JPS60176969A - Manufacture of plzt - 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] The present invention relates to a method for producing pLZT.

Optical shatter element, light modulation element, transparent buzzer.

There are various methods for manufacturing PLZT used in transparent speakers and the like, and one example of the method used is as follows.

Namely, hot press method, PbO atmosphere firing method.

This is a hot isostatic firing method.

In the hot press method, 1 synthesized raw material powder is granulated and then press-molded into 2 cylindrical shapes at a pressure of 200 to 500 mm. Next, the molded powder is placed in an AI, O, hot press mold, and the mold is filled with coarse-grained Al2O powder as a mold release agent, and fired under pressure.

In addition, in the PI)O atmosphere firing method, the molded PI, ZT
was placed in an Al2O3 crucible, and the outside of the crucible was filled with PbZr0B + PbO2 powder, and A1□0. Cover it and put it in a large A1!03 crucible.

This is a method in which oxygen is passed between the crucible and the Al, O, and cover for sintering.

In addition, in the hot isostatic pressure firing method, PLZ is heated using high pressure gas.
Isotropic pressure is applied to T, and heat treatment is performed at the same time.

In the above prior art, A, 120. In the hot press method using large-sized materials and the PbO atmosphere firing method, Al2O3
P that easily absorbs pbo, reacts with PLZT, or has poor control over the amount of PbO in PLZT, which is preferable.
LZT cannot be obtained. Especially when translucency is required in PLZT, excessive amount of pbo is added to PLZT,
At the same time as pbo volatilizes, it eliminates pores and increases translucency, and pb.

The adjustment of the product greatly affects the value of the product and requires careful control.

In addition, the hot press method and the hot isostatic pressure method are complicated in terms of mass production and industrial implementation, and have the disadvantage that arbitrary molded products cannot be obtained.

As a result of intensive research by the two inventors, they came up with the following invention.

That is, in the method of manufacturing PLZT and doped PLZT, the periphery is formed with a refractory whose main component is MgO during sintering, and sintering is performed without using any other refractory in the sintering atmosphere. This is the way to do it.

Further, as embodiments thereof, in the above invention, a method in which the sintering atmosphere is an oxidizing atmosphere and a method in which no pressure is applied during sintering have been discovered.

3. Pl for producing PLZT: +O, La2O3, ZrO2゜TlO, which will be explained in detail in the present invention below.
Put the two powders into a mold to give the desired shape, and press and mold at room temperature.

In addition, Ba, Sr, Hd, Sm, Oa, Nb,
Fe, Li.

Materials doped with Hθ or the like can also be treated as objects of the present invention.

The above P T and Z T were surrounded by a large plate-like surface made of MgO, and heated at 1100-1200°C 1 n ~ 40 H.
rHeat and sinter. The MgO plate may be attached to another coating material by thermal spraying or the like, or may be the MgO plate itself.

Further, the thickness of the 1Ml MgO powder plate is preferably about 5 to 20 mm.

Since the MgO plate absorbs less volatile pbo, there is no need to fill it with PbZrO3 and PbO2 as in the past, and it can be used in an open state as shown in Figure 1, making it easy to mass-produce for industrial implementation. .Also, instead of just the MgO plate, MgO powder may be applied to the bottom.

Further, the amount of excess lead added to form PLZT can be small. This is because the room is immediately filled with PBO because it is not absorbed by MgO, which is the outer wall.

゛Again. To shorten the sintering time, perform hot pressing for several hours before sintering at normal pressure.

The method of the invention may also be carried out.

By implementing the present invention as described above, the following effects can be obtained.

(1) By carrying out the present invention, the sintering process becomes simple and it becomes possible to industrially mass-produce PLZT.

(2) Sintering can be performed without using pot press or hot isostatic pressure firing, and the manufacturing cost is extremely low.

(3) Since this method does not involve filling with Al, Oo, etc., there is no need to worry about contamination of impurities into the product.

(4) The transmittance required by PLZT was also a high value.

Example PbO, Tie, ZrO2, La2O3 powders were adjusted and mixed, placed in a 9 cylindrical mold, pressed, and then heated in a hot press for 15 minutes.
It was fired at a pressure of 0 Kr f /m and a temperature of 1200° C. for 2 hours.

Thereafter, the box was placed in a box as shown in Figure 1 made of a 7-inch thick MgO plate (1), and oxygen was introduced through the oxygen inlet (3) and heated to 1200°C in an oxygen atmosphere at normal pressure in a heating furnace (4). ,
Firing was performed for 40 hours. Particle size: 2μ, transmittance: thickness: 0.5
+am and a wavelength of 6000 W, the value was 65 excellent, which was a preferable value.

This is a preferable PL because no excessive volatilization of pbo was observed.
ZT was obtained. - There was no need to fill with stopped PbO+PbZrO3, and the sintering work could be done easily.

Comparative Example When sample (2) was placed and fired in a box made of an Al□03 plate under the same conditions as above, a preferable transmittance was not obtained because the amount of pbo volatilized was large.

[Brief explanation of drawings]

FIG. 1 shows one embodiment of the present invention. (11MgO plate (2) Sample Patent applicant: Japan Mining Co., Ltd. Agent: Patent attorney (7569) Keishi Namiyo Figure 1 1゜

Claims (3)

[Claims] (1) In a method for manufacturing PLZT and PLZT doped (hereinafter referred to as PLZT), the surrounding area is formed only with a refractory whose main component is MgO during sintering, and no refractory other than the above is used. A method for producing PLZT, characterized in that PLZT is sintered without being used in a sintering atmosphere. (2) The method for manufacturing PLZT according to claim 1, characterized in that the sintering atmosphere is an oxidizing atmosphere. (3) The method for manufacturing PLZT according to claim 1, characterized in that no pressure is applied during sintering.