JPS61291450A - High alumina 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 "Field of Industrial Application" The present invention relates to a high alumina porcelain composition that has high mechanical strength and thermal shock resistance and can be fired at low temperatures.

``Prior art'' High alumina porcelain, which is widely used as a variety of industrial materials, contains Altos K as the main component, and 5ins, CaO, and MgO as auxiliary components, singly or in combination.
It is formulated as a mixture of more than one species.

"Problems to be Solved by the Invention" Conventional high alumina porcelain compositions containing the above-mentioned subcomponents have a main component A 1 *Os of 90% or more (weight ratio, hereinafter the same) and a subcomponent of 10- In the following cases, the sintering temperature is high (
The temperature was 1500°C or higher, and the thermal shock resistance was also dissatisfied.

"Means for Solving the Problems" The present invention aims to reduce the Al*Os content of the main component to 90 to 9
8 and 5 as a 10 to 2% sub-component added to this.
The proportion of the eight elements i02, CaO, and T i Ox is determined in the quadrilateral area connecting points 1, 2.8, and 4 of the attached eight-component system composition diagram.

The main component A120s is 90% or more by weight in order to satisfy the characteristics of high alumina porcelain, and the higher the upper limit is, the better, but if it exceeds 98%, the sintering temperature will be high, and the thermal shock resistance The mechanical strength also decreases, and when it is less than 90%, the mechanical strength decreases. Subcomponent SiO2+ consisting of the remaining 2 to 10%
As clarified by the following examples, CaO and TlOx should be satisfied within the quadrilateral area connecting points 1, 2.8 and 4 of the 8-component system composition diagram at a firing temperature of 1450°C or less. Mechanical strength with transverse rupture strength of 5000 Kf/aA or more and thermal shock resistance with quenching temperature difference of 220° C. or more were obtained.

"Example" 500 tons of alumina (Kaishi Kagaku, UTM, purity 99.999%) as the main component, and as the final product,
The A1z03 accounts for 90.95 and 98%, and the remaining 10
, 5 and 2% of SiO2 + CaO and Ti0z are shown at points 1, 2° 8 and 4 in the attached 8-component system composition diagram.
Within the scope of the present invention within the quadrilateral area including on the sides connecting the quadrilateral area, and outside the area where the above subcomponents are outside the quadrilateral area, and the main component A I ! Os is set to 88 and 99 chi outside the range,
Silicic anhydride, calcium carbonate, and titanium oxide, which are the remaining subcomponents, are weighed so that the remaining 12 and 1g of the above subcomponents are contained within the rectangular area, and 4001 of water! , along with 10 tons of organic binder hydroxyglobil cellulose (HPC-8L, Nippon Soda), and a polyester with an internal volume of 1.52 and an internal volume of 1.5
Mixing was carried out at 84 RPM for 72 hours using a polyethylene ball mill of No. 1 and an alumina ball with a purity of 99.99%, and the resulting slurry was dried for 5 hours using a freeze dryer. The dried product was passed through a 32 mesh sieve. and granulated.

Each of the granulated raw material powders was molded into a square plate shape of 4.8 x 9.6 x 86 m using a mold press at 1500 II/all, and the molded bodies were heated in an electric furnace at a temperature at which the specific gravity reached its maximum. Samples were prepared by holding and firing for a certain period of time, and the results of measuring the properties of the samples are shown in each figure.

As revealed by Tables 1 to 8, the main component A
I! Os is set at 90% at the lower limit, 95% at approximately the middle, and 98 at the upper limit. 2, and when the blending ratio of the latter eight subcomponents is changed, the blending ratio of the eight subcomponents corresponds to the numbers 1 to 10 in the quadrilateral area of the 8-component system composition diagram. 1a to 10a+1b to 10b and 1c to 10c are
Both are sintered below 1450℃, transverse rupture strength 5000Kt/
-While we achieved the result of quenching resistance temperature difference of 220°C or more, even though the blending ratio of the main component A 1 z Os and the eight subcomponents was within the same range as before, the combination of the eight subcomponents was Each sample i corresponding to numbers 11 to 18 whose ratio is outside the quadrilateral area
Klla~18a, 11b~18b and 11c~
For 18c, the firing temperature exceeds 1450℃, the quenching resistance temperature difference is less than 220℃, or the transverse rupture strength is 5000℃.
K4/al! However, it was not possible to obtain a product that satisfied all eight characteristics at the same time.

Next, Tables 4 and 5 show that the range of A 120s of the main component is 88% outside the lower limit and 99% over the upper limit,
On the other hand, the case where the blending ratio of the subcomponents consisting of S iOz e CaO and TlO2 corresponds to numbers 1 to 10 in the quadrilateral area of the above 8-component system composition diagram is shown, and the blending ratio of the 8 subcomponents is shown in the diagram. Even if the ratio is within the range of the present invention, if the content and blending ratio of the main component A 1 z Os is outside the range, one of the firing temperature, quenching resistance temperature difference, and transverse rupture strength It has been revealed that this will cause more dissatisfaction.

"Effects of the Invention" Tables 1 to 8 show that the present invention enables low-temperature firing of high alumina porcelain compositions that have higher mechanical strength and thermal shock strength than conventional high alumina porcelain compositions. Since it reduces the manufacturing cost, it has excellent effects when used in electrical insulating materials such as IC packages as well as various mechanical device parts that require mass production.

[Brief explanation of the drawing]

The drawing shows 5to used in the high alumina porcelain composition of the present invention.
FIG. 2 is a composition diagram of an 8-component system consisting of 2-CaO-TiCh.

Claims (1)

[Claims] Based on 90 to 98% by weight of the main component Al_2O_3,
Subcomponent 10 consisting of SiO_2-CaO-TiO_2
2% by weight is located within the quadrilateral area connecting each point 1, 2, 3, and 4 of the attached three-component system composition diagram ▲ Contains mathematical formulas, chemical formulas, tables, etc. ▼ (Unit: weight fraction)
An alumina porcelain composition characterized in that it is fired at a temperature of 450°C or lower.