JPS63252970A - Method of burning ceramic composition - 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] (Industrial Application Field) This invention is directed to lead oxide (hereinafter referred to as PbO), which has a high vapor pressure.
The present invention relates to a method for firing a porcelain composition for firing a laminated molded body comprising:

(Prior art) Figures 4(a) and 4(b) are published on IO June 1983, "Ceramic Dielectric Engineering", Kiyoshi Okazaki, Gakkensha, 15
Fig. 4(a) is a diagram showing a method for firing high dielectric constant porcelain containing rPbO shown in Pb4 to Pb157. This figure shows the use of a platinum crucible and platinum foil when firing (lead zirconate)-based porcelain.

In the case of this FIG.
6 is stored in layers alternately with platinum foils 105, and PbO
The sample 106 is fired while the atmosphere adjustment sample 104 is put in and the PbO atmosphere is adjusted.

In the case of FIG. 4(b), the outer crucible 110 is made of N1, and the inner crucible 107 is made of ZrO! This outer crucible 110 and inner crucible 107 have a double structure formed by
The bottom surface 111 of is made of Ni.

The sample 109 is stacked on this bottom surface 111, and the sample 109
Firing is performed while the top and bottom of the sample 109 are sandwiched between PbO atmosphere adjustment samples 109, or while excessive PbO is added during the preparation process.

(Problems to be Solved by the Invention) However, in the conventional firing method shown in FIGS. 4(a) and 4(b), the PbO vapor pressure becomes uniform within the crucible. Therefore, when firing, the optimum PbO vapor pressure cannot be obtained, resulting in a change in composition, resulting in problems such as not being able to obtain good properties, or the sample and platinum reacting and adhering to each other. Oh.

This invention solves the problems of the above-mentioned prior art.
The present invention provides a method for firing a ceramic composition that solves the problem of not being able to obtain a fired body with good characteristics.

(Means for solving problems) The present invention relates to a method for firing a porcelain composition.

3a Ti 01 series, Ca Ti Os series or 5r
TiO, based composition as the first material, and Pb Zr Ox
system, Pb Ti Os system or pb (Zr, Ti
) The step of laminating preforms in the casing with an On-based composition as a second material and varying the mixing ratio of the first material and the second material to give a gradient in PbO concentration; Spacers and blocks of the same composition are used to surround the laminate molded bodies, and the inside thereof is filled with fine powder having the same composition as each laminate molded body, and the uppermost laminate molded body is surrounded by a crucible, and the uppermost laminate molded body is surrounded by a crucible. This method introduces a step of filling the preform with fine powder having the same composition as that of the preform and firing the preform while adjusting the firing atmosphere to be the same as the PbO concentration gradient of each preform.

(Function) According to the present invention, one or more steps are introduced into the method for firing a porcelain composition, so that when the preform is fired in the casing, the PbO concentration gradient of the preform is the same as that of the preform. The firing atmosphere is adjusted so that the preform, the spacer, the block, and the fine powder shrink simultaneously, and the preform is sintered without creating any gaps between the preform, the block, and the spacer.

(Example) Hereinafter, an example of the method for firing a ceramic composition of the present invention will be described based on the drawings. FIG. 1 is a schematic diagram for explaining one example, and numeral 1 in the figure is a laminated molded body serving as a sample.

This laminated molded body 1 is placed in the center of a case 16 made of magnesia. Laminated molded body Ire
It is composed of preforms 1a to 1e formed by changing the mixing ratio of BaTiOs and PbZrO.

The preform 1a has a gaTiOs (barium titanate) component of 100 vo/%, and the preform ib has a Ba
Ti Os vs. 80vo/X and PbZrOs vs. 20vo
/%, and the preform 1c consists of Ba Ti Os vs. 50 vol X and pb Zr Os vs. 50 vol/X.
The preformed body 1d is made of Ha Ti O, 20v
ot% and Pb Zr O, from 80vo/%,
Further, the preform 1e is made of pb Zr Ox vs. 100vo
/%.

In this way, each preform 1a=1e is Ba'l'
i0. By changing the mixing ratio of Pb and Pb Zr On, a gradient in the pb concentration was created.

These preforms 1a to 1e are magnesia casings 1.
6, preforms 1e to 1a are stacked in order from the bottom.

