JPS6270041A - Manufacture of compounded 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 Industrial Application] The present invention relates to a method for producing a composite ceramic having a high flexural strength, which is a composite of seven ceramics having a plurality of properties.

[Conventional technology]

Ceramics have superior properties2 to conventional metal materials in terms of heat resistance, high rigidity, wear resistance, and corrosion resistance, and their use as structural materials has begun to be attempted in a wide range of fields. It has become. In general, ceramics are significantly more sensitive to the presence of defects than metals.

Strong resistance to compressive stress? However, it is weak against tensile stress and has a high probability of breaking even with a small force. The degree also varies depending on the ceramic material. For example, A
l2O, breaks at low stress.

Although the thermal shock resistance is inferior, ZrO2゜particularly partially stabilized zirconia (hereinafter abbreviated as PSZ) can be used even under high stress and has high toughness among ceramics, so it has been widely used in recent years. It's starting to look like this. [Problems to be Solved by the Invention] However, zirconia ceramics have the drawback of being extremely expensive. Furthermore, even if the fired PSZ and other inexpensive fired ceramic bodies were to be joined together, the joining would be difficult and would also tend to be costly. Also,
A method of filling the first and second layers of both layers in a molding die during powder pressing and pressing could be considered, but due to the difference in shrinkage rate, they peeled off during firing and could not be bonded.

The present invention was made in view of the above-mentioned problems of the prior art, and combines zirconia ceramics, which have excellent properties but are expensive, and alumina ceramics, which are cheap, to combine the advantages of both. The object of the present invention is to provide a method for manufacturing composite ceramics with sufficient bonding strength.

[Means for solving problems]

Therefore, in the present invention, a firing aid R is added and a zirconia ceramic powder layer is arranged on one side of the forming die, and a firing aid R is added and a zirconia ceramic powder layer is arranged on the other side. The gist of this invention is a method for producing composite ceramics characterized by providing 21 or more mixed layers of alumina-based ceramic powder and zirconia-based ceramic powder between powder layers, press-molding, and then heating and firing.

[Embodiment]

Next is the manufacturing method of the present invention? This will be explained based on FIG.

FIG. 1 is a longitudinal sectional side view showing the state inside the press molding die. The present invention relates to Al2O3゜ZrO2 and 1? Consists of mixed genera. One of these is a mixed layer? Providing this is the most important point of the present invention. Al2O3 and Zr
Each O7 is molded at a pressure of about 400 to 1000 kgf/d.

When molding pressure is constant (molding pressure 600kg shoulder), 155
The shrinkage rate when fired at 0°C is 1. Ad20318%, Z
The rO□ is about 25%. Therefore, as explained in the conventional method above.

In case of double layer pressing on Al 203 and ZrO2,
It peels off from the border and no product is obtained. The mixed layer is.

The purpose is to prevent peeling due to this difference in shrinkage rate.
Is there a difference in shrinkage rate depending on this layer? Absorb.

FIG. 1 shows an example in which the volume ratio of Al2O3:ZrO2 is t1:1, but this is not the case for products, especially thick-walled products.

ratio? In some cases, multi-layer molding is performed, with gradual changes. In addition, Al2O3 is M, yO'i as a sintering aid.
0.5% by weight, ZrO2 is Y20s k 3 mo
It is preferable to add 13% of each. After press molding in this state, preferably xsoO~16
Calcination is carried out in the atmosphere at a temperature of 0.000C. Below 1500'C.

ZrO2 is sufficiently densified, but Al2O3 is hardly sintered. Also, 1600℃? If you cross it.

Although Al2O3 is densified, ZrO2 tends to cause grain growth and the advantages of high strength and high toughness, which are the most important characteristics of ZrO2, tend to be lost.

[First Example] A having an average particle size of 0.5 a m k as a raw material powder
Powder added with l2O3niMJO0.5wt%, and Zr
O2 was prepared by adding 23 mo1% of Y2O3, and on these raw materials, 100 voJ% of Al2O3 system, Al2O3
:ZrO2-based 50: 50 VO1%, ZrO2
The system is molded to 100vo1%, and the molding pressure is 400kgf/7
And so. After that, the molded body is completely dried in the atmosphere: 1550°
Hold at C for 5 hours.

Manufactured by composite ceramics company. The density of the composite ceramic of this example obtained as a result was 4.92 El/cf,
The transverse rupture strength was approximately 50 Yuf/m%.

[Second example] The raw material powder was the same as that used in Example 1.

My○0 in Al2O3 with an average particle size of 0.5μmk
．． 5 W t% added powder and ZrO2 is Y2O3
23mo71! % addition, prepare these raw materials Al2O3 system 100voj%, Al2O3: ZrO
2 series 75:25. 50: 50.25 near 5vo 6%,
It was molded into a multilayer of ZrO2-based 100vo6%. The molding pressure was set at 40 kgf.

Thereafter, it was dried and kept at 1550°C for 5 hours in the atmosphere.

Composite ceramics? Manufactured. The density of the composite ceramic of this example obtained as a result is as follows.

4.98.9/cn (transverse rupture strength is 60 kg f/n+n
Ivy at about t.

〔Effect of the invention〕

Since the composite ceramic produced by the method of the present invention has good bonding between two parts, the advantages of A1203 and ZrO2 can be effectively utilized. Therefore, ZrO
By compensating for the expensive disadvantage of 2 with the inexpensive ceramics of 2Ag, .o3, it can be applied to an extremely wide range of fields.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of a molding situation of a composite ceramic as an example of the present invention. 1... Molding die, 2... Molded body, 2a... Al
2O3 system 100voJ% layer, 2 b ・-a12
o3: ZrO2-based 50: 50 vod% layer,
3 c-ZrO, system 100vo/% layer

Claims (1)

[Claims] An alumina ceramic powder layer to which a firing aid has been added is arranged on one side of the forming die, a zirconia ceramic powder layer to which a firing aid has been added to the other side, and the alumina ceramic powder is placed between the two powder layers. A method for producing composite ceramics, characterized in that a mixed layer of zirconia-based ceramic powder is provided, press-molded, and then heated and fired.