JPS61141682A - Ceramic foam and manufacture - 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] I This invention provides a three-dimensional mesh that can be used for filters used to remove (filter) inclusions (slag) in molten metal, surface heating elements for combustion burners, etc. The present invention relates to a ceramic foam having a structure and a method for manufacturing the same.

[1 animal 1] Ceramic foam filters are used to remove inclusions from molten metal.

Conventionally, ceramic foam used as this type of filter has a porosity of 75 to 95%, a bulk specific gravity of 0.2 to 0.3,
The skeleton has an apparent porosity of 10 to 20% and is made of cordierite, alumina, silicon carbide, etc.

Conventional ceramic foam, in which ceramic is simply adhered and solidified using a soft urethane foam with a three-dimensional network structure as a base material, has a compressive strength of 10 to 30 K.
GF 701112 or less, bending strength is 5! 1lf10
112 or less. Such low strength results in ceramic foams breaking during handling before and during use. This damage is caused by breakage of the skeleton, which has a three-dimensional network structure.

Column 11 11 This invention was made in order to solve the above-mentioned problems, and provides a high-strength ceramic foam that increases the strength of the ceramic foam and is difficult to break when handled before and during use, and a method for manufacturing the same. is intended to provide.

81 days and 1- Therefore, in order to achieve this object, the gist of the first invention is to provide a ceramic foam having a three-dimensional network structure with a bulk specific gravity of 0.4 to 2.0 and a skeleton of The ceramic foam is characterized by an apparent porosity of 5% or less.

Further, the gist of the second invention is to repeatedly apply a ceramic molding slip to a base material form having a three-dimensional network structure and dry and solidify it multiple times.
A method for manufacturing ceramic foam, which is characterized by forming a thick skeleton and firing it to make it into porcelain.

As shown in the figure, the ceramic foam according to the present invention uses a soft urethane foam 1 as a base material foam having a three-dimensional structure, and a ceramic molding slip is attached to the skeleton of the foam to form a first layer. 2. The second layer 3 and the third layer 4 are sequentially molded and dried and solidified repeatedly to form a thick skeleton 5.

The bulk specific gravity of the ceramic foam is 0.4 to 2.0.

Preferably, the skeleton 5 is formed by, for example, the following manufacturing method.

A ceramic molding slip is attached to the skeleton part 1 of the base form having a three-dimensional network structure, and the first 112
After drying and solidifying, second and third layers 3.4 are sequentially formed thereon and dried and solidified in the same manner. In this way, the skeleton 5 is formed to be thick, and then fired at a high temperature of 1700° C. or higher to burn off the skeleton portion 1 of the base material form.

By only slightly changing the bulk specific gravity of the ceramic foam, the strength of the ceramic foam is significantly increased and breakage of the skeleton 5 is reduced. Moreover, the porosity hardly needs to be changed.

Figure 1 shows an example of the method for manufacturing a ceramic foam according to the present invention and the skeleton structure of the ceramic foam.

As shown in the table (see below), Example 1 is a ceramic foam with a chemical composition of 98% by weight A 920 s.

The manufacturing method and basic structure will be explained with reference to FIG.

As the base material foam having a three-dimensional network structure, a soft urethane foam is most suitable.

In the illustrated example, a ceramic molding slip is attached to the skeleton part 1 multiple times (three times) and dried and solidified each time, so that the first layer 12, the second layer 3, and the third layer 4 become thicker. form 5.

A ceramic molding slip is made as follows.

First, a ceramic raw material made of 98% by weight A 11203 is blended to have a particle size distribution of 10μ to 0.1μ and an average particle size of 5μ to 0.5μ.

Ceramic raw materials blended by adjusting particle size and blending ratio as described above, water, quick-drying binder (e.g. PVA) and balls (e.g. ceramic balls)
A slip for ceramic molding is made by mixing in a ball mill and adjusting the viscosity to 2 to 15 poise.

