JPH0582464B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a method for producing an amorphous alloy having a high crystallization temperature. (Prior Art) In recent years, various amorphous materials have been developed and are attracting a lot of attention in the field of metal materials. Unlike conventional crystalline alloys, these alloys do not have a crystalline structure, and many of their properties are not found in conventional metal materials, such as mechanical properties, wear resistance, corrosion resistance, and soft magnetism. Due to its excellent electrical properties, various uses are being developed as a material that can replace crystalline metals, and materials suitable for these uses are also being developed. These alloys have conventionally been generally produced by a liquid quenching method such as a single roll method. (Problems to be Solved by the Invention) The biggest problem with amorphous alloys is that they are thermally unstable. This is due to the fact that the amorphous state is a thermodynamically non-equilibrium metastable state, and can be said to be the fate of amorphous alloys. In other words, each amorphous alloy generally has its own specific crystallization temperature, and when that temperature is exceeded, it changes to a more thermally stable crystalline alloy, and the superiority seen in the amorphous state is lost. All the characteristics that were previously acquired are lost. This crystallization temperature varies depending on the material, but is generally 0.4 to 0.4 of the melting point measured in absolute temperature.
It is known that the value is about 0.6 times. Therefore, in order to obtain an alloy with a high crystallization temperature, an alloy with a high melting point must be made amorphous. Ta-Si alloy has an extremely high melting point of approximately 2300°C or higher. For this reason, it was made using the liquid quenching method.
Ta-Si amorphous alloy has a crystallization temperature of 800℃
The temperature was extremely high at ~960°C, making it possible to significantly improve the problems of amorphous alloys (Patent application 1986-
No. 012385). Furthermore, this Ta-Si-based amorphous alloy has excellent mechanical properties such as high strength and high hardness that are characteristic of general amorphous alloys, so it can be used as a wear-resistant material and , and applications such as electrode materials that involve temperature rises are possible. However, it is produced by liquid quenching method.
Ta-Si amorphous alloys have shapes ranging from several mm to several mm wide.
There was a problem in that it was impossible to obtain an amorphous alloy with a wide area because of the ribbon shape. Furthermore, it has not been possible to form the amorphous alloy in the form of a thin film on a certain substance using the conventional liquid quenching method. The present invention solves the problems of the prior art and provides a method for producing a Ta-based amorphous alloy thin film that has a high crystallization temperature and has excellent mechanical properties, corrosion resistance, etc. With the goal. (Means for solving the problem) The present invention is expressed by the formula Ta _1-x Si _x , where x=0.1
~0.4 by heating and melting the metal in vacuum and vaporizing the metal atoms.
This is a method for producing a Ta-based eutectic alloy thin film, which is characterized by depositing it on a substrate to form an amorphous thin film. (Function) In Ta-Si alloys, as shown in the examples later,
The present inventors have discovered that an amorphous alloy can be formed in a composition range in which Ta is 60 at% to 90 at%. When the composition is outside this range, almost no amorphous structure is observed, and all the excellent properties characteristic of amorphous alloys are lost. The crystallization temperatures of these amorphous alloys vary depending on their high melting points.
This is a high value of over 800℃. In addition, the mechanical properties of these amorphous alloys are high strength and high hardness, as is generally seen in amorphous alloys. Also, in terms of corrosion resistance, it has corrosion resistance comparable to that of Ta. The manufacturing method according to the present invention is a method in which a metal is heated and melted in a vacuum to evaporate metal atoms, thereby depositing them on a substrate to form an amorphous thin film. Since the alloy is melted in a water-cooled crucible, there is almost no reaction between the raw material alloy and the crucible metal. This is because if the crucible metal is sufficiently cooled, even if high-temperature molten metal comes into contact with it, the temperature of the crucible metal is too low and alloying reactions are extremely unlikely to occur. Further, the substrate needs to be cooled with a coolant such as water or liquid nitrogen. This is because if the substrate temperature during thin film production is too high, the formed alloy thin film will become crystalline and an amorphous phase will not be obtained. Furthermore, as melting means, electron beam melting,
Well known methods such as laser beam melting can be used. Further, as the raw material to be melted, a Ta-Si alloy having a desired composition or Ta and Si can be prepared separately. In the case of Ta-Si alloy, by melting this alloy, Ta and Si
If they are prepared separately, a thin film can be formed by separately dissolving each at the same time. In addition, the composition of the obtained alloy thin film can be easily changed by changing the composition of the Ta-Si alloy used as the raw material and by adjusting the vapor pressure of Ta and Si. It is possible to easily obtain an amorphous alloy thin film having the following composition. As described above, by the manufacturing method of the present invention,
A Ta-based amorphous alloy can be uniformly formed over a large area as a high-purity alloy thin film with controlled composition on a substrate. (Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings. FIG. 1 shows an example of an apparatus for producing the Ta-based amorphous alloy thin film of the present invention. The apparatus shown in FIG. 1 is a high vacuum electron beam evaporation apparatus. Evaporated materials 1 and 2 are held in crucibles 3 and 4, respectively. In this example, the evaporation material 1 includes Ta,
Moreover, Si was used as the evaporation material 2. 50g of each evaporated material can be prepared in a crucible. The crucibles 3 and 4 are made of copper and are water-cooled by a cooling water introduction pipe 5, so that the temperature does not rise even when the evaporation material is dissolved. The substrate 6 is fixed to a substrate holder 7.
The substrate used was glass with a length of 50 mm, width of 25 mm, and thickness of 0.2 mm. The substrate holder 7 stores liquid nitrogen 9 introduced from a liquid nitrogen introduction pipe 8, and has a structure in which the substrate is sufficiently cooled. When producing a thin film, first, the vacuum chamber 10 is evacuated to a vacuum level of 10 ^-8 Torr using the vacuum pump 11 . In this state, electron beam source 1
2 and 13, electron beams are generated to simultaneously heat and melt the evaporation materials 1 and 2. Ta and Si evaporate in atomic form from the melted material. During the first hour of vapor deposition, preliminary vapor deposition is performed with the shutter 14 closed. Next, after the preliminary vapor deposition was completed, the shutter was opened to form a thin film on the substrate. The evaporated atoms ejected from the evaporation materials 1 and 2 are mixed with each other near the substrate, and when they adhere to the substrate, they adhere as a homogeneous alloy.
The degree of vacuum during thin film production was on the order of 10 ^-7 Torr.
In addition, when the substrate temperature during thin film fabrication was measured with the thermometer 16 through the thermocouple 15, it was found to be -180°C.
It was hot. The deposition took place for 1 hour. The thickness of the obtained thin film was about 5 μm. The structure of the obtained Ta-Si alloy thin film was evaluated by X-ray diffraction method. As a result, Ta
In the composition range of 60 at% to 90 at%, no sharp diffraction peaks due to crystals were observed in any of the ribbons, and a broad halo pattern was obtained, confirming that an amorphous alloy thin film was obtained. . In Table 1,
The crystallization temperatures of these samples measured by differential thermal analysis are shown. All exhibit high crystallization temperatures of 800°C or higher. In addition, the mechanical properties of these samples showed excellent properties with a Vickers hardness ranging from 800 to 1500. Furthermore, even when these samples were left in concentrated hydrochloric acid, concentrated nitric acid, concentrated sulfuric acid, and concentrated aqua regia for one day, no signs of corrosion were observed, and no change in weight was observed.

