KR830000979B1 - Base metal plate materials for directly heated oxide cathode - Google Patents

Abstract

Metal base plate for directly heated oxide cathode comprises Ni alloy containing 10-20 wt.% Mo, 1-8 wt.% W, 0.1-5 wt.% Zr and deoxidising amount of least one of Mg, Si and Al. The alloy is 80.6 wt.% Ni, 15.0 wt.% Mo, 0.4 wr.% Zr and 4.0 wt.% W. The base plate is coated with alkaline earth metal oxide which emits electrons when heated. The cathode is used in receiving tubes, discharge tubes. The base plate has high mechanical strength and high specific electric resistance.

Description

Gas Metal Sheet for Direct Oxide Oxide Cathode

1 is a sectional view showing the principal parts of an example of a conventional direct oxide oxide cathode.

FIG. 2 is a sectional view showing the principal parts of one embodiment of a series oxide cathode using the base metal sheet for a cathode according to the present invention. FIG.

3 is a characteristic diagram showing the amount of electron emission with respect to the operating time of the present invention and the conventional direct oxide oxide cathode.

TECHNICAL FIELD This invention relates to the base metal plate material for a direct oxide oxide cathode. In general, the cathode is used for a receiving tube, a discharge tube, or a cathode ray tube. However, the cathode is generally required to be able to operate quickly and display an image instantaneously. In other words, a short starting time is required. On the other hand, the cathode is one of a heat radiation type and a direct heat type.

The heat dissipation type has a starting time of almost 20 seconds, but the direct heat type is most suitable as a fast moving type because the starting time is extremely short, which is 1 to 2 seconds. FIG. 1 is a sectional view showing a main portion of a conventionally-proposed direct-type oxide cathode, in which FIG. 1 is a gas in which current is generated and heat is generated, and 2 is a terminal thereof. 3 is an alkaline-earth metal oxide layer having electron radiation (electromagnetic radiation), which is deposited on the top of the base 1 to form a direct oxide cathode.

The base 1 needs to have a plate thickness of 100 μm or less, preferably 60 μm or less, in order to increase the electrical resistance as much as possible and to reduce the heat capacity to shorten the starting time. In the heat-type oxide cathode configured as described above, the metal sheet used as the substrate 1 is made to satisfy the requirements such as increasing the high temperature strength and the electrical resistivity and radiating the electromagnetic radiation of the oxide cathode to the maximum. As alloys, alloys with W as 20 to 30 wt% and Zr as 0.3 to 5 Wt% are proposed. However, when the metal sheet material according to the above composition is used as the substrate 1, a large amount of tungstate intermediate layers not shown between the substrate 1 and the oxide layer 3 during the manufacturing process of the CRT and the operation of the cathode are used. And the tungstate intermediate layer has a disadvantage in that the oxide layer 3 is easily peeled off.

It is conceivable to use Mo instead of W to eliminate such defects, but since Mo has lower reactivity with the oxide layer 3 than W, it does not actually produce a molybdate intermediate layer. In this case, when Mo is used instead of W, the oxide layer 3 is less likely to be separated as compared with the case where W is used, and high temperature strength, electrical resistivity, diffusion rate of Zr, etc. are used. Almost equivalent characteristics are obtained in comparison with the above.

However, since the Mo contained in the gas is low in reducing the oxide layer 3, the reactivity to the oxide layer 3 decreases. As a result, when the reducing agent contained in the gas is consumed and the reducing agent is not sufficiently supplied, when the reducing agent containing the electron radioactivity of the oxide cathode is consumed, when the reducing agent is not sufficiently supplied, the electron radioactivity of the oxide negative electrode is prolonged for a long time. A problem arises that cannot be maintained. That is, there is a drawback that the amount of electron radiation of the oxide cathode and its life are greatly reduced. Therefore, an object of the present invention was devised to eliminate the above-mentioned drawbacks, and by including a small amount of W together with Mo, it is difficult to cause peeling of the oxide layer, and moreover, the reducing agent is consumed, and the supply thereof can be sufficiently performed. It is an object of the present invention to provide a base metal plate material for a direct type cathode that can maintain electron radioactivity of an oxide cathode even after it is lost.

In order to achieve the above object, the base metal plate for a direct type negative electrode according to the present invention contains Mo in order to increase the high temperature strength and the electrical resistivity, while reducing the supply of the oxide negative electrode even when the reducing agent is consumed. In order to maintain electron radioactivity, an oxide is contained by pyrolysis of carbonate, and the amount of W is contained so that a large amount of tungstate intermediate layer is not generated in the early stage of the service life. Hereinafter, the base metal plate material for a series negative electrode according to the present invention will be described in detail with reference to the drawings.

