CA2441576A1 - Ceramic materials in powder form and method for their preparation - Google Patents

Ceramic materials in powder form and method for their preparation Download PDF

Info

Publication number
CA2441576A1
CA2441576A1 CA002441576A CA2441576A CA2441576A1 CA 2441576 A1 CA2441576 A1 CA 2441576A1 CA 002441576 A CA002441576 A CA 002441576A CA 2441576 A CA2441576 A CA 2441576A CA 2441576 A1 CA2441576 A1 CA 2441576A1
Authority
CA
Canada
Prior art keywords
process according
ceramic material
powder form
group
silicon
Prior art date
Legal status (The legal status 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 status listed.)
Abandoned
Application number
CA002441576A
Other languages
French (fr)
Inventor
Sabin Boily
Pascal Tessier
Houshang Alamdari
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
GROUPE MINUTIA Inc
Original Assignee
Individual
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
Priority claimed from CA002331470A external-priority patent/CA2331470A1/en
Application filed by Individual filed Critical Individual
Priority to CA002441576A priority Critical patent/CA2441576A1/en
Publication of CA2441576A1 publication Critical patent/CA2441576A1/en
Abandoned legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B21/00—Nitrogen; Compounds thereof
    • C01B21/082—Compounds containing nitrogen and non-metals and optionally metals
    • C01B21/0821—Oxynitrides of metals, boron or silicon
    • C01B21/0826—Silicon aluminium oxynitrides, i.e. sialons
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B21/00—Nitrogen; Compounds thereof
    • C01B21/06—Binary compounds of nitrogen with metals, with silicon, or with boron, or with carbon, i.e. nitrides; Compounds of nitrogen with more than one metal, silicon or boron
    • C01B21/0602—Binary compounds of nitrogen with metals, with silicon, or with boron, or with carbon, i.e. nitrides; Compounds of nitrogen with more than one metal, silicon or boron with two or more other elements chosen from metals, silicon or boron
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B21/00—Nitrogen; Compounds thereof
    • C01B21/082—Compounds containing nitrogen and non-metals and optionally metals
    • C01B21/0821—Oxynitrides of metals, boron or silicon
    • C01B21/0823—Silicon oxynitrides
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B21/00—Nitrogen; Compounds thereof
    • C01B21/082—Compounds containing nitrogen and non-metals and optionally metals
    • C01B21/0821—Oxynitrides of metals, boron or silicon
    • C01B21/0825—Aluminium oxynitrides
    • 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
    • C04B35/58—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 borides, nitrides, i.e. nitrides, oxynitrides, carbonitrides or oxycarbonitrides or silicides
    • C04B35/597—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 borides, nitrides, i.e. nitrides, oxynitrides, carbonitrides or oxycarbonitrides or silicides based on silicon oxynitride, e.g. SIALONS
    • 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
    • C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/626—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B
    • C04B35/62605—Treating the starting powders individually or as mixtures
    • C04B35/6261—Milling
    • 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
    • C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/626—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B
    • C04B35/62605—Treating the starting powders individually or as mixtures
    • C04B35/6261—Milling
    • C04B35/62615—High energy or reactive ball milling
    • 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
    • C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/626—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B
    • C04B35/62605—Treating the starting powders individually or as mixtures
    • C04B35/62625—Wet mixtures
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2002/00—Crystal-structural characteristics
    • C01P2002/60—Compounds characterised by their crystallite size
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00—Particle morphology
    • C01P2004/50—Agglomerated particles
    • 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
    • C01P2004/61—Micrometer sized, i.e. from 1-100 micrometer
    • 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
    • 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
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
    • C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
    • C04B2235/3217—Aluminum oxide or oxide forming salts thereof, e.g. bauxite, alpha-alumina
