JPS6012969B2 - Manufacturing method of boron structural material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a shelf element structural material, and aims to improve the film quality and mechanical properties of the shelf element constituting the shelf element structural material, as well as the manufacturing yield. In particular, the present invention provides a shelved horizontal structure suitable as a cantilever for cartridges.

Shelf elements have a hardness second only to that of diamond, and have extremely high wear resistance, so they are useful materials for cutting tools, sliding machine parts, bearings, etc., and also have a high specific modulus ( It has the excellent characteristic of having the highest elastic modulus/density among currently known materials.

This property means that the propagation velocity of sound waves is the highest among existing materials, making it useful as an acoustic material, particularly as a cantilever for cartridges. Conventionally, metals such as aluminum alloys and titanium alloys have been used as cantilevers for cartridges, but both have a lower specific elastic modulus than that of shelf elements, and their frequency characteristics have a Takagi resonance frequency fo (usually 10 kHz to 40 kHz). There is a drawback that a drop in response, a so-called sagging phenomenon, tends to occur in the range of about 10K to about 10K, and it is difficult to obtain flat frequency characteristics.

Furthermore, there is a drawback that good transient characteristics, which affect the followability of the pickup cartridge, cannot be obtained. The appearance of a force-torage cantilever using shelving elements has been awaited as a solution to the drawbacks of these known materials. Among them, it is said that the cartridge cantilever of the tapered pipe has a greater contribution to flattening the frequency characteristics in the high range of 4 skinboards or more, compared to the cartridge cantilever of the flat shelf pipe.
However, it is difficult to obtain shelving element applied products in a delicate structure by methods such as casting or rolling, and for this reason, various shelving element applied products are In most cases, it is used as a composite in which a shelf element film is formed on a substrate made of a material other than shelf elements by vapor deposition, sputtering, chemical vapor deposition (CVD), or the like. Among the above-mentioned conventional shelf-base film forming methods, the CVD method is considered to be able to obtain the highest quality film.
In the CVD method, crystalline (8-rombohedral, Q-rombohedral, tetragonal) shelf elements, amorphous (amorphous) shelf elements, or a mixture of these can be obtained by changing the production conditions. In general, shelving elements mainly composed of amorphous materials are considered to be superior in terms of mechanical properties such as tensile strength. However, since the CVD method that generates shelf elements generally utilizes a thermal decomposition reaction, when the substrate is provided with a pyramidal or conical taper and heated by electricity, the heat generation of the substrate becomes uneven. The resulting film deposited on the substrate has different properties in proportion or inverse proportion to the unevenness of heat generation, which significantly impairs the appearance and mechanical strength. Furthermore, the mechanical properties of shelf elements conventionally deposited on a substrate are often poor due to inherent strain, microcracks, etc. Furthermore, when the inventors removed the substrate using an appropriate method, the shelf elements produced by these conventional methods were destroyed without exception during the process of removing the substrate. This shows the magnitude of the inherent distortion. The inventors solved these conventional examples by applying appropriate treatment to the base, molding it into two pyramids or cones that face each other and share a vertex, and providing a heat sink near the vertex. This solves the problem.

By the method of the present invention, it is possible to provide a tapered pipe structural material consisting of only fence elements, which exhibits excellent mechanical properties and has a good appearance, without the destruction of horizontal shelf elements as in the past. Moreover, the tapered pipe structure material consisting of the shelf element alone was excellent as a cantilever for a cartridge. The method of the present invention will be specifically explained below. First, tantalum, niobium, titanium, tungsten, molybdenum,
Substrates made of a nickel alloy are formed into two pyramid or cone shapes that face each other and share a vertex.

For example, the taper may be formed by chemical etching using strong acid, or other methods include creating a mold with the desired shape and forming it by applying weight or tapping, or by polishing the desired shape. There are various methods for forming shapes. Next, the tapered substrate obtained by the above method was coated. chromium, shelving of chromium, alloys of chromium and iron, or shelving made of these alloys. The thickness of this shelving film is 0.2
~10 mountain surface is desirable. Various coating methods can be used, including plating, immersion plate treatment, sputtering, vapor deposition, and CVD, but the sputtering method is the best in terms of ease of control.

Next, as shown in FIG. 1, the coated tapered substrate A
A heat radiating plate B made of a metal having a melting point of 650° C. or higher is installed near the apex of , and CVD is performed using this as a supporting substrate.