FIG. 2 is a sectional view showing main parts of an example of a series oxide cathode using a base metal plate for a cathode according to the present invention, in which the base 4 is Mo in weight ratio by standard powder metallurgy. 15%, w 4%, Zr 0.4%, and the remaining Ni ingots were formed, and vacuum annealing was repeated at this rate, followed by cold rolling. A metal plate member was formed and a direct oxide oxide cathode was constructed using this plate member. In the heat-type oxide cathode constituted as described above, the base material 4 is formed by adding 4 wt% of w to an alloy of 80.6 wt% Ni and 15 wt% Zr to 0.4 wt% of Zr to diffuse high-temperature strength, electrical resistivity, and Zr. As a result of measuring the speed and the like, Ni, which is formed of an alloy of 82.1 wt% Mo and 17.5 wt%, and Zr 0.4 wt%, has almost the same characteristics as the so-called w-free negative electrode. That is, by containing 15 wt% of Mo, the high temperature strength and the electrical resistivity can be selected to a predetermined value. In addition, by adding a small amount of w (4 wt%), three-membered carbonates of Ba, Sr, and Ca were applied to the top of the gas 4, and heated for 10 hours in a vacuum at about 1000 ° C. When decomposed and when energized, no tungstate intermediate layer was formed, so that the oxide layer 3 was not peeled off at all, and Zr (0.4 wt%) as a reducing agent was consumed, so that the supply could not be sufficiently performed. Later, this w reduces the oxide layer 3, so that the electron radioactivity of the oxide cathode can be maintained for a long time.

Next, various experiments were carried out in the above configuration, and the results were as follows. That is, three-membered carbonates of Ba, Sr, and Ca are applied to the government of the above-described gas 4, and are thermally decomposed at 1000 ° C. for about 10 hours in a vacuum atmosphere to form these carbonates as the oxide layer 3. In the middle, the oxide layer 3 was scratched with a pin tip, and the adhesion strength of the oxide layer 3 was examined, that is, no peeling of the oxide layer 3 occurred. In addition, as a result of performing an x-ray diffraction test after removing the oxide layer 3 in the same sample, neither of the physically dated intermediate layer and the tungsten dated intermediate layer was detected. In addition, in FIG. 3, the dependence on the operating time of the electron emission amount in the case where the oxide layer 3 of (Ba, Sr, Ca) O is formed in the government of the base 4 and mounted on the actual color CRT is shown in FIG. Indicated.

In the figure, the characteristic [I] shows the electron emission life of the cathode using the base metal plate (30 μm in thickness) according to the present invention in which Mo is 15 wt%, w is 4 wt%, Zr is 0.4 wt%, and the remainder is made of Ni. , Property [II] shows the electron emission life of the cathode using the conventional base metal plate material in which w was 27.5 wt%, Zr was 0.4 wt%, and the remainder was made of Ni. Therefore, as can be seen from this figure, the direct oxide type cathode using the base metal plate according to the present invention was able to significantly lengthen the electron radiation lifetime. In the above embodiment, the composition ratio has been described with respect to the case where the Mo amount is 15 wt% w, the 4 wt% and the Zr is 0.4 wt, but the present invention is not limited to this composition ratio. If the Mo content is less than 10wt%, the electrical resistivity and the high-temperature strength are not sufficiently secured. If the Mo content exceeds 22wt%, the solid solution limit is exceeded, so Mo precipitates during repeated heating and cooling. Therefore, 10 ~ 22wt% is the optimum amount of the practical range. If the w content is less than 1wt%, it is not enough to maintain the electrospinning of the oxide cathode. If the w content is more than 8wt%, the tungstate intermediate layer is used in the process of obtaining oxide by pyrolysis of carbonate and in the early life of the tube. To prevent w from reacting with the oxide layer thereafter. Therefore, 1 to 8 wt% is an optimal amount. In addition, if the amount of Zr is less than 0.1 wt%, good initial characteristics cannot be obtained. At a value exceeding 5 wt%, a low melting point process (eu: eutectic) is formed and high-temperature strength characteristics are deteriorated. Therefore, 0.1 to 5 wt% is an optimal amount. As described above, the base metal sheet for the direct oxide oxide negative electrode according to the present invention is fired by containing Ni as its main component and containing 10 to 22% Mo by weight, 1 to 8% w by weight, and at least one reducing agent. The formation of the tungstate intermediate layer formed between the gas and the oxide intercalation during the formation or the energization can be prevented, thereby preventing the oxide layer from peeling off and at the same time, sufficient amount to the oxide layer. Since it is possible to supply a reducing agent of, it is possible to enhance the electron emission of the oxide layer over a long period of time, which has an excellent effect such as significantly longer life.

Claims (1)

A base metal sheet for a direct oxide oxide negative electrode whose main component is Ni, wherein the above-described base metal sheet includes Mo in a weight ratio of 10 to 22%, w in a weight ratio of 1 to 8%, and at least one reducing agent. Metal plate for direct oxide oxide cathode.

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