    • 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
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
    • C04B2235/34—Non-metal oxides, non-metal mixed oxides, or salts thereof that form the non-metal oxides upon heating, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
    • C04B2235/3418—Silicon oxide, silicic acids, or oxide forming salts thereof, e.g. silica sol, fused silica, silica fume, cristobalite, quartz or flint
    • 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
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
    • C04B2235/38—Non-oxide ceramic constituents or additives
    • C04B2235/3852—Nitrides, e.g. oxynitrides, carbonitrides, oxycarbonitrides, lithium nitride, magnesium nitride
    • C04B2235/3865—Aluminium nitrides
    • 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
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
    • C04B2235/38—Non-oxide ceramic constituents or additives
    • C04B2235/3852—Nitrides, e.g. oxynitrides, carbonitrides, oxycarbonitrides, lithium nitride, magnesium nitride
    • C04B2235/3865—Aluminium nitrides
    • C04B2235/3869—Aluminium oxynitrides, e.g. AlON, sialon
    • 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
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
    • C04B2235/38—Non-oxide ceramic constituents or additives
    • C04B2235/3852—Nitrides, e.g. oxynitrides, carbonitrides, oxycarbonitrides, lithium nitride, magnesium nitride
    • C04B2235/3873—Silicon nitrides, e.g. silicon carbonitride, silicon oxynitride
    • 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
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
    • C04B2235/42—Non metallic elements added as constituents or additives, e.g. sulfur, phosphor, selenium or tellurium
    • C04B2235/421—Boron
    • 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
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
    • C04B2235/42—Non metallic elements added as constituents or additives, e.g. sulfur, phosphor, selenium or tellurium
    • C04B2235/428—Silicon
    • 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
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/50—Constituents or additives of the starting mixture chosen for their shape or used because of their shape or their physical appearance
    • C04B2235/54—Particle size related information
    • C04B2235/5418—Particle size related information expressed by the size of the particles or aggregates thereof
    • C04B2235/5436—Particle size related information expressed by the size of the particles or aggregates thereof micrometer sized, i.e. from 1 to 100 micron
    • 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
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/50—Constituents or additives of the starting mixture chosen for their shape or used because of their shape or their physical appearance
    • C04B2235/54—Particle size related information
    • C04B2235/5418—Particle size related information expressed by the size of the particles or aggregates thereof
    • C04B2235/5445—Particle size related information expressed by the size of the particles or aggregates thereof submicron sized, i.e. from 0,1 to 1 micron
    • 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
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/50—Constituents or additives of the starting mixture chosen for their shape or used because of their shape or their physical appearance
    • C04B2235/54—Particle size related information
    • C04B2235/5418—Particle size related information expressed by the size of the particles or aggregates thereof
    • C04B2235/5454—Particle size related information expressed by the size of the particles or aggregates thereof nanometer sized, i.e. below 100 nm
    • 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
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/50—Constituents or additives of the starting mixture chosen for their shape or used because of their shape or their physical appearance
    • C04B2235/54—Particle size related information
    • C04B2235/549—Particle size related information the particle size being expressed by crystallite size or primary particle size
    • 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
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/70—Aspects relating to sintered or melt-casted ceramic products
    • C04B2235/96—Properties of ceramic products, e.g. mechanical properties such as strength, toughness, wear resistance
    • C04B2235/9607—Thermal properties, e.g. thermal expansion coefficient

