JPS58172297A - Manufacture of sic whisker - Google Patents

Abstract

PURPOSE:To inexpensively manufacture SiC whiskers in a high formation yield, by mixing cullet or a cullet-silica sand mixture with furnace carbon black and by heating the prepared mixture in a nonoxidizing atmosphere. CONSTITUTION:Cullet contg. SiO2 and Na2O as principal components or a mixture of the cullet with silica sand is used as a starting material for a silicon source. The starting material is mixed with 60-400wt% furnace carbon black having >=50ml/100g DBP oil absorption and a grain aggregated structure, and the mixture is heated at 1,300-1,800 deg.C in a nonoxidizing atmosphere to manufacture SiC whiskers. The cullet is pulverized scrap glass and is very inexpensive. It has an almost uniform composition and almost uniform properties when regularly manufactured products are used as a source, so SiC whiskers of high performance can be manufactured in a high yield using inexpensive starting materials.

Description

[Detailed description of the invention] 81C whiskers have excellent physical properties such as specific strength, specific modulus of elasticity, heat resistance, and chemical stability, so they are expected to be used as composite reinforcing materials for metals or glass. However, in order for this to be widely put into practical use, the material cost of k must be low.

The present invention provides a method for obtaining BIC whiskers in high yield using extremely cheap 1i&silicon 1[J[kg], and aims to provide a method for producing high quality 81 (whiskers) at a low manufacturing cost.

That is, the present invention provides 810. Cullet containing JJa,o as the main component or a mixture of this and silica sand is used as a silicon raw material, and DBP oil absorption of 50a is added to this as a carbon material.
The structural feature is that furnace carbon black having an agglomerated structure of particles of 17,100 or more is mixed at a concentration of 60-400% by weight and then heated to a temperature of 1300-1809° C. under a non-oxidizing atmosphere.

The cullet used in the production of glass is usually crushed glass scrap that is heated into patches as one of the Kg materials used in glass manufacturing, and is an extremely inexpensive industrial material. This component varies depending on the composition of the gas, but the composition, components, and properties of those sourced from regularly produced products are almost constant. In this threat, 1310. Cullet with a composition mainly composed of
50@t) A fine powder containing 810 mm of ingredients and having a particle size of 150 mesh or less is effectively applied.

For the vertical members, 50 DBPa weight of Straftia-0iltIII of 7 Arness carbon plaque obtained by thermally decomposing petroleum-based or coal-based O heavy hydrocarbon oil was used.
m/100f or more is used. Furnace carbon platter has a surface texture and particle structure that is different from ordinary carbonaceous materials such as coke powder and graphite powder, and is itself qualified as a carbonaceous material.
Particles with an agglomerated structure with an oil absorption of 40 m/100 p or more undergo the 81C cuisker production reaction smoothly and act effectively to form the 4192 spaces necessary for crystal elongation. , resulting in an increase in production yield O.

The furnace carbon platter carbon material needs to be mixed with the silicon raw material at a ratio of 60 to 400% by weight.If the mixing ratio is below this range, a large amount of fine particulate 81 CwI crystals will be generated, which will essentially turn into whiskers. Printing the decline in yield. In addition, blending more than 4 IN of carbonaceous material does not work to increase the whisker yield, but rather makes the after-asahi burial due to the increase in the residual carbonaceous material more difficult.

The silicon wire raw material and the carbon material are heated sufficiently and uniformly.

The raw material system further contains MaCl and N as generation space forming materials.
If an alkali metal halide such as aF, KCI or an alkaline earth metal halide such as MPCI, CaF, etc. is present in the coexistence, a space effective for whisker growth will be formed inside the raw material system during heating. line J
11. It functions as a 7 lux that promotes the vaporization of silicon, giving a material effect of 1 that further promotes the production yield and crystal elongation.
[It is mixed into the raw material system at a mixing ratio of 45 to 200 Jl to the raw material, or it is made to coexist by means such as collecting it at the bottom.

The raw material is charged into a reaction volume ii) made of a heat-resistant material such as graphite and then heated. The reaction vessel is heated to 1500-1800° C., preferably 1500° C., in a non-oxidizing atmosphere by wrapping the surrounding area with a curling material such as coke grains and heating with electricity. 15
Keep the image at a temperature of 0°C for at least 2 hours.
appear.

In the heating bath, the silicon component and the carbonaceous component in the raw materials are converted into 81G whiskers in the form of small, fibrous complexes through a gas phase reaction, and finally they are formed inside the carbon black grain structure or throughout the mutual space. In summer, striped KIF grows.

The unreacted stringer components in the product are removed by incineration.

The products after the incineration step 11 are all pale green-white StC whiskers except for a small amount of particulate 8iC, and the production yield with respect to the silicon-based raw material is close to that of ring brass agglomeration. The properties of the whisker are a θ-type single crystal with no lattice defects and a good aspect ratio of 0.2-0, 5 μm, and 50-500 μm.

In this way, according to Jujoi@, it is possible to produce 81C whiskers of I4 quality with good yield using extremely cheap aluminum laminates, so it can be produced on an industrial scale with low JI.
can be produced at low prices.

Hereinafter, zero anatomy will be explained based on examples.

Example! .

810.75%, Ma, 0 24%, other CaO, Mul! ,0. Cullet with a composition containing one component such as
(particle size of 150 mesh or less) was made into silicon IIJl [1iI], and DBP oil absorption (J method 8-me method) was added to this as a carbon material.
A8M F-Hs class 7 Arness carbon black (a8mA875H', Tokai Capos Taruyuu) having the characteristics of 50d/100y and iodine adsorption amount of 104q/p was sufficiently uniformly mixed with different blending ratios.

Next, 50% of each of the mixed raw materials. Of 11701111%
The waste was loosely filled into a high-purity graphite reaction vessel with a capacity of 150 tons, a bad lead lid was attached to the top of the reaction vessel, and the waste was transferred to an Acheson lid electric furnace, and the waste was encapsulated with a coke grain backing. The furnace was energized to raise its temperature, and the inside of the furnace was kept in a non-oxidizing atmosphere for 16 hours.
The reaction was completed by heating to a temperature of 50°C for 4 hours.

The Kashima-treated karimaru was heated and mixed under the same conditions as in Example 1.

The generated 1i11C whisker has β similar to that of implementation g41.
Atsue is a stylish single crystal with main body ON, xaclsM1pC
When the coexistence ratio of 4. was in the range of 45 to 200% by weight relative to the bare silicon raw material, the production reaction was improved, and an increase in the asbetato ratio and a slight tendency for yield improvement were observed.These results are shown in Table IK. Circle.

In addition, alkali metals such as 1iar, Car, etc.
Roughly similar results were obtained when alkaline earth metal halides/compounds were heated in Maruba.

Claims (1)

[Claims] L 1310. And cullet mamaru whose main components are Ha and O is a mixture of this and silica sand as a silica raw material, and DBP oil collecting amount of 50 m/100 j1 or more is added to this as a carbon material.
7 Arnes carbon black with particle agglomeration structure 6
A method for producing 81C whiskers, which comprises mixing at a ratio of 0 to 400 weight IJII and then heating to a temperature of 1300 to 1800°C in a non-oxidizing atmosphere. 2. The method for producing 81C Quisker according to Claim JI 11, wherein 45 to 200 weight parts of an alkali metal or alkaline earth metal halide is co-existed with the 2-silicon raw material.