In addition, when selecting the material of the heat sink, CVD is 8.
This is determined by the fact that it is carried out between 00:00 and 125,000, but since the degree of heat dissipation varies depending on the shape or size of the heat sink, it is actually measured rather than the standard one, and metals below this melting point are also I can't say for sure that it's impossible. In the method of forming shelf elements on a substrate by the CVD method, heating is performed using an electric heating method, and shelf elements are precipitated by a reductive decomposition reaction as shown in the following formula. Wave X3 (10) Pan 21 $ (
10) BX3 as a raw material gas used in the CVD method (where X is a halogen element such as CI, Br, or 1)
In addition, there are hydrides, etc. Next, the sample having the tapered shelf element film deposited on the surface of the supporting substrate by CVD method in the reaction tank as described above was taken out from the reaction tank, the heat sink was removed, and the sample was cut to a desired length. A tapered pipe structural material consisting of only shelf elements is manufactured by removing the above. The purpose of the present invention is to obtain a tapered pipe structural material made of a single shelf element that has excellent appearance and excellent mechanical properties.
The reason for limiting the method to the VD method is that the vacuum evaporation method has a slow deposition rate and is problematic in terms of cost.
This is valid even for VD.

In addition, in order to evaluate the mechanical properties and acoustic characteristics of the tapered pipe structural material itself, which is made from the manufactured shelf element alone, we finally removed the base material, but mainly by chemical methods. Ivy.

Examples of the present invention will be described below in comparison with conventional methods.

The tantalum and tungsten base, which has a coin shape with a maximum diameter of 250 cm, a minimum diameter of 150 cm, and a length of 5 cm, and has a tapered shape sharing the apex as described above, is created by a polishing method, and is made with 3 vertical bars. A tantalum or aluminum heat sink having one rib horizontally and 0.3 ribs in thickness was installed near the apex. The substrates thus prepared were: 1 tantalum, 2 tungsten, 3 chromium-coated tantalum,
4 Tungsten coated with chromium, 5 Tantalum coated with iron-chromium alloy, 6 Tantalum with tantalum heat sink, 7 Tantalum with aluminum heat sink, 8 Tantalum coated with chromium with tantalum heat sink, 9 Aluminum Wire rods made of 11 types were used: chromium-coated tantalum with a heat sink installed, tantalum coated with iron-chromium alloy with a 11 tantalum heat sink installed, and chromium-coated tungsten with a 10 tantalum heat sink installed. These were installed in a reaction tank, and hydrogen chloride (BC13) and hydrogen (
Day 2) was supplied at a rate of 250 M/min for the former, and at a rate of 1 pm/min for the latter.
Then, electricity was applied to the supporting substrate to heat it to 1150 qo, and the shelf elements were deposited to a thickness of 2 on the surface of the supporting substrate, which was held for 6 days.
After 0 μm was deposited, it was taken out from the reaction tank, the heat sink was cut off, the heat sink was cut into 5 pieces, and the substrate was removed. The sample obtained as above was supported at both ends of the 4-rib span, and a concentrated load was applied to the center.
Mechanical strength was evaluated based on the load at which cracks occurred.

The number of samples was 2 for each, and the average value is shown in the table below. The table below also shows the yield when removing the base and obtaining the shelf element tapered pipe structural material. *1) Sample pigs Those marked with K○ are those according to the present invention, and the others are those according to the conventional method.

As is clear from the results in the above table, according to the method of the present invention, the mechanical strength, yield, and appearance of the shelf element tapered pipe structural material are significantly superior to those using the conventional method. Recognize.

In addition, in order to evaluate the acoustic properties of the shelved element tapered pipe structural material according to the present invention, the obtained shelved element tapered pipe structural material was processed into a cantilever for a cartridge, and its characteristics were evaluated. As a result, as shown in Figure 2, the so-called mid-sagging phenomenon in frequency characteristics, which had been considered a drawback with conventionally known materials such as aluminum alloys, as well as the transient characteristics that affect followability, etc., were significantly improved. In addition, the shelving film, which has a high elastic modulus and is free from distortion and microcracks, has a wide range of uses as a mechanical component.

[Brief explanation of drawings]

FIG. 1 is a side view showing one step of the manufacturing method of the present invention, and FIG.
The figure is a diagram illustrating the frequency characteristics when the shelf element tapered pipe structural material according to the present invention is used as a cantilever for a cartridge in comparison with a conventional material. A: Base, B: Heat sink. Section 1 figure leopard 2 figure

Claims (1)

[Scope of Claims] 1 Support substrates are formed into tapered shapes of a pyramid and a cone that face each other and share a vertex, and a heat radiator made of a metal having a heat radiating function is installed near the apex of the base body. A method for producing a boron structural material, which comprises: heating the supporting substrate by applying an electric current to form boron on the supporting substrate by a chemical vapor deposition method. 2. The method for producing a boron structural material according to claim 1, wherein the supporting base is made of a metal such as tantalum, niobium, titanium, tungsten, molybdenum, or nickel. 3. The method for manufacturing a boron structural material according to claim 1, wherein the heat sink is made of a metal having a melting point of 650° C. or higher. 4. A patent claim characterized in that the supporting substrate is made of tantalum, niobium, titanium, tungsten, molybdenum, or nickel coated with chromium, a boride of chromium, an alloy of chromium and iron, or a boride of this alloy. A method for producing a boron structural material according to item 1.