Abstract

The invention relates to a ceramic material in powder form comprising particles having an average particle size of 0.1 to 30 µm and each formed of an agglomerate of grains with each grain comprising a nanocrystal of a ceramic material of formula (I): Si3-xAlxOyNz, wherein 0 <= x <= 3, 0 <= y <=
6 and 0 <= z <= 4, with the proviso that when x is 0 or 3, y cannot be 0. The ceramic material in powder form according to the invention is suitable for use in the production of ceramic bodies by powder metallurgy, as well as in the formation of heat-resistant coatings by thermal deposition. The ceramic bodies and coatings obtained have improved resistance to thermal shocks.

Description

CERAMIC MATERIALS IN POWDER FORM
Technical Field The present invention pertains to improvements in the field of ceramic materials. More particularly, the invention relates to ceramic materials in powder form for use in the formation of ceramic bodies and coatings having improved mechanical properties.
Background Art All current methods of producing dense silicon and/or aluminum-based ceramic bodies are variations of a process wherein a mixture of powders is compacted and sintered at high temperature.
Densification is usually achieved through the use of sintering aids which lead to the formation of a liquid phase between powder particles, thus ensuring densification. However, this usually weakens the material, since the liquid phase forms upon solidification a vitreous or crystalline phase having poor mechanical properties.
The current methods also produce coarse grains having typical dimensions of several microns, caused by the necessity to react raw materials and densify the ceramics at high temperatures. These coarse grains are detrimental to mechanical properties such as resistance to thermal shocks.
Disclosure of the Invention It is therefore an object of the present invention to overcome the above drawback and to provide a ceramic material in powder form suitable for use in forming ceramic bodies and coatings having improved mechanical properties and, more particularly, improved resistance to thermal shocks.
According to one aspect of the invention, there is provided a ceramic material in powder form comprising particles having an average particle size of 0.1 to 30 ~m and each formed of an agglomerate of grains with each grain comprising a nanocrystal of a ceramic material of the formula:
Si3_XAIXOyNZ (1) wherein 0 5 x <_ 3, 0 <_ y 5 6 and 0 < z <_ 4, with the proviso that when x is or 3, y cannot be 0.
The term "nanocrystal" as used herein refers to a crystal having a size of 100 nanometers or less. The nanocrystalline microstructure considerably favors densification, even without sintering aids, when the ceramic material in powder form according to the invention is compacted and sintered to produce dense ceramic bodies. Nanocrystalline powders also minimize grain growth.
The present invention also provides, in another aspect thereof, a process for producing a ceramic material in powder form as defined above.
The process of the invention comprises the steps of a) providing at least two reagents comprising as a whole at least three elements selected from the group consisting of silicon, aluminum, oxygen and nitrogen; and b) subjecting the reagents to high-energy ball milling to cause solid state reaction therebetween and formation of particles having an average particle size of 0.1 to 30 ~,m, each particle being formed of an agglomerate of grains with each grain comprising a nanocrystal of a ceramic material of formula (I) defined above.
The expression "high-energy ball milling" as used herein refers to a ball milling process capable of forming the aforesaid particles comprising nanocrystalline grains of the ceramic material of formula (I), within a period of time of about 40 hours.
Modes for Carr' n~ out the Invention Examples of ceramic material of the formule (I) include Si2.$Alo.z~o.3N3.~ and Sil.sAh.sOa.sNi.s~
Examples of suitable reagents which may be used in the process according to the invention include silicon, aluminum, aluminum silicide as well as oxides, nitrides and oxynitrides of silicon and/or aluminum. Si, Si02, Si3N4, Al, A1203 and A1N are particularly preferred.
According to a preferred embodiment, step (b) is carried out in a vibratory ball mill operated at a frequency of 8 to 25 Hz, preferably about 17 Hz. It is also possible to conduct step (b) in a rotary ball mill operated at a speed of 150 to 1500 r.p.m., preferably about 1000 r.p.m.
According to another preferred embodiment, step (b) is carried out under an inert gas atmosphere such as a gas atmosphere comprising argon or helium, or under a reactive gas atmosphere such as a gas atmosphere comprising hydrogen, nitrogen, ammonia, carbon monoxide, carbon dioxide, silicon tetrahydride, silicon tetrachloride or water vapor. An atmosphere of argon, helium or hydrogen is preferred. It is also possible to carry our step (b) in the presence of a liquid such as a hydrocarbon (e.g.
butane), acetone, methanol, ethanol, isopropanol, toluene or water, or a greasy substance such as stearic acid, to prevent the particles from adhering to one another.
Additives can be added during step (b) in order to improve the mechanical properties (e.g. flexural strength and hardness) of the ceramic bodies and/or coatings eventually made from the ceramics powder of the invention, to reduce their wettability by molten metals or alloys andlor to reduce their chemical reactivity (e.g. oxidation) with the environment.
Examples of suitable additives include those comprising at least one element selected from the group consisting of B, C, Mg, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Se, Rb, Sr, Y, Zr, Nb, Mo, Rh, Cd, Te, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Icy, Ho, Er, Tm, Yb, Lu, Hf, Ta, Os, Ir and Tl. Boron and carbon are preferred.
The ceramic material in powder form according to the invention can be used to produce dense bodies by powder metallurgy. The expression "powder metallurgy" as used herein refers to a technique in which the bulk powders are transformed into preforms of a desired shape by compaction or shaping followed by a sintering step. Compaction refers to techniques where pressure is applied to the powder, as, for example, cold uniaxial pressing, cold isostatic pressing or hot isostatic pressing. Shaping refers to techniques executed without the application of external pressure such as powder filling or slurry casting. The dense bodies thus obtained can be used as structural parts, electronic substrates and other ceramic products.
The ceramic material in powder form according to the invention can also be used in thermal deposition applications. The expression "thermal deposition" as used herein refers to a technique in which powder particles are injected in a torch and sprayed on a substrate to form thereon a heat-resistant coating. The particles acquire a high velocity and are partially or totally melted during the flight path. The coating is built by the solidification of the droplets on the substrate surface. Examples of such techniques include plasma spray, arc spray and high velocity oxy-fuel.
The following non-limiting examples illustrate the invention.

