JPS6026828B2 - 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 structure material, which aims to improve the film quality and mechanical properties of the shelf element constituting the shelf element structure material and to improve the production yield, as well as to improve the production yield of acoustic materials, especially acoustic materials. It is an object of the present invention to provide a cantilever for a pickup cartridge having excellent acoustic characteristics.

Shelf elements have a hardness second only to that of diamond, and are extremely dust resistant, making them useful materials for cutting tools, slider core parts, bearings, etc. It has the excellent feature of having the highest ratio (rate/density) of any existing material.

This property means that the sound wave and propagation velocity are the highest among existing materials, making it useful as an acoustic material, especially cantilevers for cartridges. Conventionally, metals such as aluminum alloys and titanium alloys have been used as cantilevers for cartridges, but both have a lower comparability ratio than shelving elements, and their frequency characteristics have a Takagi resonance frequency of n( In the range of 2 to 1 female HZ (normally 1 female HZ to 40 KHZ) or less, the response tends to decrease, so-called middle sag development, 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 cantilever for cartridges using shelf elements has been awaited as a solution to the drawbacks of these known materials. In particular, cantilevers for cartridges made of taber pipes are said to greatly contribute to flattening the frequency response in the high range of 4 HZ or more, compared to cantilevers for cartridges made of flat pipes, and their appearance is eagerly awaited. It is difficult to obtain products using shelving elements in a delicate structure by methods such as casting or rolling, and for this reason, in most cases, when producing various products using shelving elements, materials other than shelving elements are used. Vapor deposition, sputtering, or chemical vapor deposition (CVD) on a substrate made of
It is used as a composite with a shelf element film formed by such methods. Among the above-mentioned conventional shelf element film forming methods, CVD
It is believed that this method can yield the highest quality coating.

In the CVD method, crystalline (8-rombohedral, Q-rombohedral, tetragonal) side elements, amorphous shelf elements, or a mixture of these elements can be obtained by changing the production conditions. Conventionally, shelf elements deposited on a substrate often have poor mechanical properties due to inherent strain, microrack, etc., and when the substrate is removed by an appropriate method, In these conventional methods, the shelf elements were destroyed without exception during the process of removing the substrate. This shows the magnitude of the inherent distortion.
The inventors solved the problems of these conventional examples by coating the substrate with chromium, a shelving of chromium, an alloy of chromium and iron, or a shelving of this alloy, and using infrared heating. This problem was solved by uniformly heating and generating heat from a portion of the taper provided on the base.

By this method, it is possible to provide a tapered pipe structural material consisting of shelf elements alone, which does not cause destruction of the shelf elements as in the past, exhibits excellent mechanical properties, and has a good appearance.
Further, the tapered vipe structural material consisting of the side element alone was excellent as a cantilever for a cartridge. The method of the present invention will be specifically explained below.

First, as a method for forming a pyramidal and conical taper on the surface of a base made of metals such as tantalum, niobium, titanium, tungsten, molybdenum, and nickel, for example,
There is a method of forming Taber by chemical etching using strong acid or the like.

Other methods include a method in which a mold having a desired shape is created and formed by applying weight or hammering, or a method in which a desired shape is formed by polishing. Next, the tapered substrate is coated with chromium, a shelving product of chromium, an alloy of chromium and iron, or a shelving product made of this alloy by the method described above.

The thickness of this shelving film is preferably 0.2 to 10 m.
There are various methods for coating, including plating, immersion treatment,
The sputtering method, the coating method, and the CVD method can be used, but the sputtering method is the best because of its ease of control. Next, CVD is performed using this as a support base.

The method of forming shelf elements on a tapered substrate using the CVD method involves uniformly heating the tapered substrate to generate heat using external heating such as infrared heating, resistance heating, or high frequency heating. , the shelf elements are precipitated by a reductive decomposition reaction as shown in the following equation. Wave X3 (10) Pan 21 wave (10) Thin
The raw material gas used in method D includes other hydrides of BX3.

Next, the sample having the tapered shelf element coating deposited on the surface of the supporting substrate by CVD in the reaction tank as described above is taken out from the reaction tank, cut into desired lengths, the substrate is removed, and the sample is placed on a shelf. The purpose is to manufacture a tapered pipe structural material consisting of a single element.

The effect of the present invention is to obtain a tapered pipe structural material consisting of only shelf elements, which has an excellent appearance and excellent mechanical properties. Furthermore, in the present invention, the method for precipitating shelf elements is limited to the CVD method because the vacuum evaporation method has a slow deposition rate and is problematic in terms of cost. Even if there is, or C under normal pressure
Even the VD method is effective. Furthermore, in order to evaluate the mechanical properties and acoustic properties of the tapered pipe structural material itself, which consists of the produced shelf elements alone, we finally removed the base material, which was done mainly by chemical methods. Ta. Examples of the present invention will be described below in comparison with conventional methods.

A non-tapered tantalum and tungsten base with a maximum light weight of 250 French m, a minimum diameter of 150 French m, and a length of 5 sails was created by a polishing method, and then chromium and a chromium-iron alloy were sputtered to a thickness of 0.5 mm. 7rm coated.

The substrate thus produced is as follows. {11
Tantalum, ■Tungsten, {31k. Tungsten coated with chromium, '4} Tungsten coated with chromium, [5}
A wire made of five types of tantalum coated with an alloy of iron and chromium was used. Each of these was installed in a reaction tank, and a mixed gas of hydrogen chloride (BCso3) and hydrogen (day2) was supplied at a rate of 250'/min for the former, and at a rate of 1so/min for the latter. The ratio was agreed. Then, the supporting substrate was heated to 1150 qo by infrared heating to generate heat, and
After precipitating shelf elements to a thickness of 20 mm on the surface of the substrate holding the sand gap, it was taken out from the reaction tank, cut into 5 pieces, and the substrate was removed. The sample obtained as described above was placed in a state where both ends of the four side spans were supported, a load was applied to the center at one point, and the mechanical strength was evaluated based on the load at which a crack occurred.

The number of samples was 20 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 ship.
Those marked with a circle are those according to the present invention, and the others are conventional methods.

As is clear from the above results, it can be seen that according to the method of the present invention, the mechanical strength and the yield of the shelf tapered pipe structural material are significantly higher than those using the conventional method.

Furthermore, in order to evaluate the acoustic characteristics of the shelf tapered pipe structure material according to the present invention, the obtained shelf tapered pipe structure material was processed into a cantilever for a cartridge, and its properties were evaluated. As a result, conventionally known materials, such as aluminum. The so-called mid-sag phenomenon in frequency characteristics, which was considered a drawback with alloys or titanium alloys, as well as flatness at high frequencies of 4 HZ or higher, and transient characteristics that affect followability, etc., have been improved by several steps. . In addition, the shelf element coating with high treadability without distortion or microcracks has a wide range of uses as a mechanical component.

[Brief explanation of drawings]

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.

Claims (1)

[Claims] 1. Forming a pyramidal or conical taper on the surface of a supporting substrate, then heating the substrate using high frequency heating, infrared heating, or resistance heating, and applying chemical vapor deposition onto the substrate. A method for producing a boron structural material, characterized by forming boron by. 2. The method for producing a boron structure according to claim 1, wherein the supporting base is made of a metal selected from the group consisting of mortar, niobium, titanium, tungsten, molybdenum, and nickel. 3. The support base is made of mortar, niobium, titanium, tungsten, molybdenum, or nickel, and is made of chromium, a boride of chromium, an alloy of chromium and iron, or this alloy coated with a boride. A method for producing a boron structural material according to claim 1, characterized in that: