[go: up one dir, main page]

WO1989003371A1 - Traiteement en une etape de frittage/pressage isostatique a chaud de matiere ceramique - Google Patents

Traiteement en une etape de frittage/pressage isostatique a chaud de matiere ceramique Download PDF

Info

Publication number
WO1989003371A1
WO1989003371A1 PCT/US1987/002597 US8702597W WO8903371A1 WO 1989003371 A1 WO1989003371 A1 WO 1989003371A1 US 8702597 W US8702597 W US 8702597W WO 8903371 A1 WO8903371 A1 WO 8903371A1
Authority
WO
WIPO (PCT)
Prior art keywords
compact
hip
sinter
accordance
pressure
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.)
Ceased
Application number
PCT/US1987/002597
Other languages
English (en)
Inventor
Andrew C. Nyce
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.)
GORHAM ADVANCED MATERIALS INSTITUTE
Original Assignee
GORHAM ADVANCED MATERIALS INSTITUTE
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 GORHAM ADVANCED MATERIALS INSTITUTE filed Critical GORHAM ADVANCED MATERIALS INSTITUTE
Priority to PCT/US1987/002597 priority Critical patent/WO1989003371A1/fr
Publication of WO1989003371A1 publication Critical patent/WO1989003371A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

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
    • C04B35/58—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
    • C04B35/584—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 nitride
    • C04B35/593—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 nitride obtained by pressure sintering
    • 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
    • C04B35/64—Burning or sintering processes
    • C04B35/645—Pressure sintering
    • C04B35/6455—Hot isostatic pressing