A Si2,8A1o.20o.3N3.7 powder was produced by ball milling 3.71 g of Si3N4 and 0.298 of A1203 in a tungsten carbide crucible with a ball-to-powder mass ratio of ~.1 using a SPEX X000 (trademark) vibratory ball mill operated at a frequency of about 17 Hz. The operation was performed under a controlled argon atmosphere. The crucible was closed and sealed with a rubber O-ring. After 20 hours of high-energy ball milling, a Sy,8A10,20o.3N3.7 nanocrystalline structure was formed. The particle size varied between 0.1 and 5 ~m and the crystallite size, measured by X-ray diffraction, was about 30 nm. The ceramic powder thus obtained was sintered without sintering aids to produce a dense body having improved resistance to thermal shocks.

A Sil,sAll.sOa.sNi.s powder was produced by ball milling 0.5238 of Si02, O.OSg of Si and 0.42~g of A1N in a silicon nitride vial with two 1/2 inch silicon nitride balls. The vial was sealed and placed in a SPEX
X000 vibratory ball mill operated at 17 Hz for 20 hours. The ceramic powder thus obtained was sintered without using any additive to produce a dense body.

A Si2,8Alo,a0o.3N3.7 powder was produced by ball milling 1:855g of Si3N4 and 0.145g of A1a03 in a silicon nitride vial with two 1/a inch silicon nitride balls. O.OSg of boron was added to the mixture prior to milling. The vial was sealed and placed in a SPEX 8000 vibratory ball mill operated at 17 Hz for 20 hours. The ceramic powder thus obtained was sintered to produce a dense body that showed improved thermal shock resistance.

Claims (23)

Claims
1. A ceramic material in powder form comprising particles having an average particle size of 0.1 to 30 µm and each formed of an agglomerate of grains with each grain comprising a nanocrystal of a ceramic material of the formula:

Si3-x Al x O y N z~(I') wherein 0 < x < 3, 0 < y <= 6 and 0 < z <= 4, and wherein ceramic materials of formula (I) in which x = y and z - 4 - x are excluded.
2. A ceramic material in powder form according to claim 1, wherein x is 0.2, y is 0.3 and z is 3.7.
3. A ceramic material in powder form according to claim 1, wherein x is 1.5, y is 2.5 and z is 1.5.
4. A ceramic material in powder form according to claim 1, further including at least one additive comprising at least one element selected from the group consisting of B, C, Mg, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Se, Rb, Sr, Y, Zr, No, Mo, Rh, Cd, Te, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Hb, Er, Tm, Yb, Lu, Hf, Ta, Os, Ir and Tl.
5. A ceramic material in powder form according to claim 4, wherein said additive is boron or carbon.
6. A ceramic material in powder form according to claim 1, wherein said average particle size ranges from 0.1 to 5 µm.
7. A process for producing a ceramic material in powder form comprising particles having an average particle size of 0.1 to 30 µm and each formed of an agglomerate of grains with each grain comprising a nanocrystal of a ceramic material of the formula Si3-x Al x O y N z (I) wherein 0 <= x <= 3, 0 <= y <= 6 and 0 < z <= 4, with the proviso that when x is 0 or 3, y cannot be 0, the process comprising the steps of:
a) providing at least two reagents comprising as a whole at least three elements selected from the group consisting of silicon, aluminum, oxygen and nitrogen; and b)subjecting said reagents to high-energy ball milling to cause solid state reaction therebetween and formation of particles having an average particle size of 0.1 to 30 µm, each particle being formed of an agglomerate of grains with each grain comprising a nanocrystal of a ceramic material of the formula (I).
8. A process according to claim 7, wherein said reagents are selected from the group consisting of silicon, aluminum silicide and oxides, nitrides and oxynitrides of silicon and aluminum.
9. A process according to claim 8, wherein said reagents are selected from the group consisting of Si, SiO2, Si3N4, Al, Al2O3 and AlN.
10. A process according to claim 7, wherein step (b) is carried out in a vibratory ball mill operated at a frequency of 8 to 25 Hz.
11. A process according to claim 10 wherein said vibratory ball mill is operated at a frequency of about 17 Hz.
12. A process according to claim 7, wherein step (b) is carried out in a rotary ball mill operated at a speed of 150 to 1500 r.p.m.
13. A process according to claim 12, wherein said rotary ball mill is operated at a speed of about 1000 r.p.m.
14. A process according to claim 7, wherein step (b) is carried out under an inert gas atmosphere.
15. A process according to claim 14, wherein said inert gas atmosphere comprises argon or helium.
16. A process according to claim 7, wherein step (b) is carried out under a reactive gas atmosphere.
17. A process according to claim 16, wherein said reactive gas atmosphere comprises hydrogen, nitrogen, ammonia, carbon, monoxide, carbon dioxide, silicon tetrahydride, silicon tetrachloride or water vapor.
18. A process according to claim 17, wherein step (b) is carried out in the presence of a liquid or a greasy substance.
19. A process according to claim 18, wherein said liquid is selected from the group consisting of butane, acetone, methanol, ethanol, isopropanol, toluene and water.
20. A process according to claim 18, wherein said greasy substance is stearic acid.
21. A process according to claim 7, further including the step of admixing during step (b) at least one additive comprising at least one element selected from the group consisting of B, C, Mg, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zu, Se, Rb, Sr, Y Zr, Nb, Mo, Rh, Cd, Te, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, Os, Ir and Tl.
22. A process according to claim 21, wherein said additive is boron.
23. A process according to claim 21, wherein said additive is carbon.
CA002441576A 2001-01-19 2002-01-18 Ceramic materials in powder form and method for their preparation Abandoned CA2441576A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CA002441576A CA2441576A1 (en) 2001-01-19 2002-01-18 Ceramic materials in powder form and method for their preparation

