JPS597791B2 - heat radiant material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to heat radiating materials, and particularly aims to further improve heat radiation by forming a highly adhesive black oxide film on the surface of a manganese-containing alloy.

Various internal parts of electron tubes are generally made of metal materials. Examples of products that meet the heat radiation requirements for these products include aluminum-coated iron and nickel soot materials. These materials have a blackened surface.For example, aluminum clad iron has a blackened surface by reacting iron and aluminum, and nickel sooting material has a blackened surface due to the reaction between iron and aluminum, and nickel sooting material has a blackened surface caused by burning organic matter and attaches the soot to the nickel. The surface is blackened. In order to improve heat radiation, in addition to increasing the degree of blackening as described above, methods are also used to increase the surface area. It's getting older. However, aluminum clad iron cannot be used at high temperatures, and sooting materials are laborious to work with and often fall off from the base metal due to rubbing. Even if we applied the method of making it a surface, there was a drawback that it was difficult to obtain the desired heat radiation. The present invention has been made in consideration of these points, and aims to eliminate the above-mentioned drawbacks and provide a new material with good heat radiation.

In other words, it is a thermal radiation material in which a manganese-containing alloy is oxidized at high temperature to form an oxide film with a high degree of blackening on its surface. The oxide film formed on the surface by high-temperature oxidation has a good degree of blackening, can withstand high-temperature use, and of course does not peel off. For example, when the material of this invention is treated in the atmosphere at a high temperature of 800°C, an oxide film is formed on the surface of the alloy, and the degree of blackening is 2 (according to JIS Z8721), which is the ideal value. It has a color close to black.

Since the degree of blackening and thermal radiation are almost proportional, products using this material have extremely good thermal radiation, making it a much superior thermal radiation material compared to conventional materials. In other words, a manganese-containing alloy is oxidized in an oxidizing atmosphere such as the air or wet hydrogen, and an oxide film containing manganese is produced. do.

Regarding the degree of blackening, the black oxide film formed on the surface of the heat radiating material of the present invention must contain manganese, and it is desirable that the metal content of the oxide film is 10% by weight or more of manganese. If the manganese content in the oxide film is less than 10% by weight, the film will appear gray, making it difficult to obtain the desired degree of blackening. The heat radiating material of the present invention has characteristics on its surface, and it is also preferable to use the material with its surface roughened. Examples of the present invention will be described below.

A manganese-containing alloy is melted to have the alloy composition shown in Table 1 below. When the alloy in Table 1 above is oxidized at 1σ00℃ in a wet hydrogen atmosphere, or in the air,
The degree of blackening when oxidized at 00°C is shown in Table 2 below.

In this case, the degree of blackening is indicated by lightness (according to JIS Z-8721). As can be seen from Table 2 above, the thermal radiation material of the present invention has an excellent degree of blackening.
When an alloy containing copper, nickel, etc. alone or in combination with manganese is oxidized at high temperatures, a desirable black oxide film is formed on its surface, making it an extremely superior heat radiating material compared to conventional materials.

A thermal radiation material capable of forming such a good black oxide film must have a manganese content of 20% by weight or more; if it is less than this, it is difficult to obtain the desired material. As a result of examining the oxide film formed on the above heat radiating material, it was found that the oxide film with an excellent degree of blackening had a manganese content of 10% by weight or more based on the metal content of the oxide film. It is difficult to obtain the desired degree of blackening of the oxide film, which depends on the amount of manganese contained in the oxide film, if it is less than 10% by weight. The amount of manganese in the oxide film shown in Table 2 is shown in Table 3 below.
Shown below. In this way, the material of this invention can generate an oxide film with a significantly improved degree of blackening on its surface, so it can be used in various applications such as internal parts of electron tubes and water heater parts that require good heat radiation. It is used in many applications and greatly contributes to improving their properties.

Materials with good heat radiation also have excellent heat absorption, so
Therefore, the range of application can be expanded to fields related to heat absorption, such as members used in solar heat absorption devices, and it can contribute to improving the characteristics of those devices.

Claims (1)

[Scope of Claims] 1. A thermal radiation material made of a manganese-containing alloy containing 20% by weight or more of manganese, which is oxidized at a high temperature to form a black oxide film containing manganese on the surface. 2 Manganese is 10% by weight in the metal content of the black oxide film
The heat radiating material according to claim 1, which is the above.