Definitions

  • the present invention relates to the field of Hot Isostatic Pressing ("HIP") processing of ceramic materials and is characterized by affording combined benefits of elimination of microporosity in the finished products achieved at relatively low cost for such performance enhancement.
  • HIP Hot Isostatic Pressing
  • the present invention is applicable to overcoming the foregoing problems in connection with various ceramics including aluminas, zirconias, (both silicon and aluminum) nitrides e.g., Si 3 N 4 , as well as SiAlON's, silicon carbides, zirconium borides, tungsten and titanium carbides, titanium nitride, and combinations of these internally within the above group and with other ceramic or metal additives and reinforcements such as high strength ceramic whiskers and fibers and ceramic particulates.
  • the foregoing object and subsidiary objects of applying the same benefit on a material class by class basis are realized in accordance with the present invention.
  • the invention utilizes a one thermal cycle approach in which green, uncontainerized parts of assembled ceramic powder compacts of net shape or near net shape are placed in a hot isostatic press. This is done after a de-bindering step which removes any binder material from the compact.
  • Prepress processing of the compact may comprise a cold isostatic press step as part of assembling and consolidating.
  • the compacts are sintered in the hot isostatic press to close up any surface-connected porosity within a few tenths of an inch of the surface and to pre-react sinter-aiding additives, if any within the compact, prior to the ultimate sintering.
  • Sintering This term is to be construed as denoting a high temperature densification process conducted under low to moderate gas pressure (generally N2 for Si3N4 and SiAlON ceramics) .
  • gas pressure generally N2 for Si3N4 and SiAlON ceramics
  • the terms "sintering” and “low press ure sintering” as used herein indicate high temperature densification processing of green powder compacts conducted at between 1-20 atmospheres N 2 . under such conditions the function of the gas is primarily to reduce net dissociation of S13N4 and thereby enhance densification.
  • This mode of sintering includes, then, the sorts of processing often referred to in the open research literature as “pressureless sintering” or "overpressure sintering".
  • Th term "high pressure sintering”, is reserved to connote sintering of green compacts under higher N 2 pressures, e.g., up to 100 or more atmospheres.
  • the function of the gas pressure in such cases is, theoretically, two fold: to reduce Si 3 N 4 dissociation and to modify the sintering kinetics of the test materials by chemically altering their phase composition at elevated temperature and by causing a pressure induced change in liquid phases present in the system.
  • SiAlON and AI 2 O 3 other ceramic production is enhanced through the present invention through the use of high reactive gas pressure to enhance sintering kinetics of these material systems.
  • Hot Pressing This term means uniaxial hot pressing, where the compressive force is generally mediated through a hydraulically driven ram.
  • This mode of ceramic powder compaction is also referred to in the research literature as "pressure sintering".
  • pressure sintering As noted above high pressure sintering and low pressure sintering in context of this application designate elevated temperature densification processes conducted under gas pressure.
  • HIP' ing This term denotes the simultaneous application of elevated temperatures and high isostatic gas pressure, used to densify materials. Pressures in the 15,000-30,000 psi range are typically used in HIP'ing (also known as clad HIP'ing or canned HIP'ing) of Si 3 N 4 and SiAlON ceramics involves enclosing powders or preforms within hermetically sealed, gas tight containers made of refractory metals or glasses. The compressive forces exerted by the high pressure gas during processing are transmitted through the container to the enclosed powder or part, while the gas itself is prevented from entering (and equilibrating within the pores of the enclosed material , which would preclude pressing) .
  • Containerless HIP'ing requires high density, closed porosity parts. Such parts are themselves gas tight; thus the need for enclosing them within sealed, refractory metal or glass gas-barriers is eliminated.
  • Containerless HIP'ing encompasses two different processing approaches designated Sinter + HIP and Sinter/HIP.
  • Sinter + HIP is a mode of containerless HIP' ing employing discrete sintering and HIP'ing processing cycles.
  • green compacts are sintered to high density and closed porosity in a sintering furnace (as used in "pressureless” or “over pressure” sintering) .
  • the parts are introduced into a hot isostatic press and then run through a complete HIP processing cycle.
  • Sinter/HIP is a mode of containerless HIP'ing in which sintering and HIP'ing are combined into a single, continuous processing cycle.
  • green compacts are sintered under lowto-moderate gas pressure to high density and closed porosity in the initial phase of the overall cycle; following completion of this initial phase of this process, the system is rapidly pressurized to a suitable HIP pressure, while high temperature is maintained, and the sintered specimens are
  • open porosity greenbodies can be both sinter/HIP'ed or high pressure reactive gas sintered depending upon whether the porosity is open or closed when high pressure gas is admitted to the system.
  • AI 2 O 3 was reactive sintered at 1000 psi and at 15 ,000 psi to densities normally not attained under ambient sintering conditions.
  • FIGS. 1 - 5 are graphical representations of ceramic, processing data illustrating the fine distinction between processing within and outside preferred embodiments of the present invention.