On the outer peripheral surfaces of these preforms 1a=1e, spacers 2 and 3a are provided near the respective boundaries.

3b and 4a, 4b and 5m, and 5b and 6a are arranged one on top of the other, and a spacer 6b is arranged between the lower part of the preform and the bottom of the magnesia casing 16.

Spacers 2 to 6b are spacers for adjusting the PbO atmosphere. The spacer 2 has the same composition as the preform 11 of the laminated body 1, and the spacers 3m and 3b have the same composition as the preform ib. Spacer 4a.

4b has the same components as the preformed body 1c, and a spacer 5a.

5b has the same components as the preformed body 1d, and a spacer 6a.

6b has the same components as the preform 1e.

Among these spacers 2 to 6b, spacers 3a and 3b
Blocks 7 to 10 are interposed between the spacers 4a and 4b, between the spacers 5a and 5b, and between the spacers 6a and 6b.
~6b is fixed.

The composition of block 7 is the same as that of preform 1b,
Similarly, the composition of block 8 is as follows: preformed body 1c;
The composition of block 9 is the same as that of preform 1d, and the composition of block 10 is the same as that of preform 16.

Further, on the spacer 2, a pot 17 to be magnetically screwed
is located. The preformed body 1a is housed in the pot 17 that is screwed by the magnetic screw. The space between the magnetically screwed crucible 17 and the outer circumferential surface of the preformed body 1a is filled with fine powder 11, and the fine powder 11 is also deposited outside and below the magnetically screwed crucible 17.

Preformed body 1b, spacers 3a, 3b and block 7
The space between them is also filled with fine powder 12. Similarly, the preformed body 1c and the spacer 4&.

4b and the block 8, the space between the preform 1d and the spacers 5a and 5b% block 9, and the space between the preform 1e and the spacers 6a, 6b, and the grooves 210. ~15 are filled.

Furthermore, the bottom of the case 16 and the space? 6b, fine powder 18 is spread all over. The composition of this fine powder weight 8 is the same as that of the preformed body 1e.

Further, the composition of each of the fine powders 11 to 15 is the same as that of the preforms 1&-1e. In addition, spacer 2~
6b,! Locks 7-10. Fine powder 11-15. The pots 17 for magnetic screwing are each housed in a magnesia case 16 together with the laminated molded body l.

Each of the spacers 2 to 6b is 7QX as shown in FIG.
The overall shape of the dimensions of 7QXllllII is rectangular,
15.1111 for inserting the laminated molded body 1 into the center part
1 hole 20 is formed.

In addition, the shape of each 10 pieces 7 to 10 is formed as shown in Fig. 3, and has a rectangular frame shape, with a hole 3 in the center.
0 is formed. This hole 30 is filled with the laminated molded body l and the fine powders 12 to 15.

Next, first, the procedure for preparing the material for the laminated molded body l will be described.

BaTiO, the components of which are chemically highly pure barium carbonate (BaCo5) and titanium dioxide (TiO), are mixed with pure water in a pot mill for 20 to 30 hours, and after dehydration and drying, the mixture is heated at 1000°C in the air. Calcinate for an hour.

The calcined product thus obtained is wet-pulverized with pure water in a pot mill, dehydrated and dried, and then granulated by adding f-inda and passed through a 32-mesh sieve for granulation.

Next, pb Zr Os is prepared by mixing chemically high-purity PbO and ZrO2 with pure water in a bot mill for 20 to 30 hours, dehydrating and drying, and then calcining in air at 800° C. for 2 hours.

The calcined product obtained in this way was wet-pulverized with pure water in a bot mill, dehydrated and dried, and then added with an inductor.
Sort through a 2-mesh sieve.

Granulated powder of BaTiOs and Pb Zr O@ is used to obtain a laminated molded body l using a mold and a hydraulic press. First, the component j3a TiOs of the preform 1a is molded at a molding pressure of 1 ton/
It is formed into a disk shape with a diameter of 15 io+ and a thickness of 1013 m.

Next, the preform 1b is made of the B granulated as described above.
a Ti O@ and Pb Zr On in a volume ratio of 80:20
After mixing, the mixture is molded at a molding pressure of 1 ton/d.

