JPH0799309B2 - Ultra high temperature test or treatment method - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a novel ultrahigh temperature test or treatment method.

[0002]

2. Description of the Related Art In recent years, with the remarkable development of aviation or space science and technology, research and development of various materials which can be favorably used in the field have been actively promoted. This kind of material is required to have many functions and to be able to withstand use even in an extreme environment of an extremely high temperature of 2000 ° C. or higher in an oxidizing atmosphere. Therefore, it becomes necessary to easily and accurately measure and test whether or not the newly developed material has sufficient physical properties such as compressive strength and tensile strength under such an ultrahigh temperature. In addition to this, if it is possible to process and weld a material that cannot be easily welded by utilizing such an ultrahigh temperature, it will be very useful because a superior material can be newly developed.

On the other hand, various devices suitable for performing various tests and treatments under high temperature by heating to a high temperature of about 1000 to 2000 ° C. have been developed.
Since there is no apparatus that can be suitably used for the above-mentioned test or treatment in an oxidizing atmosphere, its development has been desired.

For example, Japanese Unexamined Patent Publication No. 2-230085 discloses a primary heating chamber having a high temperature resistance heating element, an ultra high temperature resistance heating element, and a secondary heating chamber installed in the primary heating chamber. Although an electric resistance furnace composed of the following is proposed, it cannot be satisfactorily implemented due to the complicated structure of the apparatus and the reaction occurring during the test or treatment operation.

That is, when a melting test of a sample is performed using such an electric furnace or a general electric furnace, the sample is placed in a crucible, for example, a platinum crucible, and the platinum crucible is melted at a high temperature of 1800 ° C. or higher. I can't test it. If an iridium crucible having a melting point higher than that of platinum (melting point 2454 ° C.) is used, it cannot be used because oxidation occurs in the oxidizing atmosphere. On the other hand, when a refractory crucible such as a zirconial crucible is used, the sample and the crucible react with each other and melt at 1750 ° C. before reaching 2000 ° C. The above is the case of using the crucible, but the same problem as the crucible occurs when the sample is placed on the bed.

[0006] Further, Japanese Patent Application Publication No. 59-500912 discloses an invention relating to an improved zirconia induction furnace, which allows the temperature to be raised to a high temperature by oxidation and can be used for drawing an optical fiber. However, since it is an induction furnace, it suffers from the drawbacks that it is subject to radio interference regulations and the induction transmitter is expensive.

Under these circumstances, the present inventors previously developed an ultrahigh temperature electric resistance furnace and applied for a patent (Japanese Patent Application No.
No. 226183). This uses a hollow cylindrical zirconia resistance heating element having a space penetrating in the vertical direction. According to this, an object to be treated is inserted into the hollow portion of the hollow cylindrical heating element from above or below. Although it is possible to easily heat to an ultrahigh temperature, the inventors of the present invention have used the ultrahigh temperature electric resistance furnace to generate the above-mentioned problems under an ultrahigh temperature and an oxidizing atmosphere, which have been difficult in the past. The present invention has been completed by finding that a test operation such as strength measurement or a processing operation such as welding at such an ultrahigh temperature can be easily performed.

[0008]

Therefore, according to the present invention, a heating portion capable of heating a sample or a material to be treated therein,
A hollow cylindrical zirconia resistance heating element with terminals at both ends is supported upright by a pipe-shaped refractory, and a device for preheating the heating element and a cylindrical refractory for protecting it are provided on the outside thereof. The cylindrical refractory material surrounds the heating element and is provided in the order of zirconia-based cylindrical refractory material and alumina-based cylindrical refractory material, and the alumina-based cylindrical refractory material is used as a device for preheating the heating element. A surface is equipped with a preheater, and the hollow cylindrical resistance heating element and the pipe-shaped refractory material use an ultra-high-temperature electrical resistance furnace having a space that vertically penetrates inside, and a sample or an object to be treated Provided is an ultrahigh temperature test or treatment method, which is characterized in that it is inserted into the space from above and below and heated to an ultrahigh temperature in the heat generating portion to test various physical properties of the sample or to treat the object to be treated. To do.

[0009]

First, an example of an electric resistance furnace which is preferably used in the method of the present invention will be described with reference to FIG. Used. This is provided with a heat generating portion 2 having a thin diameter, that is, a small cross-sectional area in the center portion, and terminal portions 3 having a constant diameter having a larger diameter, that is, a larger cross-sectional area, at both ends thereof. A lead wire 4 for energization such as a platinum wire or a platinum-rhodium alloy wire is attached to the terminal portion 3. Heating part 2
The terminal portion 3 has an inner diameter of a size necessary for putting a sample or an object to be processed in and out and generating heat therein. This heating element will be described in detail later.

In order to support the heating element 1 upright, pipe-shaped refractory materials 5 are provided above and below the heating element 1. The refractory 5 is made of alumina, magnesia, or the like having excellent electric insulation, and the lead wire 4 is embedded therein.
The inner diameter of the refractory 5 is the same as the inner diameter of the heating element 1. When lanthanum chromite, lanthanum manganite, lanthanum cobaltite, or the like is used as the refractory material 5, the energizing lead wire 4 is unnecessary.