【table】

[Table] In this example, a method for producing a Ta-based amorphous alloy thin film using a high-vacuum electron beam evaporation apparatus was introduced. However, when producing an amorphous thin film, other evaporation methods, such as laser It is also possible to use a beam evaporation method, a cluster ion beam evaporation method, or the like. (Effects of the Invention) As explained in detail above, Ta according to the present invention
The method for producing an amorphous alloy thin film has a high crystallization temperature, and can easily produce an amorphous alloy thin film with excellent mechanical properties, corrosion resistance, etc., and is highly effective.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of an apparatus for producing a Ta-based amorphous alloy thin film of the present invention. In the figure,
1 and 2 are evaporation materials, 3 and 4 are crucibles, 5
is a cooling water introduction pipe, 6 is a board, 7 is a board holder,
8 is a liquid nitrogen introduction tube, 9 is liquid nitrogen, 10 is a chamber, 11 is a vacuum pump, 12 and 13 are electron beam sources, 14 is a shutter, 15 is a thermocouple,
16 is a thermometer.

Claims (1)

[Claims] 1 A thin film is formed on a substrate by heating and melting the metal and evaporating the metal atoms in a vacuum, using an alloy expressed by the formula Ta _1-x Si _x , where x = 0.1 to 0.4. 1. A method for producing a Ta-based amorphous alloy thin film, the method comprising making a Ta-based amorphous alloy thin film amorphous using a vacuum evaporation device that forms a Ta-based amorphous alloy.