AC oscillator lO, a ferrite vibrator 9, a coil 8 wound around the ferrite vibrator, a vibration amplifier 7, and a contactor 6. The vibration transmitted from the contactor 6 is applied to the pressure rod 1, and the vibration is applied to the ceramic 5 placed in the non-oxidizing atmosphere chamber 4 and inserted into the graphite jig 3 via the pressure rod holder 2. This is a method of pressurized firing while applying For ceramics, silicon carbide with a sintering aid added is used, and it is heated in a vacuum.
Heated with l'orr and weighed 50kg at about 19001Z"
After applying a pressure of f/crB' and simultaneously applying ultrasonic vibration of 10KH2, the temperature was raised to 2000C, which is the firing temperature.
Pressure was further applied to 200 Kff/cr1f, and the pre-ultrasonic vibration was maintained at 10 KH2 for 1 hour.

Thereafter, the ultrasonic vibration was stopped, the pressurization was released, and the furnace was cooled.

The fired ceramics were taken out from the apparatus, cut into bending test pieces (3 m width x 36 + w + length), and finished with diamond polishing. The bending test pieces were taken at the center and end sides of the silicon carbide in order to check whether the entire silicon carbide was subjected to uniform close-up photohardening.

Figure 2 shows the positions of bending test pieces taken from various positions on silicon carbide. Figure 3 shows the conventional method, and Figure 4 shows the bending strength results of the present method. As can be seen from the figure, the bending strength of the conventional method shows a high strength of 1200 MPa at the center, but there is a large difference at the edges, ranging from 1000 MPa to 1100 MPa, with a maximum difference of 200 MPa. However, there are also problems from the standpoint of high quality and high reliability.

However, as shown in the figure, with this method, there is almost no difference in the overall bending strength, which is 1140 MPa to 1200 MPa.
This shows a very stable bending strength, and it can be understood that uniform-closest optical toughening of the entire ceramic was achieved. Therefore, according to the example, by performing pressure firing while applying ultrasonic vibration, filling progresses smoothly, and uniform close-packed optical hardening can be achieved throughout the ceramic, resulting in high quality and high reliability. It turned out to be a very effective means for producing ceramics.

〔Effect of the invention〕

According to the present invention, in a net press method in which ceramics are pressure fired in a non-oxidizing atmosphere, by performing pressure firing while applying ultrasonic vibration, close-packed photothermization, which is a drawback of the conventional method, can be achieved. It improves the retention of ceramics after firing due to insufficient adhesion and adhesion, and achieves uniform close-up photohardening over the entire ceramic, resulting in small differences in mechanical properties and high quality and reliability. Since it is possible to produce ceramics with a high temperature, it has excellent effects even when applied to various composite ceramics.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view showing where ultrasonic vibrations are applied to a pressure rod according to an embodiment of the present invention, Figure 2 is a state diagram showing the position of taking ceramic bending test pieces, and Figure 3 is a conventional method. FIG. 4 is a graph showing the bending test results in the method of the present invention. 1... Pressure rod, 2... Pressure rod holder, 3... Graphite jig, 4... Vacuum chamber, 5... Ceramics, 6... Contact, 7... Amplifier , 8... Coil, 9... 7 eight oscillator, lO... AC oscillator, 11... Silicon carbide substrate, 2゜13.14, 15, 16.17...
・Bending test piece collection Fig. 1 Sugar Fig. 3 Fig. ω (2) Track 11゛~b Capsule removal position

Claims (1)

[Claims] 1. A method for manufacturing ceramics, which is a hot press method in which ceramics are fired under pressure in a non-oxidizing atmosphere, characterized by performing pressure firing while applying vibrations.