The manufacturing process of the illustrated ceramic foam skeleton 5 will be explained in order. A ceramic molding slip is attached to the soft urethane foam skeleton 1 to form the first layer 2. As shown in FIG. At this time, remove excess slip to prevent clogging of the voids (not shown) in the soft urethane foam, and
Dry and solidify at ~100°C.

Next, an identical ceramic molding slip is applied around the first layer 2 to form the second layer 3. At this time as well, excess slip is removed so as not to clog the voids, and the material is dried and solidified in the same manner as in the first step 112.

Furthermore, the same ceramic molding slip is applied to the second layer 3 to form the third layer 4.

At this time, excess slip is removed and dried to solidify so as not to clog the voids.

In this way, the ceramic molding slip is adhered to the skeleton part 1 of the soft urethane foam until the bulk specific gravity of the product becomes 0.4 to 2°0, preferably 2 to 3 times, and solidified. Shape the skeleton 5 thickly.

Next, the skeleton 5 is fired at a high temperature of 1700° C. or higher to form porcelain. At the same time, as shown in the figure, the skeleton portion 1 of the soft urethane foam is carbonized and removed (burned off), and a space 6 is formed in the skeleton 5.

In Example 1, the chemical composition was 98% by weight A9203, and its properties are shown in the table.

As can be seen from the table, the bulk specific gravity was set between 0.4 and 2.0, and the strength of the ceramic foam at that time, that is, the compressive strength and bending strength, were as shown in the table. That is, the compressive strength is 50 to 100 Kof/Cm2, which is significantly increased compared to the conventional 10 to 30 Kof/am. In addition, the bending strength is 10 to 35) (Of/
cm2, which is also significantly increased compared to the conventional 5 kgf/C112 or less.

However, the porosity in this case is 85 to 90%,
There is only a small change compared to the previous value.

The apparent porosity of the sintered body is 5% or less.

Support m In Example 1, the same ceramic molding slip was applied to the soft urethane foam 1 from the first layer 2 to the third layer! ! ! 4
In Example 2, a separate ceramic molding slip is applied to each layer.

That is, in Example 2, the same 9 was used as the ceramic raw material.
8 wt% A 9z Os was used, the first layer 112 used the ceramic molding slip used in Example 1, and the second layer 113 and third layer 4 were prepared by blending other particle sizes. A ceramic molding slip is used.

To explain in detail, the first layer 2 has a particle size of 10μ to 0.1
It is formed by adhering to a substrate foam a ceramic molding slip prepared from a ceramic raw material having a particle size distribution of 5 to 0.5 microns. After removing excess slip, the first layer 2 is dried and solidified. Its skeleton porosity is 0%.

Next, the second layer 3 has a particle size of 10 μ to 0.1 μ and 70 to 70 μm.
It is formed by adhering to the surface of the first layer 2 a slip for ceramic molding prepared with a ceramic raw material containing 90% by weight and 10 to 30% by weight of particles having a particle size of 44 μm to 10 μm. After removing excess slip, the second layer 3 is dried and solidified. Its skeleton porosity will be 5-15%.

Furthermore, the third layer 4 has 5 grains of 110μ to 0.1μ.
0-70% by weight, particle size 44μ-10μ is 30-5
The second layer 3 is molded by attaching a slip for ceramic molding prepared with a ceramic raw material containing 0% by weight to the surface of the second layer 3. After removing excess slip,
Dry and solidify the third 114. Its skeleton porosity is 15
~25%.

The ceramic foam having the skeleton 5 of the multilayer structure thus formed is fired in the same manner as in Example 1.

The bulk specific gravity is set to 0.4 to 2.0, and other characteristic items such as compressive strength and bending strength are substantially the same as in Example 1.

In the case of Example 2, a large number of pores with a pore diameter of 50 μm to 1 μm exist on the surface of the skeleton 5, so that the removal (filtration) efficiency of inclusions in the molten metal can be increased.

