WO1982001545A1 - Silicon carbide bodies - Google Patents

Silicon carbide bodies Download PDF

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Publication number
WO1982001545A1
WO1982001545A1 PCT/GB1980/000182 GB8000182W WO8201545A1 WO 1982001545 A1 WO1982001545 A1 WO 1982001545A1 GB 8000182 W GB8000182 W GB 8000182W WO 8201545 A1 WO8201545 A1 WO 8201545A1
Authority
WO
WIPO (PCT)
Prior art keywords
silicon carbide
particles
self
silicon
mixture
Prior art date
Application number
PCT/GB1980/000182
Other languages
French (fr)
Inventor
Energy Authority Uk Atomic
Original Assignee
North Bernard
Kennedy Peter
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by North Bernard, Kennedy Peter filed Critical North Bernard
Priority to EP80901959A priority Critical patent/EP0063112A1/en
Priority to PCT/GB1980/000182 priority patent/WO1982001545A1/en
Priority to JP55502388A priority patent/JPS57501578A/ja
Priority to DE803050618A priority patent/DE3050618A1/en
Publication of WO1982001545A1 publication Critical patent/WO1982001545A1/en

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Classifications

    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/515—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics
    • C04B35/56—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on carbides or oxycarbides
    • C04B35/565—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on carbides or oxycarbides based on silicon carbide
    • C04B35/573—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on carbides or oxycarbides based on silicon carbide obtained by reaction sintering or recrystallisation
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B32/00—Carbon; Compounds thereof
    • C01B32/90—Carbides
    • C01B32/914—Carbides of single elements
    • C01B32/956—Silicon carbide
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B32/00—Carbon; Compounds thereof
    • C01B32/90—Carbides
    • C01B32/914—Carbides of single elements
    • C01B32/956—Silicon carbide
    • C01B32/963—Preparation from compounds containing silicon
    • C01B32/97—Preparation from SiO or SiO2
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00—Particle morphology
    • C01P2004/60—Particles characterised by their size
    • C01P2004/62—Submicrometer sized, i.e. from 0.1-1 micrometer
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2006/00—Physical properties of inorganic compounds
    • C01P2006/10—Solid density
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2006/00—Physical properties of inorganic compounds
    • C01P2006/12—Surface area
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2006/00—Physical properties of inorganic compounds
    • C01P2006/80—Compositional purity

Definitions

  • This invention relates to silicon carbide bodies a in particular, to the production of bodies of self-bond silicon carbide by reaction sintering of a preformed mixture of particles of silicon carbide and carbon in the presence of molten silicon.
  • reaction sintering is hereinafter referred to as "siliconising” and one method of siliconising is described in UK patent Specification 1,180,918.
  • the present invention consists in a self-bonded silicon carbide body produced by siliconising a preformed mixture of particles of carbon and silicon carbide wherein the silicon carbide in the mixture is in the beta form and the silicon carbide in the body has a mean grain size in the range 0.1-5 microns.
  • Tb.e present invention also consists in a method of producing a self-bonded silicon carbide body by siliconising a preformed mixture of particles of carbon and silicon carbide in the beta form, the silicon carbide particles having a mean surface area in the range 0.5-20 square metres per gram, and in a self-bonded silicon carbide body so produced.
  • a self-bonded silicon carbide body in accordance with the invention when compared with a self-bonded silicon carbide body produced using particles of aloha silicon carbide has improved properties, in particular in the extent and nature of deformation and microcracking around indentations. For example in 500g load knoop indentation tests cracking was much more localised and damage far less extensive. Also there is a greater dependence of hardness on load and may be higher hardness at low loads. These results indicate that bodies in accordance with the invention will behave in general in a more plastic manner have less tendency to crack catastrophically and show greater wear resistance and surface toughness.
  • the coherent mixture of silicon carbide and carbon may be formed prior to siliconising by any convenient method such as extrusion, injection moulding, slipcasting or pressing.
  • the fine silicon carbide particles in beta form are preferably produced by passing silicon monoxide through a bed of particulate carbon which is converted to silicon carbide powder, the silicon monoxide vapour being generated by heating a mixture of silica and silicon separately from the bed of particulate carbon.
  • the silicon carbide powder had a surface area of 3.7 m 2 /g and the carbon powder consisted of crystallites which formed agglomerates with a surface area of about 6 m 2 /g.
  • the pellet was extruded through a profiled die to form components of uniform cross-section and the extrudate was cut and heated to 400°C to volatilise the binder.
  • Example 2 A mix containing carbon and beta-silicon carbide powders of the same size as in Example 1 but in the ratio 0.25:1 by weight, and sufficient polymeric binder to form a hard rigid body on compaction, was pressed isostatically at about 100 MN/m 2 to form a component which was subsequently 'green machined', using a diamond tool. The 'green' material was heated to 400°C to volatilise the binder an was then fired at 1650°C in the presence of molten silicon to convert it to a 90% dense silicon carbide containing free silicon.
  • Example 3 A mix containing carbon and beta-silicon carbide powders of the same size as in Example 1 but in the ratio 0.25:1 by weight, and sufficient polymeric binder to form a hard rigid body on compaction, was pressed isostatically at about 100 MN/m 2 to form a component which was subsequently 'green machined', using a diamond tool. The 'green' material was heated to 400°C to volatilise the bin
  • Beta silicon carbide powder surface area 2 m 2 /g, was mixed with carbon black, surface area 5 m /g, in the ratio 1:0.4 by weight.
  • An aqueous slip was made up and a slip-cast slab was made.
  • the slab was dried and siliconised at 1650oC for 2 hours in a vacuum of 1 torr. After cooling excess silicon was removed from the surface by abrasive blasting and the density of the slab was found to be 3.04g/cm 3 that is, it contained 19% by volume free silicon.
  • the mean grain size in the slab was approximately 0.7 micro
  • Example 4 Beta silicon carbide powder, surface area 4.4 m 2 /g vss mixed with carbon black, surface area 6 m 2 /g, in the ratio of 1:0.3.
  • a slab was formed as in Example 3 and siliconised at 1600oC for 30 minutes.
  • the density was 2.92 g/cm 3 (33% by volume free silicon) and the mean grain size was 0.5 microns.
  • Example 5 A beta silicon carbide powder, surface area 0.8 m 2 /g was mixed with graphite powder, surface area 60 m /g in the ratio 1:0.4 by weight. Binder and lubricants were mixed in and rods 4 mm in diameter were extruded. After removal of the binder the rods were siliconised at 1650°C for 2 hours in a vacuum of 1 torr. Density of the rod was 3.12 g/