Hereinafter, in the same manner, the preform 1c has a volume ratio of "Tl
” /Pb Zro, ” ”/h Preformed body 11;
I body ffl ratio te” Tlo, /pb Zr Os −
'/4 b The preformed body 1e has a volume ratio of Pb and Zr.
Molding was performed using only O. at a molding pressure of 1 ton/cIi.

Next, the preforms l&~le obtained by K as described above were stacked in order from the preforms 1e to la and set in a mold, and the molding pressure cuff was 15 m in diameter and 15 m in thickness at 9 tons/cIi. A laminate molded product 1 of No. 40111 is obtained.

Next, the procedure for filling the box will be described. First, a fine powder 18 made of granulated powder of Pb Zr O@ is spread on the bottom surface of the casing 16 made of magnesia so that there are no irregularities on the bottom surface of the casing 16 . A spacer 6b is placed on top of this, and a small amount of fine powder 15 of Pb Zr Os granulated powder is spread.

Next, the laminate molded body 1 and block 10 obtained as described above were set, and Pb, Zr O,
A fine powder 15 made of granulated powder is filled up to the same height as the block 10.

Next, after spacers 6a and 5b are placed on block 10 and fine powder 15, block 9 is placed on spacer 5b, and fine powder 14 is filled in the same manner as above.

Thereafter, spacers 5a and 4b are sequentially formed in the same manner.

It is placed on block 8' and filled with fine powder 13, and finally spacers 3a and 2 are placed on block 7 and fine powder 12.

In this way, the blocks, fine powder, and spacers are stacked one after another, and after the spacers 20 are set, the fine powder 11 is mainly filled in the gap between the laminated molded body 1 and the spacers 2 and 3a,
The laminated molded body is covered with a pot 17 which is magnetically screwed, and finally, the lid 16m of the casing 16 is placed thereon.

Firing is performed at 1200°C to 1300°C for 2 hours to obtain a sintered body. In this case, as the firing temperature increases, the laminated molded body 1
, blocks 7-1O1 spacers 2-6b and fine powder 1
1 to 15 contract at the same time, no voids are created between the laminated molded body l and the spacers 2 to 6b, and the spacers 1 to 15 contract.
Sintered.

Furthermore, since the firing atmosphere around the laminate compact 1 is adjusted to be the same as the PbO concentration gradient of the laminate compact 1, no change in the composition of the ceramic occurs.

Ceramics with desired properties can be obtained.

In addition, in this invention, the composition using BaTiO3 was described, but in addition to BaTiOs, SrTiOs
(strontium titanate) and even Pb(Zr
, Ti)Os (lead zirconate titanate) b CaTi
0. It goes without saying that the present invention can be similarly applied to porcelain compositions such as (calcium titanate).

(Effects of the Invention) As described above in detail, according to the present invention, preforms having a gradient of PbO concentration in the laminated molded products are laminated, and ten spacers having the same composition as each preform are attached. The 1 m-sized compact was fired by adjusting the firing atmosphere to be the same as the PbO concentration gradient of the preform, so that the desired sintered body was obtained without causing any change in the PbO component during firing. be able to.

[Brief explanation of drawings]

Fig. 1 is a rounded schematic diagram illustrating an embodiment of the method for firing a porcelain composition of the present invention, Fig. 2 is a perspective view of a spacer applied to the above embodiment, and Fig. 3 is a diagram applied to the above embodiment. FIGS. 4(a) and 4(b), which are perspective views of the blocks to be produced, respectively illustrate the conventional firing method for porcelain. 1... Laminated molded body, 1&~le... Preformed body, 2
~6b...Spacer, 7-10...Block, 11
~15.18...Fine powder% 16...Magnesia casing, 17...Magnetic pot. Figure 3 4FIA

Claims (1)

[Claims] (a) BaTiO_3-based, CaTiO_3-based or Sr
TiO_3-based composition and PbZrO_3-based, PbTiO_
3-based or Pb(Zr,Ti)O_3-based composition with a varying mixing ratio to give a gradient in PbO concentration, and (b) laminating each of the above laminates in the casing. A block having the same composition as each preform is arranged for each preform, and each preform is surrounded by a block and a spacer, and a fine powder having the same composition as each preform is filled inside, and the uppermost preform is (c) adjusting the firing atmosphere in the crucible to be the same as the PbO concentration gradient of each of the preforms; A method for firing a porcelain composition, comprising: a step of firing a laminated molded body;