JPH01219178A - Clad container - Google Patents

Abstract

PURPOSE:To obtain the clad container for high temp. excellent in wear resistance with a long life by coating an oxide, etc., as the intermediate layer on the surface of a Mo made container and coating the surface layer of the material dispersing oxide, etc., in Pt, Ph, Ir, etc., thereon. CONSTITUTION:Either oxide, nitride, fluoride or carbide or these mixture is coated as an intermediate layer on the inner face or inner and outer faces of the container composed of Mo. The thickness of this intermediate layer is preferably in about 0.1-5mum. The material dispersing either oxide, nitride, fluoride or carbide with either Pt, Rh, or Ir or these alloys as the main component is coated as the surface layer thereon. The thickness of this surface layer is preferably in about 0.1-100mum. The dispersion amt. of oxide, etc., is preferably at about 0.02-10vol.%. These coatings had better perform by sputtering. The clad container which is excellent in wear resistance with a long life and whose coating metal is not dispersed to the Mo main body even if used for long time at high temp. and whose function is not spoiled is thus obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a clad container used at high temperatures.

(Prior art and its problems) Conventionally, a clad container made of Mo or a Mo alloy whose surface is coated with Ir or an Ir alloy has been used in crucibles for melting ores containing high-temperature glass and metal oxides, and trays for vacuum evaporation. It was widely used for boats, etc.

By the way, the above-mentioned clad container has excellent acid resistance, but since it is used at high temperatures, the crystal grains of the Ir or Ir alloy coating become coarse over time, resulting in contamination from other elements entering from the grain boundaries and damage to the coating. The life of the clad container was shortened due to the decrease in mechanical strength.

Furthermore, when used at high temperatures, Ir diffuses into the MO, impairing its functionality.

(Object of the Invention) The present invention has been made to solve the above problems, and has a long life and excellent wear resistance, and furthermore, even when used at high temperatures, the coating metal does not diffuse into the MO of the container body. The object of the present invention is to provide a clad container that is free from corrosion and does not impair its functionality.

(Means for solving the problems) The clad container of the present invention for solving the above problems includes:
An oxide, a nitride, a boride, a carbide, or a mixture thereof is coated as an intermediate layer on the inner or outer surfaces of a container made of Mo, and on top of this, any one of PC, Rh, Ir, or an alloy thereof is coated. The surface layer is coated with a material in which oxide, nitride, boride, or carbide is dispersed.

In the clad container of the present invention, the reason why the inner or outer surfaces of the container made of MO are coated with an oxide, nitride, boride, carbide, or a mixture thereof as an intermediate layer is because the Mo surface layer This is because it is possible to prevent diffusion of any one of PL, Rh, Ir, or an alloy thereof in the layer, and it is preferable to use the same substance as the substance dispersed in the surface layer in order to obtain strong adhesion. . The reason why the intermediate layer is coated with a material containing either PtXRh, Ir, or an alloy thereof as a main component and any one of oxides, nitrides, borides, and carbides dispersed therein is as follows. This is after the coarsening of the crystal grains of PL, Rh, Ir or their alloys at high temperatures is suppressed.

The coating is preferably performed by sputtering. This is because it is difficult to disperse oxides, nitrides, borides, and carbides in PL, Rh, Ir, or their alloys, which are the main components of the surface layer, using ion blating, vacuum deposition, and wet plating. This is because, as mentioned above, a clad container coated with a material made of PL, Rh, Ir, or an alloy of these in which oxides, nitrides, borides, and carbides are dispersed, as a surface layer, is acid-resistant. In addition, oxides, nitrides, borides, or carbides are dispersed in the surface layer, which suppresses the growth of crystal grains at high temperatures. There is no infiltration of contamination by elements or a decrease in the mechanical strength of the surface layer, resulting in a long life. In addition, since the intermediate layer is coated with oxide, nitride, boride, carbide, or a mixture thereof, any of pt, Rh, Ir, or an alloy thereof in the surface layer will not react with Mo in the container body. Since it does not spread, it does not impair functionality.

As an oxide, A! 203, ZrO, Y2O3
is used, and the nitrides include BN, HfN, TaN,
ZrN and TiN are used, and as the boride, TiB
Z, ZrBz, Hf Bx, TaB, Cr B z are used, and the carbides include B, C1TiC, ZrC,
HfC, VC, NbC, and TaC are used.