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Ceramic Engineering (AREA)
  • Inorganic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Structural Engineering (AREA)
  • Ceramic Products (AREA)

Abstract

A self-bonded silicon carbide body produced by siliconising a preformed mixture of particles of carbon and silicon carbide in the beta form has a mean grain size in the range 0.1-5 microns. Such a silicon carbide body may be produced using silicon carbide particles having a mean surface area in the range 05-20 square metres per gram. The silicon carbide particles may be produced by heating a mixture of silica and silicon to generate silicon monoxide vapour and passing the vapour through a bed of particulate carbon.

Description

Silicon Carbide Bodies.
This invention relates to silicon carbide bodies a in particular, to the production of bodies of self-bond silicon carbide by reaction sintering of a preformed mixture of particles of silicon carbide and carbon in the presence of molten silicon. Such reaction sintering is hereinafter referred to as "siliconising" and one method of siliconising is described in UK patent Specification 1,180,918.
The present invention consists in a self-bonded silicon carbide body produced by siliconising a preformed mixture of particles of carbon and silicon carbide wherein the silicon carbide in the mixture is in the beta form and the silicon carbide in the body has a mean grain size in the range 0.1-5 microns. Tb.e present invention also consists in a method of producing a self-bonded silicon carbide body by siliconising a preformed mixture of particles of carbon and silicon carbide in the beta form, the silicon carbide particles having a mean surface area in the range 0.5-20 square metres per gram, and in a self-bonded silicon carbide body so produced.
A self-bonded silicon carbide body in accordance with the invention, when compared with a self-bonded silicon carbide body produced using particles of aloha silicon carbide has improved properties, in particular in the extent and nature of deformation and microcracking around indentations. For example in 500g load knoop indentation tests cracking was much more localised and damage far less extensive. Also there is a greater dependence of hardness on load and may be higher hardness at low loads. These results indicate that bodies in accordance with the invention will behave in general in a more plastic manner have less tendency to crack catastrophically and show greater wear resistance and surface toughness.
The coherent mixture of silicon carbide and carbon may be formed prior to siliconising by any convenient method such as extrusion, injection moulding, slipcasting or pressing.
The fine silicon carbide particles in beta form are preferably produced by passing silicon monoxide through a bed of particulate carbon which is converted to silicon carbide powder, the silicon monoxide vapour being generated by heating a mixture of silica and silicon separately from the bed of particulate carbon.
The following are examples of ways of carrying the invention into effect. Example 1.
A mix containing carbon and beta-silicon carbide powders in the ratio 0.5:1 by weight, and sufficient polymeric binder to provide 42% porosity in the fully-consolidated body on removal of the binder, was formed into a cylincrical pellet by pressing at about 50 MN/rn with the exclusion of air. The silicon carbide powder had a surface area of 3.7 m2/g and the carbon powder consisted of crystallites which formed agglomerates with a surface area of about 6 m2/g. The pellet was extruded through a profiled die to form components of uniform cross-section and the extrudate was cut and heated to 400°C to volatilise the binder. The 'green' material was then fired at 1550ºC in the presence of molten silicon to