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
CA2,331,470 2001-01-19
CA002331470A CA2331470A1 (en) 2001-01-19 2001-01-19 Ceramic materials in powder form
PCT/CA2002/000070 WO2002057182A2 (en) 2001-01-19 2002-01-18 Ceramic materials in powder form and method for their preparation
CA002441576A CA2441576A1 (en) 2001-01-19 2002-01-18 Ceramic materials in powder form and method for their preparation

Publications (1)

Publication Number Publication Date
CA2441576A1 true CA2441576A1 (en) 2002-07-25

Family

ID=30001269

Family Applications (1)

Application Number Title Priority Date Filing Date
CA002441576A Abandoned CA2441576A1 (en) 2001-01-19 2002-01-18 Ceramic materials in powder form and method for their preparation

Country Status (1)

Country Link
CA (1) CA2441576A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2997419A1 (en) * 2012-10-31 2014-05-02 Saint Gobain Ct Recherches CREUSET INCORPORATING A SIALON COATING.

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2997419A1 (en) * 2012-10-31 2014-05-02 Saint Gobain Ct Recherches CREUSET INCORPORATING A SIALON COATING.
WO2014068230A1 (en) * 2012-10-31 2014-05-08 Saint-Gobain Centre De Recherches Et D'etudes Europeen Crucible incorporating a sialon coating

Similar Documents

Publication Publication Date Title
Kear et al. Chemical processing and applications for nanostructured materials
US5214011A (en) Process for preparing ceramic-metal composite bodies
EP2165990B1 (en) Dense boron carbide ceramic and process for producing the same
WO1998022244A1 (en) Process for making a dense ceramic workpiece
US20040067837A1 (en) Ceramic materials in powder form
KR20110136788A (en) Ultra hard/hard composite materials
WO2018110565A1 (en) Method for producing high-purity silicon nitride powder
US5640666A (en) Composite silicide/silicon carbide mechanical alloy
Creber et al. AIN composite growth by nitridation of aluminum alloys
Kijima et al. Sintering of ultrafine SiC powders prepared by plasma CVD
EP4215479A1 (en) Cubic boron nitride powder and manufacturing method therefor
JPS6131358A (en) Silicon nitride sintered body for cutting tool and manufacture
US5234643A (en) Silicon nitride ceramics containing crystallized grain boundary phases
JP2967094B2 (en) Aluminum nitride sintered body and method for producing aluminum nitride powder
Cliche et al. Synthesis of TiC and (Ti, W) C in solvent metals
CA2441576A1 (en) Ceramic materials in powder form and method for their preparation
Merzhanov et al. Self-propagating high-temperature synthesis of carbides, nitrides, and borides
JPS6210954B2 (en)
JPS629548B2 (en)
Ma et al. Synthesis mechanism of AlN–SiC solid solution reinforced Al2O3 composite by two-step nitriding of Al–Si3N4–Al2O3 compact at 1500° C
KR100714978B1 (en) The method for fabricatiing ultrafine crystalline TiN/TiB2 composite cermet
Sodeoka et al. Structure and properties of plasma-sprayed SiAlON coatings
JP3023435B2 (en) High purity silicon carbide sintered body and method for producing the same
JPH11139882A (en) Composite silicon nitride powder and its production
JP2000144301A (en) Tungsten carbide sintered body and its production

Legal Events

Date Code Title Description
FZDE Discontinued