Pt and Rh of these oxides, nitrides, borides, and carbides
, Ir or an alloy thereof, the dispersion amount is
If it is less than 0.02 volume%, the effect of suppressing the growth of crystal grains at high temperatures is weak (and if it exceeds 10 volume%, oxides, nitrides,
Since borides and carbides react with glass and the like dissolved in the cladding container, the amount thereof is preferably 0.02 to 10% by volume.

If the thickness of the surface layer is less than 0.1 μm, the effect of preventing MO oxidation will be weak, and if it exceeds 100 μm, the ratio of coating time to longer life will increase, so the thickness should be 0.1 μm.
The range of 1 to 100 μm is preferable. Furthermore, if the thickness of the intermediate layer is less than 0.1 μm, it will not be possible to prevent any of Pt, Rh, Ir, or their alloys in the surface layer from diffusing into the MO of the container body, and if the thickness exceeds 5 μm, the long Since the ratio of coating time to longevity increases, its thickness should be reduced to 0.
A range of 1 to 5 μm is preferred.

(Example 1) An example of the clad container of the present invention and a conventional example will be described. The inner surface of a U-shaped Mo crucible with a wall thickness of 5 mm, a height of 100 mm+, and an inner diameter of 80 mm was coated with the intermediate layer materials of Examples 1 to 10 shown in the left column of the table below by sputtering to the respective thicknesses. Then, the surface layer materials of Examples 1 to 10 shown in the left column of the table below were coated thereon by sputtering to the respective thicknesses to obtain clad crucibles.

(The following is a blank space) On the other hand, as a conventional example, a clad crucible was obtained by sputtering Ir to a thickness of 10 μm on the inner surface of the Mo crucible used in the examples.

However, 500 g of alkali zinc borosilicate glass was put into the crund crucibles of Examples 1 to 10 and the clad crucible of the conventional example, and they were used in an Ar gas atmosphere at a temperature of 1500"C for 1 hour. This was repeated 10 times, and the conventional In the clad crucible of Example, the Ir coating was removed by 3 μm from the inner surface, whereas in the clad crucibles of Examples 1 to 10, the surface layer was 0.5 to 1 μm.
It was only shaved down to micrometers.

Next, the bottoms of the clad crucibles of Examples 1 to 10 and the conventional crucible were heated with a heater directly in the atmosphere and held at a temperature of about 1000''C for 20 hours. Although the Ir coating did not lose weight,
The crystal grains of the Ir coating became extremely coarse, reaching a limit state.
After 20 hours, the Ir coating was destroyed and the weight was reduced by 8 g, whereas in the clad crucibles of Examples 1 to 10, no growth of crystals in the surface layer was observed and no weight loss occurred.

Furthermore, in the conventional clad crucible, diffusion of Ir into Mo, which is the container body, was observed after 10 hours, but in the clad crucibles of Examples 1 to 10, Pt in the surface layer into Mo, which is the container body, was observed even after 20 hours. , Rh, and Ir diffusion were not observed at all.
The functionality of the crucible was not impaired.

For these reasons, the clad crucible of the present invention has a significantly longer lifespan as a crucible for dissolving metal oxides than conventional clad crucibles, has excellent wear resistance, and does not lose its functionality even when used at high temperatures for long periods of time. It turns out that there is no.

In the above embodiment, the intermediate layer and the surface layer are coated only on the inner surface of the Mo crucible, but they may be coated on both the inner and outer surfaces.

(Effects of the Invention) As described in detail below, in the clad container of the present invention, coarsening of crystal grains in the surface layer is suppressed, and contamination from other elements enters from the grain boundaries and decreases in mechanical strength of the surface layer. It has a long lifespan because there is no Furthermore, the surface layer does not lose weight even after long-term use, and has excellent wear resistance. Furthermore, even if used for a long time, the metal in the surface layer does not diffuse into the Mo that is the main body of the container, so there is no loss of functionality. Furthermore, if the entire container is completely coated, it will have a long life even in the atmosphere.

Claims (1)

[Claims] An oxide, a nitride, a boride, a carbide, or a mixture thereof is coated as an intermediate layer on the inner or outer surfaces of a container made of Mo, and on top of this, any one of Pt, Rh, Ir, or an alloy thereof is coated. A cladding container characterized in that the surface layer is coated with a material in which the main component is oxide, nitride, boride, or carbide.