convert it to a 90% dense silicon carbide containing 10% free silicon. Example 2 A mix containing carbon and beta-silicon carbide powders of the same size as in Example 1 but in the ratio 0.25:1 by weight, and sufficient polymeric binder to form a hard rigid body on compaction, was pressed isostatically at about 100 MN/m2 to form a component which was subsequently 'green machined', using a diamond tool. The 'green' material was heated to 400°C to volatilise the binder an was then fired at 1650°C in the presence of molten silicon to convert it to a 90% dense silicon carbide containing free silicon. Example 3
Beta silicon carbide powder, surface area 2 m 2/g, was mixed with carbon black, surface area 5 m /g, in the ratio 1:0.4 by weight. An aqueous slip was made up and a slip-cast slab was made. The slab was dried and siliconised at 1650ºC for 2 hours in a vacuum of 1 torr. After cooling excess silicon was removed from the surface by abrasive blasting and the density of the slab was found to be 3.04g/cm3 that is, it contained 19% by volume free silicon. The mean grain size in the slab was approximately 0.7 micro
Example 4 Beta silicon carbide powder, surface area 4.4 m2/g vss mixed with carbon black, surface area 6 m2/g, in the ratio of 1:0.3.
A slab was formed as in Example 3 and siliconised at 1600ºC for 30 minutes. The density was 2.92 g/cm3 (33% by volume free silicon) and the mean grain size was 0.5 microns.
Example 5 A beta silicon carbide powder, surface area 0.8 m2/g was mixed with graphite powder, surface area 60 m /g in the ratio 1:0.4 by weight. Binder and lubricants were mixed in and rods 4 mm in diameter were extruded. After removal of the binder the rods were siliconised at 1650°C for 2 hours in a vacuum of 1 torr. Density of the rod was 3.12 g/
(10% by volume free silicon) the meangrain size was about
5 microns and the Knoop hardness at 50g load was 3,650 hg/mm2

Claims

1. A self-bonded silicon carbide body produced by siliconising a preformed mixture of particles of carbon and silicon carbide wherein the silicon carbide in the preforme mixture is in the beta form and the silicon carbide in the self-bonded silicon carbide body has a mean grain size in the range 0.1-5 microns.
2. A method of producing a self-bonded silicon carbide body by siliconising a preformed mixture of particles of carbon and silicon carbide in the beta form, the silicon carbide particles having a mean surface area in the range of 0.5-20 square metres per gram,
3. A method of producing a self-bonded silicon carbide body as claimed in claim 2 wherein the silicon carbide particles have a mean surface area less than 5 square. metres per gram.
4. A method of producing a self-bonded silicon carbide body as claimed in claim 2 or claim 3 wherein the silicon carbide particles in the mixture are produced by passing through a bed of particulate carbon silicon monoxide vapour generated separately by heating a mixture of silicon and silica.
PCT/GB1980/000182 1980-10-27 1980-10-27 Silicon carbide bodies WO1982001545A1 (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
EP80901959A EP0063112A1 (en) 1980-10-27 1980-10-27 Silicon carbide bodies
PCT/GB1980/000182 WO1982001545A1 (en) 1980-10-27 1980-10-27 Silicon carbide bodies
JP55502388A JPS57501578A (en) 1980-10-27 1980-10-27
DE803050618A DE3050618A1 (en) 1980-10-27 1980-10-27 Silicon carbide bodies

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
WOGB80/00182801027 1980-10-27
PCT/GB1980/000182 WO1982001545A1 (en) 1980-10-27 1980-10-27 Silicon carbide bodies

Publications (1)

Publication Number Publication Date
WO1982001545A1 true WO1982001545A1 (en) 1982-05-13

Family

ID=10510428

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/GB1980/000182 WO1982001545A1 (en) 1980-10-27 1980-10-27 Silicon carbide bodies

Country Status (4)

