JPS6099005A - Production of silicon carbide fiber - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] <Industrial Application Field> This invention uses silicon carbide IMi navy blue! ll! I create I
There is something about the simplest method.

<Conventional technology> The use of SiC fibers to reinforce and strengthen Reramix, metals and synthetic wood 11F7 has also increased the U++ taste.
This is coming. If U゛, this S1C woven fabric has high thermal stability and excellent mechanical properties.
) O'CL F ) F (1) QIlI'tM (?I
A-(This is because it is a material that does i. SiclM;
The method of the present invention for producing strings aims to use zero-polycarbosilanes. The conventional methods are generally complex, require relatively expensive raw materials, and also result in products that are relatively expensive to manufacture. The increasing demand for SiC fibers could be met if simpler methods were developed using cheaper and more readily available raw materials.

<Problems to be solved by the invention> The purpose of the invention is to produce SiC fibers suitable for making high-density, high-strength, and high-toughness SiC composites, or suitable as heat insulating materials in oxidizing environments. The objective is to provide a simple and relatively inexpensive method to do so.

<Means for solving the problems> In this invention, rayon fibers are carbonized by thermal decomposition, and the resulting carbon fibers are reacted with colloidal silicic acid. Consisting of: (1) Short rayon three-part fiber (length 75071m,
ii) Homogenizing the mixture of colloidal silicic acid and colloidal silicic acid in water; (2) removing water by drying the mixture in air at 120°C; (3) removing the water by drying the mixture in air at 120°C; The mixture was placed under argon for 8 (1 (+-111
11 (Heating at 1-0 to carbonize the rayon fibers;
(4) The above mixture was heated in argon (1550...
1! One culm heated at + 00'C to produce pure SiC fibers.

According to the experimental results of this method, the product fibers are β-8IC
There was no other discernible culm crystalline phase. This method is extremely simple and is therefore not suitable for large-scale commercial use.
DJ ability is about applying it.

Take a continuous rayon filament, cut it into pieces (for example, 750μWl in length), and mix it with 71cm of silicate acid in water.The mixing ratio at this time is 1 part of silicic acid in gp ratio. Take 3 parts of rayon.

The water opening used is typically the feedstock fit 'I O
1 which is about 1 gallon (about 3,785j!) for H
The mixture was dried in air at 120°C to remove water and carbonized by heating to 1000°C in Ar at a rate of 10°C per hour and holding for 51 hours.

This pyrolysis mixture is reacted in Ar at 1500-1900° C. for 1-3 hours to produce SiC fibers.

<Example> 100 mono-L1 silicic acid (grade ll8-.

Cut rayon (length 75
0z1m x diameter 121℃m, Beaunit l”
1 ber CO3 (US 1ffi;
Manufactured in Bethtown), M 1crofH+er Co,
(Cut at Bowdocket 1~, Rhode Island, USA)
and -C were mixed in about 0.5 gallons of water (about 1.893 J2') using a Warlink blender on low speed for about 2 minutes. The mixture was dried in air at 120°C for 16 hours and then dried at 10°C in argon.
It is thermally decomposed by heating from room temperature to 1,000°C at a rate of 1,000°C and holding it for 1 hour. Ar the final reaction
The process was carried out at 1575° C. for 3 hours to produce β-3iC fibers.

According to microscopic examination and xm diffraction results, #A navy blue made in this example had β-8IC'r: and no other appreciable crystalline phases. The appearance of this SiC fiber maintained the wavy morphology of rayon fibers and had rough surface characteristics.

<Effects of the Invention> Very small particles of colloidal silicic acid (Y) come in contact with carbonized fibers during the complete reaction to β-8iC formation. This method is relatively new, and since the fibers and colloidal silicic acid are relatively cheap, it provides a low-cost, high-quality SiC fiber product. .

Other refractory metal carbides IQI [l (e.g. l, ij
It is anticipated that tantalum oxide (Tantalum oxide) may also be produced by the method of the present invention using rayon and a corresponding "1" oxide with appropriate reaction conditions.

Claims (1)

[Claims] 1. A step of homogenizing a mixture of rayon fibers and colloidal silicic acid in water;
heating the mixture with silicic acid to remove water; heating the mixture with silicic acid to dry rayon fibers in an inert atmosphere to carbonize the carbonized rayon fibers; A method for producing silicon carbide fibers, which comprises the step of reacting the mixture of fiber cloth and colloidal silicic acid in an inert atmosphere (converting carbonized rayon fibers into silicon carbide fibers. 2. Homogeneous) A method according to claim 1, wherein the mixture of dried rayon fibers and colloidal silicic acid is heated at a temperature of about 120°C to remove water.3. 4. The method of claim 1, wherein said mixture of carbonized rayon fibers and colloidal glucic acid is heated to a temperature of about 1550-1900° C. to carbonize the rayon fibers. Claim 1, in which the carbonized rayon fibers are converted into silicon carbide fibers by heating at a temperature e of °C.
The method described in