JPS59230231A - Anode member - Google Patents

Abstract

PURPOSE:To improve productivity while improving the tubular properties of an electron tube by using a specific amount of Cr, namely, a metal component of the oxide film formed by adding one of Ti, Nb, V and Zr respectively to an alloy of iron and Cr, an alloy of iron, Ni and Cr or an alloy of Ni and Cr. CONSTITUTION:An anode member is formed of a substance made by adding one of Ti, Nb, V and Zr respectively to an alloy of iron and Cr, and alloy of iron, Ni and Cr or an alloy of Ni and Cr, while generating a black oxide film having good stickiness mainly composed of Cr through the high temperature oxidation, for making the anode member used for an electron tube having extremely good thermal radiation. In the metal component of said oxide film, the content of Cr is made not to be less than 35wt%. Thereby, the tubular properties of the electron tube can be remarkably improved, while improving productivity as well as working efficiency.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an anode member with good heat radiation, and an anode made of this anode member is installed in an electron tube to significantly improve the characteristics.

The anodes used in electron tubes, such as transmitting tubes and receiving tubes, are subject to various thermal, electrical, and mechanical requirements. During operation, thermionic electrons emitted from the cathode collide, and the energy turns into heat and is transferred to the anode. Increase temperature. If this temperature exceeds the limit, various problems will occur as follows. In other words, the temperature rise becomes severe and heat dissipation from the anode becomes difficult, the amount of gas released from the anode increases, the temperature of the tube wall of the electron tube rises, and the gas released from the tube wall also increases.
This can cause problems such as thermal deformation, deterioration of characteristics, and the occurrence of accidents. Therefore, it is desirable to improve the thermal radiation of the anode and increase its surface area in order to maintain the temperature at which the electron tube can operate. For this reason, the surface of the iron, nickel, etc. that forms the anode is blackened to improve its emissivity, the surface is roughened, and heat dissipation blades are attached to increase the surface size.

To further explain these measures, the anode with a blackened surface uses a so-called soot material, in which soot generated by burning benzene or the like is deposited on the surface of an anode member made of nickel, iron, iron-nickel alloy, etc. .

In this case, the degree of blackening of the surface is evaluated according to JIS Z-872 and has a brightness of 2 to 3, which is an extremely good degree of blackening. Thermal radiation depends on the surface condition, but it is almost proportional to the degree of blackening of the surface, so - Although it is sufficient for improving thermal radiation as an anode member, it has weak soot adhesion, and
There are disadvantages such as poor suiting workability and poor working environment.

In addition, for small electron tubes that generate a small amount of heat, iron clad with aluminum is used as the anode material. In this case, aluminum is diffused into the iron to form a black intermetallic compound on the surface. It is something that generates. Regarding the degree of blackening of such an anode surface, the lightness level is 2.
-3, but it has drawbacks such as not being able to be used by attaching it to a large electron tube. As described above, the characteristics of conventional anode members are still insufficient, and there has been a demand for an excellent anode member that does not suffer from the above-mentioned drawbacks.

The present invention was conceived in consideration of these points, and is an anode that maintains a sufficiently good degree of blackening on its surface, is economical to be installed in various types of electron tubes, and has two characteristics that improve electron tube characteristics. The present invention provides an anode member that can contribute. In other words, the anode member is formed from a chromium alloy, iron-nickel-chromium alloy, or nickel-chromium alloy to which at least one of titanium, niobium, vanadium, and zirconium is added, and is oxidized at high temperature to form an adhesive layer mainly composed of chromium on the surface. By producing a black oxide film with good properties, an anode member for an electron tube with extremely good heat radiation can be obtained. The black oxide film of the anode member of the present invention is mainly composed of chromium, and chromium accounts for 35% of the metal content of the oxide film.
(wt%, the same applies hereinafter).

Examples of the present invention will be described below. An alloy is melted to have the composition shown in Table 1 below and subjected to conventional processing to form a predetermined shape.

(The following is a blank space) 3-4- The samples (1 to 12) formed as described above are oxidized by heating at 1200° C. for about 1 hour in wet hydrogen with a dew point of 30° C. to selectively oxidize chromium. At this time, almost the same results were obtained even when oxidized in the air.

The surface condition after selective oxidation is shown in Table 2 below.

Table 2: Brightness was evaluated using J-Tech 5z-8721.As can be seen from this table, the blackness of the products of the present invention, in which at least one element such as titanium was added, was significantly lower than the ideal black due to its addition. Due to the close proximity, the heat radiation is also very good. In addition, during work or operation, even if subjected to external forces such as being rubbed, the oxide film will not fall off from the base metal of the anode member, showing strong adhesion, and is superior to conventional sooting materials. The adhesion to the metal has been significantly improved.

The results of examining the chromium content of the oxide film formed on the anode member of the present invention are shown in Table 3 below.

Table 3 As shown in this table, an oxide film that is mainly composed of chromium and has a high degree of blackening contains a large amount of chromium, and the content of chromium in the oxide film changes depending on the oxidation method. However, the examples show very good examples. By changing the oxidizing atmosphere and looking at the relationship between the content of chromium and the degree of blackening, good blackening can be obtained when the chromium content is 35% or more;
If it is less than 35%, the gray color becomes strong, so it is necessary that the chromium content in the metal content of the oxide film is 35% or more.

When the tube characteristics of an electron tube, such as a transmitting tube, incorporating an anode made of the anode member of the present invention were investigated, much better results were obtained than those using conventional sooting materials. Furthermore, since the anode member of the present invention has a firmly adhered oxide film, it is easy to handle when assembling the tube, and the work efficiency is improved, making it extremely useful industrially.

If the proportion of chromium contained in the alloy such as the iron-chromium alloy of the present invention is less than 2%, the effect of improving the degree of blackening will be small;
If it exceeds 5%, the problem of σ phase will occur, so 2 to 35%
A range of is appropriate. Furthermore, if the amount of titanium added to the 7-alloy is less than 0.03%, there is no effect of improving the degree of blackening, and if it exceeds 5%, workability deteriorates, which is a problem. Therefore 0.03～
A range of 5% is preferred.

Alternatively, the anode member may be made of a base metal other than the chromium-containing alloy, the surface of which is coated with the chromium-containing alloy by means such as plating, and then oxidized at high temperature.

As described above, the anode member of the present invention has an extremely good thermal emissivity, which is necessary for an anode used in an electron tube, and a high thermal conductivity.
It has high electrical conductivity, good workability, is an economical material that is easily available, and can form an anode as desired, dramatically improving the tube characteristics of an electron tube equipped with this anode. Moreover, productivity can be increased, making it extremely useful industrially.

Agent Patent Attorney Inoue - Male 8-

Claims (2)

[Claims] (1) It has a black oxide film mainly composed of chromium on its surface, and is made of an iron-chromium alloy, an iron-nickel-chromium alloy, or a nickel-chromium alloy to which at least one of titanium, niobium, vanadium, and zirconium is added; An anode member characterized in that chromium is 35% by weight or more in terms of metal content. (2) The anode member according to claim 1, wherein 0.03 to 5% by weight of at least one of titanium, niobium, vanadium, and zirconium is added.