Country Link
EP (1) EP0063112A1 (en)
JP (1) JPS57501578A (en)
DE (1) DE3050618A1 (en)
WO (1) WO1982001545A1 (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2528823A1 (en) * 1982-06-18 1983-12-23 Us Energy PROCESS FOR MANUFACTURING CARBON OR GRAPHITE ARTICLES CONTAINING REACTION-LINKED SILICON CARBIDE
DE19708249A1 (en) * 1996-03-01 1997-09-04 Ngk Insulators Ltd Sintered material based on silicon@ and silicon carbide
US6609452B1 (en) 2000-01-11 2003-08-26 M Cubed Technologies, Inc. Silicon carbide armor bodies, and methods for making same
US7104177B1 (en) 2000-01-11 2006-09-12 Aghajanian Michael K Ceramic-rich composite armor, and methods for making same
WO2008061521A2 (en) 2006-11-23 2008-05-29 Universität Paderborn Method for producing an object at least partly with a silicon carbide structure from a blank of a carbon-containing material
EP2297033A1 (en) * 2008-05-21 2011-03-23 Dalian Institute Of Chemical Physics, Chinese Academy of Sciences Process for producing silicon carbide

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1180918A (en) * 1966-06-10 1970-02-11 Atomic Energy Authority Uk Improvements in or relating to the Manufacture of Dense Bodies of Silicon Carbide.
US4166841A (en) * 1978-05-03 1979-09-04 Ford Motor Company Method for making pure beta silicon carbide
GB2017667A (en) * 1978-03-15 1979-10-10 Suzuki H Silicon carbide powder and a process for producing such powder
US4195049A (en) * 1978-07-13 1980-03-25 Ford Motor Company Method of increasing the strength of a beta silicon carbide article

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1478898A (en) * 1973-10-24 1977-07-06 Gen Electric Silicon carbide ceramic
JPS5924754B2 (en) * 1977-07-07 1984-06-12 信越化学工業株式会社 Method for manufacturing silicon carbide molded body

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1180918A (en) * 1966-06-10 1970-02-11 Atomic Energy Authority Uk Improvements in or relating to the Manufacture of Dense Bodies of Silicon Carbide.
GB2017667A (en) * 1978-03-15 1979-10-10 Suzuki H Silicon carbide powder and a process for producing such powder
US4166841A (en) * 1978-05-03 1979-09-04 Ford Motor Company Method for making pure beta silicon carbide
US4195049A (en) * 1978-07-13 1980-03-25 Ford Motor Company Method of increasing the strength of a beta silicon carbide article

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
CHEMICAL ABSTRACTS, Volume 88, No. 12, issued 1978, March 20 (Columbus, Ohio, US), see page 249, column 1, the Abstract No. 78029c, SU, A, 585142, 25th December 1977, Podmoskovnyi Mining-Chemical Plant *

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2528823A1 (en) * 1982-06-18 1983-12-23 Us Energy PROCESS FOR MANUFACTURING CARBON OR GRAPHITE ARTICLES CONTAINING REACTION-LINKED SILICON CARBIDE
DE19708249A1 (en) * 1996-03-01 1997-09-04 Ngk Insulators Ltd Sintered material based on silicon@ and silicon carbide
US5851941A (en) * 1996-03-01 1998-12-22 Ngk Insulators, Ltd. Si/SiC-based sintered material having excellent corrosion resistance and kiln furniture
DE19708249C2 (en) * 1996-03-01 2002-03-21 Ngk Insulators Ltd Si / SiC based sintered material with excellent corrosion resistance and its uses
US6609452B1 (en) 2000-01-11 2003-08-26 M Cubed Technologies, Inc. Silicon carbide armor bodies, and methods for making same
US6805034B1 (en) 2000-01-11 2004-10-19 M Cubed Technologies, Inc. Silicon carbide armor bodies, and methods for making same
US7104177B1 (en) 2000-01-11 2006-09-12 Aghajanian Michael K Ceramic-rich composite armor, and methods for making same
WO2008061521A2 (en) 2006-11-23 2008-05-29 Universität Paderborn Method for producing an object at least partly with a silicon carbide structure from a blank of a carbon-containing material
WO2008061521A3 (en) * 2006-11-23 2008-07-10 Univ Paderborn Method for producing an object at least partly with a silicon carbide structure from a blank of a carbon-containing material
US8168116B2 (en) 2006-11-23 2012-05-01 Universitaet Paderborn Method for producing an object at least partly with a silicon carbide structure from a blank of a carbon-containing material
EP2297033A1 (en) * 2008-05-21 2011-03-23 Dalian Institute Of Chemical Physics, Chinese Academy of Sciences Process for producing silicon carbide
EP2297033A4 (en) * 2008-05-21 2012-07-04 Dalian Chemical Physics Inst Process for producing silicon carbide

Also Published As

Publication number Publication date
EP0063112A1 (en) 1982-10-27
JPS57501578A (en) 1982-09-02
DE3050618A1 (en) 1982-11-18

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