JPS6229550B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to boronized fibers that are mixed into matrix materials such as plastics, metals, ceramics, etc. to produce fiber-reinforced composite materials, and a method for producing the same.

Composite materials, which are made by combining materials with irregular shapes, are generally developed to achieve properties that cannot be possessed by the materials alone. In particular, it is easier to manufacture materials with excellent elastic modulus and strength in the form of fibers, so among composite materials, fiber-reinforced composite materials that combine fiber materials with appropriate matrix materials are
It is widely used as fiber-reinforced plastics (abbreviated as FRP) and fiber-reinforced metals (abbreviated as FRM). Glass and carbon are often used as reinforcing fiber materials, but boron and boronide fibers are also used because of their excellent elastic modulus.

The boron fibers for fiber composite materials as described above have conventionally been produced using an apparatus as shown in FIG. 1 and have a cross-sectional structure as shown in FIG. 2.

In the figure, 1 is a tungsten wire with a diameter of about 10μ, 2 is a supply spool for the tungsten wire 1, 3 is a support roll that supports the tungsten wire 1, and 4 is a chemical vapor deposition method (abbreviation) on the surface of the tungsten wire 1.
This is a CVD device that deposits boron using the CVD method. The CVD device 4 includes a preheating chamber 5 for cleaning the surface of the tungsten wire 1, a reaction chamber 6 for carrying out the CVD reaction, a mercury seal 7 for partitioning these, and a mercury seal 8 for energizing the tungsten wire 1.
The preheating chamber 5 has 9 hydrogen inlets for introducing hydrogen gas, 10 hydrogen outlets for discharging hydrogen gas, and a reaction chamber 6.
The reactor has 11 reactant gas inlets for introducing a mixed gas of boron chloride (chemical formula BCl ₃ ) and hydrogen, and 12 reactant gas outlets for discharging it. 13 is CVD
The boron fibers come from the device 4; 14 is a take-up spool for winding up the boron fibers 13; 15 is a boron layer forming the main body of the boron fibers 13;

Next, the process of forming the boron fibers 13 will be explained. Tungsten wire 1 comes from supply spool 2
It is introduced into the CVD device 4 through a mercury seal 7.

In the preheating chamber 5, hydrogen gas is introduced from the hydrogen inlet 9, and the tungsten wire 1 is heated from the mercury electrode 8.
When the wire is energized and heated to 1100 to 1200° C., the surface of the tungsten wire 1 is cleaned. In the next reaction chamber 6, while introducing a mixed gas of boron chloride and hydrogen from the reaction gas inlet 11, the tungsten wire 1 is
When heated to a temperature above ℃, boron B is precipitated on the surface of the tungsten wire 1 by the following ring element reaction: 2BCl ₃ + 2H ₂ → 2B + 6HCl ・Boron is a good conductor at high temperatures, so the surface of the precipitated boron is heated by direct current heating. The reaction temperature is maintained, and boron is continuously precipitated, and by the time it leaves the CVD device 4, as shown in Figure 2, boron has grown to a diameter of about 100μ around the tungsten wire 1, which was initially about 10μ. The boron fibers 13 forming the layer 15 are wound onto a winding spool 14 from which the boron fibers 13 can be obtained.

Conventional boron fiber 13 is CVD as shown in Figure 1.
Although manufactured by the device 4, in reality, a device for supplying hydrogen gas and boron chloride gas, a device for processing the gas after the reaction, and a tungsten wire 1 are not shown.
A heating power supply device, a vacuum pump device for removing air in the CVD device 4, etc. must also be added, resulting in an expensive device. In addition, tungsten is an expensive material and has poor workability, so tungsten wire 1 of about 10μ is expensive, and boron chloride used in the reaction is a special gas that is expensive and difficult to obtain. In the past, boron fibers produced in this way had the disadvantage of being expensive because the process had to start from the step of reacting boron chloride to produce boron chloride. Furthermore, since the outer surface of the boron fiber 13 is smooth,
When used as FRP or FRM, the properties of the composite material are greatly affected by the affinity between the fiber surface and the matrix. It also had the disadvantage of being difficult to use, such as having a large influence on the environment.

This invention was made in order to eliminate the drawbacks of the conventional ones as described above, and by heating the wire in a fume of boron fine particles and attaching boron fine particles around the wire, it is possible to reduce the cost. The purpose of the present invention is to provide a boronized fiber having a surface with fine irregularities.