  • FIGS. 6 and 7 are flow charts of steps for practice of the process of the invention in accordance with preferred embodiments thereof.
  • FIGS. 1 - 5 shows overlayed pressuretime/termperature-time curves, FIG. 1 illustrating prior art and FIGS. 2 - 4 illustrating preferred examples practice of the present invention in a typi cal case and FIG. 5 illustrating a less preferred embodiments.
  • One or more ceramic powder compacts are placed in a HIP furnace with heating elements and controllable press urization/depressurization means.
  • the furnace is operated to attain a sintering temperature of the compacts (i.e. , to ove r 1000° C) .
  • a sintering temperature of the compacts i.e. , to ove r 1000° C
  • Such high temperature and pressure are held for one one half to several hours; then both are released to ambient conditions.
  • the FIGS. 1 and 5 profiles are more typical of a HIP cycle per se, resulting from initiating HIP too soon in relation to sinter heating.
  • Pressurization should be initiated at any schedule that allows significant sinter bonding or prereaction of additives to precede it.
  • This initial sinter bonding achieves some densification and an essentially closed pore condition of the compact (at least at surface layers thereof) to avoid penetration by pressurized gas during the later onset of HIP processing.
  • the sintering continues under assistance of simultaneous raising of both temperature and external gas pressure to further densify the compact as both temperature and pressure rise.
  • the plateau hold pressure of HIP process during simultaneous sinter is lower than would be required in the absence of concurrent sintering.
  • a liquid or otherwise viscous phase is formed in the initial pre-HIP sintering, at grain boundaries within the compact, as temperature raises and is present as HIP pressure is applied to enhance the effective densification of the compact by such pressure through a combination of classic sinter and HIP densification mechanisms and a unique synergistic effect occurring upon proper sinte r/HI P conditions.
  • FIGS. 2 - 4 processing results in substantially higher final densities of the compact than processing in accordance with FIGS. 1 and 5, and at half the pressure and in less time at high pressure.
  • Graph 4A shows a proposed cycle for high pressure reactive sintering in accordance with the invention.
  • the materials treated in the FIGS. 1 - 5 processing comprised 90-95%:0-3%:6-8% (weight percent mixture of silicon ni tride (Si 3 N 4 ) : yttria (Y 2 O 3 ) : alumina (Al 2 O 3 ) , respectively. Pressures on the order of 15000 psi are applied for the HIP portion of the cycle.
  • the additional ingredient (s) effects appear to include enhancing response of the basic Si 3 N 4 to the sinter HIP/processing conditions.
  • a reactive gas e.g., N 2 as applied to Si3N 4 systems
  • the mixtures are at less than 50% of theoretical density as initially poured into a container and tamped. They are then, slip cast, injection molded, die pressed or cold isostatic pressed to coherent compacts of 55-65% theoretical density. Sinter/HIP processing as described above achieves over 98% of theoretical density of such compacts.
  • FIGS. 1 through 5 The cycles of FIGS. 1 and 5 respectively are conventional HIP cycles which as can be seen from the data were not effective in fully densifying either green or sintered compacts.
  • FIG. 2 cycle resulted in some apparent improvement in the density of previously sintered compacts.
  • Cycles of FIGS. 3 and 4 are particularly effective in achieving near theoretical density for previously sintered compacts of all compositions containing Al 2 O 3 .
  • For green samples subjected to cycles of FIGS. 3 and 4 only those compacts with greater than 3% AI 2 O 3 achieved densities near theoretical.
  • Table II presents data on sinter/HIP densification kinetics of 92-6-2 SiAlONs. Two types of specimen of each 92-6-2 composition were investigated in this kinetics study:
  • FIG. 6 shows in block diagram form the process steps of compacting, heating, sinter/HIPing and release of temperat and pressure. These include more specifically:
  • CIP cold isostatic pressing
  • 60-(initial) sinter i.e., temperature rise in a closed chamber furnace established by radiant heaters facing the containerless compact on a pedestal therein -- to achieve a closed surface, i.e., non-porosity of the surface regions of the compact and further a densification to 90-95% of theoretical indicative of sufficiently advancing sinter to allow the next steps;
  • FIG. 7 shows in block diagram form a variant of the FIG. 6 processing with the same steps 10 - 50 and 80, 90, but with variant steps:
  • the mechanism in this instance emphasized reactions occurring at high pressure under a set of reaction kinetics conditions for more favorable than low pressure.
  • Reactive atmosphere and/or additives in the compact provide the necessary reactive feedstock.
  • the steps 70 or 70 ' of FIG S. 6 and 7. may be useful to induce a thermal spike, a brief increase of the usual S/HIP temperature of about 2000o C held for an hour or so, by at least 20%, e.g. to 2400o for no more than 20% of the plateau hold time (e.g. for 6 - 12 minutes) .
  • This enables effective sinter/HIP of materials that are otherwise insufficiently responsive to the process.
  • the temperature spike condition is easily achieved in the sinter/HIP furnace.
  • the materials treated through such processing may include those noted above and, additionally
  • the ceramics may be in particulate forms ranging from low aspect ratio (near spherical) to high aspect ratios (essentially in whisker fibrous or platelet forms).
  • the invention is preferrably practiced in a single chamber. But elevated temperature and/or pressure processing can be interrupted ty transfer between chambers, provided the drop of temperature or pressure is no more than 5% from the last achieved value.