In addition, activated A9203 (γ-Abo3) in the third layer 4
By supporting a PT catalyst or a PT catalyst, a ceramic foam having a catalytic function can be obtained. In that case, the pores in this surface layer cause activation A+! 203, etc., and its durability is improved.

111 In Example 3, unlike Example 1.2, the chemical composition of the ceramic foam is A(!203-7rO2). In this case as well, the same manufacturing method as in Example 1 or 2 is used to make the outline thicker.

The bulk specific gravity of the ceramic foam of Example 3 is the same as that of Example 1.
．． Similarly to Example 2, the compressive strength and bending strength are set to 0.4 to 2.0, and the compressive strength and bending strength have values equivalent to those of Example 1. Moreover, the porosity and pore diameter are also the same as those of Example 1.

Support U The invention is not limited to the embodiments described above.

For example, a slip for ceramic molding has a bulk specific gravity of 0.
If it is in the range of 4 to 2.0, the first layer, the second layer,
The layer is not limited to the third layer, and may include, for example, the first layer and the second layer, or a fourth layer or more may be formed as necessary. In addition, the ceramic raw materials contained in the slip include st c, st3 Na, A(!zoa -8
Materials such as i02 series, cordierite, and z'02 may also be used.

Note that if the bulk specific gravity of the ceramic foam is greater than 2.0, the porosity will be too low, making it difficult for molten metal to pass through the voids, making it difficult to function as a filter.

As is clear from the above explanation, the ceramic foam of the present invention has a bulk specific gravity of 0.4 to 2.0 and an apparent porosity of 5% or less, which is superior to conventional ceramic foams. Although the bulk specific gravity is only slightly changed compared to , the strength can be significantly increased in both compressive strength and bending strength. Furthermore, since the porosity hardly needs to be changed, there is no support for the passage of molten metal, which is extremely effective in practical terms.

Further, according to the manufacturing method of the present invention, it is possible to manufacture a ceramic foam that has high strength and is difficult to break.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing an example of the method for manufacturing a ceramic foam of the present invention and its basic structure. 1... Skeleton of soft urethane foam 2... First layer 3... Second layer 4... Third layer 5... Skeleton of ceramic foam 6... Space Diagram 1 Procedure amendment (Voluntary) March 6, 1985 Director General Te Manabu Shiga Tonoichi Case Indication Patent Application No. 59-260898 2 Name of the invention 2 Ramitsuku foam and its manufacturing method 1 Relationship with the person making the correction 1 Patent applicant 1 location Nishi-Shinjuku, Shinjuku-ku, Tokyo Name Toshiba Ceramics Corporation (1 location 5 Toranomon Electric Building, 2-8-1 Toranomon, Minato-ku, Tokyo) No date of amendment order 6, "Invention" in the specification subject to amendment Column 7 of "Detailed explanation of the amendment" as shown in the attachment 1) r1700J on page 5, line 5 of the specification rl 50
Correct to 0J. 2) rl 700J on page 18, line 10 of the same page 5
Correct to 00J. 3) First, correct "CII" in the 5th line of page 9 of the same book to "Cl12". 4) Add your second daughter between the 2nd and 3rd lines on page 1113. [However, it is superior to Example 1 in terms of thermal shock resistance. 5) In the first line of the table on page 15 of the same book, "Example 2" is [
Corrected with Example 3J. 6) Correct "Void diameter" in the 7th line of the table on the same page to "Void diameter".

Claims (2)

[Claims] (1) A ceramic foam having a three-dimensional network structure, characterized in that the bulk specific gravity is 0.4 to 2.0 and the apparent porosity of the skeleton is 5% or less. (2) A ceramic molding slip is attached to the base foam, which has a three-dimensional network structure, and dried and solidified several times to form a thick skeleton, which is then fired and turned into porcelain. A method for producing characteristic ceramic foam.