On the outside of these, a preheating device for the heating element and a cylindrical refractory are arranged. First, a zirconia-based cylindrical refractory material 6 and an alumina-based cylindrical refractory material 7 are arranged in this order around the heating element 1. In order to reduce the heat load on the refractory material 6 and to prevent leakage of electricity from the heating element 1, the heating element 1
A slight space 8 is provided between the refractory 6 and the refractory 6. The surface of the alumina refractory 7 is provided with a preheat heater 9 for preheating the heating element 1. The alumina refractory 7 prevents the preheating heater 9 from leaking and prevents the preheating heater 9 from being heated when the heating element 1 is at a high temperature. Can be protected from the effects. The preheater 9 is wound around the outer surface of the alumina refractory material. Aluminous mortar is used as the spacer and adhesive.

As the preheating heater 9, a non-metallic heating element such as silicon carbide or molybdenum disilicide, or a metallic heating element such as Fe-Cr-Al system or platinum is used. From the viewpoint of thermal efficiency, it is preferable to use a metal heating element wound around the refractory material 7. At that time, when zirconia is used for the refractory, a leakage phenomenon occurs in the refractory, so that it is necessary to interpose the alumina refractory.

A ceramic heat insulating material 10 and an outer shell 11 are provided outside the alumina refractory 7. As the heat insulating material 10, an alumina-silica fiber block or bulk is applied. Thereby, the iron skin 11 is protected and insulated. Further, when the entire size of the furnace body is restricted, the iron shell 11 can be water-cooled or air-cooled by making the iron shell double structure and flowing water or air inside.

The hollow cylindrical resistance heating element 1 and the pipe-shaped refractory 5 are provided with a space 12 vertically penetrating therethrough to insert a sample or an object to be treated from above or below and the heating portion 2 of the heating element 1 is inserted. It can be arranged in the ultra-high temperature heating space 13 in the vicinity. A means for placing or suspending the sample or the object to be processed can be provided in the space 13, and the upper or lower part of the space can be sealed with a refractory material depending on the purpose (not shown).

The hollow cylindrical resistance heating element and the refractory material arranged around the pipe-shaped refractory material supporting the same should be made of a material capable of withstanding the heat when the heating element reaches a high temperature. It is necessary, and alumina or zirconia-based material is used as described above. A zirconia-based refractory is particularly suitable, and for example, a zirconia hollow sphere, a zirconia powder and a zirconia fiber can be used (Japanese Patent Application No. 2-242244). As the zirconia fiber, a zirconia fiber stabilized by adding a stabilizer such as lime, magnesia or yttria to the pure zirconia fiber is also used. In addition to this, JP-A-3
It is composed of zirconia fiber and zirconia powder as described in JP-A-83856, and has a bulk specific gravity of 2.
It is also possible to use a refractory material having a skin layer of 5 to 5.0 and having a hollow inside or being filled with a filler consisting of fibers of zirconia, hollow spheres, or fiberboard inside. it can.

The method of the present invention is carried out by using such an ultrahigh temperature electric resistance furnace, and the drawings will be described below in order. First, in FIG. 2, a sample A (hereinafter, simply referred to as a sample) is placed on a support base 15 made of a material that does not react with the sample A, and the sample A is downwardly penetrated into the hollow cylindrical resistance heating element 1 in a space 12 extending vertically. And perform a heat treatment test, a firing test and a melting test on the sample by heating it to an ultrahigh temperature in an ultrahigh temperature heating space 13 surrounded by the heat generating portion 2 to heat-treat, fire and melt the sample. You can To form a long sample without placing the sample on the outer support, insert the long sample into the ultra-high temperature heating space 13 and subject the tip of the sample to heat treatment, baking and melting for testing. You can also

For example, when melting an alumina sample, this sample is placed on an alumina support, or a long alumina sample is formed and inserted into the ultra-high temperature heating space 13 for heating and melting, as described above. It is possible to melt the sample without melting the crucible or bed and causing the reaction between the crucible and the bed. If gradual cooling is required after the melting test, or if rapid cooling is required, adjust the temperature of the heating element 1 for gradual cooling, or pull down the sample for rapid cooling, depending on the conditions. Can be adjusted accordingly.

In FIG. 3, the sample A is connected with, for example, a platinum wire or a platinum rhodium wire 16 and hung from above in the space 12, and the sample A is heated in the ultrahigh temperature heating space 13 near the heat generating portion 2. A rapid heating test can be performed by heating to an ultrahigh temperature to a temperature close to the melting point of the material of the metal wire, and further dropping and rapid cooling to perform a rapid cooling test. Further, a calorimeter may be provided immediately below to measure the specific heat. Incidentally, the melting point of platinum is 1755 ° C and the melting point of rhodium is 1966 ° C.