An embodiment of the present invention will be described below with reference to the drawings. FIG. 3 shows an outline of the manufacturing equipment, in which 17 is a titanium thin wire, 2 is a supply spool for the strand 17, and 3 is a thin titanium wire.
18 is a boronized fiber obtained by boronizing the strand 17; 14 is a winding spool for the boronized fiber 18;
2 is a vacuum chamber for storing the above, 22 is an air supply port for introducing argon gas from the outside into the vacuum chamber 16;
3 is an exhaust port connected to an external vacuum pump device;
19 is an evaporation source using non-quality boron powder as raw material;
20 is a heating device for generating boron vapor from the evaporation source 19; 21 is an openable/closable shutter that covers the top of the evaporation source 19;

Next, the boronized fiber 1 is
The process of forming 8 will be explained. The inside of the vacuum chamber 16 is evacuated, the shutter 21 is closed, the heating device 20 is heated up, and when boron vapor is stably generated from the evaporation source 19, argon gas is introduced from the air supply port 22, When the pressure in the vacuum chamber 16 is set to about 100 Pa and the shutter 21 is opened, the boron vapor generated collides with argon atoms many times in the argon gas and is cooled, and the boron vapors adhere to each other due to collisions with each other. While growing as particles, they float in the vacuum chamber 16 to form a vapor. The fact that fine particles are formed during evaporation in such a gas is known, for example, from an article by Mr. Kimoto on pages 107 to 115 of the Bulletin of the Japan Institute of Metals, Vol. 12 (1973), No. 2. It is. Vacuum chamber 16 is created by support roll 3 of titanium wire.
The part suspended inside will be surrounded by the atmosphere of the fumes generated as described above, and when the support roll 3 is heated by applying electricity to the electrode and the wire 17, the surface of the wire 17 will be heated. The collided boron fine particles adhere, and boron atoms diffuse onto the surface of the wire 17. 18 is the boronized fiber thus formed, and its cross-sectional structure is shown in FIG. 4, consisting of the remaining strand 24 of the original strand 17 and the original strand It is composed of three types of layers: a boronized layer 25 formed by diffusing boron atoms on the surface of 17, and a boron particle layer 26 made of attached boron fine particles.

In the above example, the fumes of boron fine particles are generated by evaporating boron in an inert gas, but it is also possible to generate boron oxide by evaporating boron oxide in the vapor of a cyclic substance such as magnesium. Since boron oxide evaporates more easily than boron, it has the effect of simplifying the heating device. It is also possible to directly use commercially available amorphous boron powder as the boron fine particles constituting the atomizer, and it is possible to mix it into the inert or cyclic gas introduced as a dispersion medium atmosphere, or to blow it up during introduction. The same effects as in the above embodiment can be obtained by using the above embodiment.

In addition, in the above embodiment, titanium is used as the strand 1.
7 is shown, but conductive materials that have heat resistance equal to or higher than titanium and can form boronides, such as transition metal elements such as iron, nickel, tantalum, and tungsten, or carbon and The fibers may be made of an inorganic substance such as silicon carbide, and the same effects as in the above embodiments can be achieved.

As described above, according to the present invention, boronization is performed by attaching boron fine particles to the surface of the wire 17, so the device for gas supply and control is simplified, and the wire 17 is As there is no need to use hydrogen gas for the ring element reaction on the surface, there is a great deal of freedom in selecting materials such as titanium, which easily absorbs hydrogen gas. There is an effect that 18 can be manufactured. In addition, the surface of the produced boronized fiber 18 forms a boron particle layer 26 and has fine irregularities formed therein, and when used as a fiber-reinforced composite material, the bond with the matrix material becomes strong. This has the effect of improving overall characteristics.

[Brief explanation of the drawing]

FIG. 1 is a schematic side sectional view showing an example of a conventional boron fiber manufacturing apparatus, FIG. 2 is a longitudinal sectional view showing the cross-sectional structure of a conventional boron fiber, and FIG. 3 is an embodiment of the present invention. FIG. 4 is a schematic side cross-sectional view showing a boronized fiber manufacturing apparatus according to the present invention, and FIG. 4 is a longitudinal cross-sectional view showing the cross-sectional structure of the boronized fiber according to the present invention. 17...Element wire, 18...Boronized fiber, 24...
. . . Remaining portion of wire, 25 . . . Boronized layer, 26 .

Claims (1)

[Claims] 1. Boron fine particles are attached around the wire at high temperature, and boron atoms are diffused from the surface of the wire to form an intermediate boron layer, the remainder of the wire in the center, and boron on the surface. A boronized fiber characterized by being composed of three types of particle layers. 2. The boronized fiber according to claim 1, wherein the strand is a fiber of a transition metal element such as titanium, iron, nickel, tantalum, or tungsten. 3. The boronized fiber according to claim 1, wherein the strand is a fiber of an inorganic substance such as carbon or silicon carbide. 4. A method for producing boronized fibers, which comprises heating a strand in a fumes containing boron fine particles and depositing boron fine particles around the strand. 5. The method for producing a boronized fiber according to claim 4, wherein the boron fine particles are produced by evaporating boron in an inert gas atmosphere. 6. Claim 4, wherein the boron fine particles are produced by evaporating boron oxide in a cyclic gas atmosphere.
A method for producing a boronized fiber as described in Section 1. 7. Claim No. 7, characterized in that the fume containing fine boron particles is generated by introducing fine powder of amorphous boron into an inert gas or a cyclic gas. 4. The method for producing a boronized fiber according to item 4. 8. The fume containing fine boron particles is generated by blowing up fine powder of amorphous boron at the time of introduction of an inert gas or a cyclic gas used as a dispersion medium. A method for producing a boronized fiber according to claim 4.