Landscapes

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

Abstract

Des matières céramiques sont consolidées jusqu'à un niveau proche de la densité théorique en appliquant un procédé en une étape combinée de frittage et de pressage isostatique à chaud (HIP). Ce procédé limite la croissance du grain tout en assurant une consolidation effective à moindre coût.
PCT/US1987/002597 1987-10-08 1987-10-08 Traiteement en une etape de frittage/pressage isostatique a chaud de matiere ceramique Ceased WO1989003371A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/US1987/002597 WO1989003371A1 (fr) 1987-10-08 1987-10-08 Traiteement en une etape de frittage/pressage isostatique a chaud de matiere ceramique

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/US1987/002597 WO1989003371A1 (fr) 1987-10-08 1987-10-08 Traiteement en une etape de frittage/pressage isostatique a chaud de matiere ceramique

Publications (1)

Publication Number Publication Date
WO1989003371A1 true WO1989003371A1 (fr) 1989-04-20

Family

ID=22202601

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1987/002597 Ceased WO1989003371A1 (fr) 1987-10-08 1987-10-08 Traiteement en une etape de frittage/pressage isostatique a chaud de matiere ceramique

Country Status (1)

Country Link
WO (1) WO1989003371A1 (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1999047471A1 (fr) * 1998-03-19 1999-09-23 Biomat System Ab Composition, fabrication et utilisation de nitrure de silicium en tant que materiau biologique a usage medical
CN114195521A (zh) * 2021-12-27 2022-03-18 中国科学院上海硅酸盐研究所 一种热等静压处理氮化硅陶瓷的方法
CN116396081A (zh) * 2023-04-24 2023-07-07 广东工业大学 一种低温烧结制备高强度氮化铝陶瓷的方法
CN118146003A (zh) * 2024-03-19 2024-06-07 上海戎创铠迅特种材料有限公司 一种碳化硅陶瓷零部件及其制备方法

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5771872A (en) * 1980-10-20 1982-05-04 Kobe Steel Ltd Manufacture of high density silicon nitride sintered body
US4379110A (en) * 1979-08-09 1983-04-05 General Electric Company Sintering of silicon nitride to high density

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4379110A (en) * 1979-08-09 1983-04-05 General Electric Company Sintering of silicon nitride to high density
JPS5771872A (en) * 1980-10-20 1982-05-04 Kobe Steel Ltd Manufacture of high density silicon nitride sintered body

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1999047471A1 (fr) * 1998-03-19 1999-09-23 Biomat System Ab Composition, fabrication et utilisation de nitrure de silicium en tant que materiau biologique a usage medical
CN114195521A (zh) * 2021-12-27 2022-03-18 中国科学院上海硅酸盐研究所 一种热等静压处理氮化硅陶瓷的方法
CN114195521B (zh) * 2021-12-27 2022-12-13 中国科学院上海硅酸盐研究所 一种热等静压处理氮化硅陶瓷的方法
CN116396081A (zh) * 2023-04-24 2023-07-07 广东工业大学 一种低温烧结制备高强度氮化铝陶瓷的方法
CN118146003A (zh) * 2024-03-19 2024-06-07 上海戎创铠迅特种材料有限公司 一种碳化硅陶瓷零部件及其制备方法

Similar Documents

Publication Publication Date Title
Greil et al. Sintering and HIPping of silicon nitride-silicon carbide composite materials
US6025065A (en) Production of an aluminide containing ceramic moulding
US4354990A (en) Process for sintering silicon nitride compacts
JPH0710637A (ja) 二酸化ジルコニウム含有セラミック成形体およびその製造方法
Claussen et al. Tailoring of Reaction‐Bonded Al2O3 (RBAO) Ceramics
EP0593474B1 (fr) Cermets composes de b4c/al, et procede de production
US5145833A (en) Method for producing ceramic bodies
US4687655A (en) Process for the manufacture of shaped articles from reaction-bonded silicon nitride by nitridation under elevated nitrogen gas pressure
JPH0714833B2 (ja) 粉末法で製造されたセラミック成形体およびその製造方法
WO1986005480A1 (fr) Corps ceramiques renforces a densite elevee et leur procede de fabrication
US4376742A (en) Fugitive liquid phase densification of silicon nitride
US4542109A (en) Silicon nitride-cordierite ceramic article, and process of manufacture thereof
US4564601A (en) Shaped polycrystalline silicon carbide articles and isostatic hot-pressing process
US5032553A (en) High density high strength alpha sialon based article and process for producing same
WO1989003371A1 (fr) Traiteement en une etape de frittage/pressage isostatique a chaud de matiere ceramique
WO2010008596A1 (fr) Production de corps en céramique tridimensionnels frittés
US4943320A (en) Vapor phase redistribution in multi-component systems
US5194202A (en) Formation of ceramic-metal composite by pressure casting and oxidation sintering
AU8106587A (en) One step sinter/hip processing of ceramics
US5928583A (en) Process for making ceramic bodies having a graded porosity
US5098623A (en) Method for producing ceramic composite materials containing silicon oxynitride and zirconium oxide
German et al. Powder processing of high temperature aluminides
EP0358530B1 (fr) Procédé pour la production de corps céramiques
US4752427A (en) Method for plastic working of ceramics
Davis Hot isostatic pressing

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AU JP

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH DE FR GB IT LU NL SE