In FIG. 4, the sample A is placed on the tip of the balance 17, which is hung from above and placed in the space 12 to be heated to an extremely high temperature so that the weight change due to the temperature change can be measured. .

In FIG. 5, the sample A is placed between the support base 18 and the holding jig 19 and is inserted into the space 12 to make the sample A.
The compressive strength can be measured, for example, by applying a compressive pressure from above and below in one direction or with a hydraulic device while locating in the ultrahigh temperature heating space 13. Hot pressing can be performed at the same time. For example, when a zirconia refractory is used as a support and as a holding jig, an alumina sample is hot-pressed at a temperature of 2000 ° C. and a pressure of 10 kg / cm ² to obtain a sample having a porosity of 0.

In FIG. 6, the sample A is placed on the supporting bases 20 and 2.
It is possible to measure the tensile strength of the sample by sandwiching this between 1 and putting it in the space 12 and pulling the upper and lower supports in opposite directions by a hydraulic device while heating at an extremely high temperature.

In FIG. 7, for example, two alumina samples A and A'are difficult to weld if they are put into the space 12 from above and below and brought into contact with each other and heated to an ultrahigh temperature of 2050 ° C. in an ultrahigh temperature heating space. Welding of materials can be performed.

In FIG. 8, a long alumina sample A containing impurities such as alkali and 1% iron is added to the space 1.
By putting it in No. 2 and heating it to 2050 ° C. in an ultra-high temperature heating space, the heated portion 22 can be melt-refined to make impurities zero, and thus partial melting or partial refining treatment can be performed. it can.

In FIG. 9, for example, the silica sample A is put into the space 12 and the tip 23 thereof is heated to about 1800 ° C., and the silica fiber 2 is easily drawn downward.
You can make 4. It can be used as an optical fiber.

[0025]

As described above, according to the method of the present invention, by using an ultrahigh-temperature electric resistance furnace having a hollow cylindrical zirconia-based resistance heating element, a sample can be placed in the vertical space formed in the hollow cylindrical heating element. Or, by inserting the object to be processed and heating it to ultra high temperature easily, without causing reaction or melting of the sample or jig, measurement test of various physical properties under ultra high temperature or oxidizing atmosphere, welding, hot pressing, etc. It is effective because it can perform processing. Further, since a zirconia-based cylindrical refractory is provided just outside the heating element of the ultra-high-temperature electric resistance furnace used in the present invention, and further provided on an alumina-based cylindrical refractory outside thereof, an alumina having a melting point of about 2050 ° C. The porous cylindrical refractory does not directly receive the high temperature of the heating element to be semi-molten or to have a large shrinkage. Also, since an alumina refractory material that has better electrical insulation than zirconia is provided outside the zirconia refractory material and a preheater heater is provided on the surface of the alumina refractory material, the thermal efficiency of the preheater heater rises and electric leakage may occur. Absent. Therefore, according to the present invention, it is possible to smoothly and easily carry out a test and a treatment of a sample and an object to be treated at an ultrahigh temperature.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of an ultrahigh temperature electric resistance furnace suitable for use in the present invention.

FIG. 2 is an explanatory diagram showing a state in which a melting test is performed according to the present invention.

FIG. 3 is an explanatory diagram showing a state in which a rapid cooling test is performed according to the present invention.

FIG. 4 is an explanatory diagram showing a state in which a weight change measurement test is performed according to the present invention.

FIG. 5 is an explanatory diagram showing a state in which a compressive strength measurement test is performed according to the present invention.

FIG. 6 is an explanatory diagram showing a state in which a tensile strength measurement test is performed according to the present invention.

FIG. 7 is an explanatory diagram showing a state in which a welding process is performed according to the present invention.

FIG. 8 is an explanatory view showing a state in which partial melting and refining treatment are performed according to the present invention.

FIG. 9 is an explanatory view showing a state in which an inorganic fiber stretching treatment is performed according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hollow cylindrical resistance heating element 2 Heating part 3 Terminal part 12 Vertical penetration space 13 Ultra-high temperature heating space 15 Support stand A Sample

Claims (1)

[Claims] 1. A hollow cylindrical zirconia resistance heating element having a heat generating portion capable of internally heating a sample or a material to be treated and terminal portions at both ends thereof is supported upright by a pipe-shaped refractory, and the outside thereof. the heating element will be provided a cylindrical refractory to apparatus for preheating and protect it to the cylinder
-Shaped refractory surrounds the heating element and is a zirconia cylindrical refractory
And alumina cylindrical refractory in this order.
Alumina cylindrical refractory as a device for preheating a heating element
Is equipped with a preheating heater on the surface of the hollow cylindrical resistance heating element and the pipe-shaped refractory, and an ultra-high temperature electric resistance furnace having a space penetrating in the vertical direction is used inside the sample or the object to be treated. Is inserted into the space from above and below and is heated to an ultrahigh temperature in the heat generating portion to test various physical properties of the sample, or the object to be treated is treated, or an ultrahigh temperature test or treatment method.