US3775043A - Means in furnaces for vacuum-pressure-sintering - Google Patents

Means in furnaces for vacuum-pressure-sintering Download PDF

Info

Publication number
US3775043A
US3775043A US00233925A US3775043DA US3775043A US 3775043 A US3775043 A US 3775043A US 00233925 A US00233925 A US 00233925A US 3775043D A US3775043D A US 3775043DA US 3775043 A US3775043 A US 3775043A
Authority
US
United States
Prior art keywords
combination according
lid
furnace
housing
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.)
Expired - Lifetime
Application number
US00233925A
Other languages
English (en)
Inventor
P Johansson
T Landa
H Larker
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.)
ABB Norden Holding AB
Original Assignee
ASEA AB
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 ASEA AB filed Critical ASEA AB
Application granted granted Critical
Publication of US3775043A publication Critical patent/US3775043A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B30—PRESSES
    • B30B—PRESSES IN GENERAL
    • B30B11/00—Presses specially adapted for forming shaped articles from material in particulate or plastic state, e.g. briquetting presses, tabletting presses
    • B30B11/001—Presses specially adapted for forming shaped articles from material in particulate or plastic state, e.g. briquetting presses, tabletting presses using a flexible element, e.g. diaphragm, urged by fluid pressure; Isostatic presses
    • B30B11/002—Isostatic press chambers; Press stands therefor
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J3/00—Processes of utilising sub-atmospheric or super-atmospheric pressure to effect chemical or physical change of matter; Apparatus therefor
    • B01J3/04—Pressure vessels, e.g. autoclaves
    • B01J3/048—Multiwall, strip or filament wound vessels
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
    • B22F3/12—Both compacting and sintering
    • B22F3/14—Both compacting and sintering simultaneously
    • B22F3/15—Hot isostatic pressing
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
    • F27D3/00—Charging; Discharging; Manipulation of charge
    • F27D3/18—Charging particulate material using a fluid carrier

Definitions

  • a furnace for vacuum-pressure-sintering has a furnace chamber which is enclosed in and insulated from a surrounding pressure Chamber.
  • the pressure chamber includes a bottom projecting into it at the lower end and has at the upper end a charging opening and a lid projecting into the charging opening.
  • a housing can be applied over the charging opening and connected to a vacuum pump during the part of the operating cycle when the pressure in the furnace is to be below atmospheric pressure.
  • the lid is formed of an outer annular part and an inner part, separate from each other, the outer annular part remaining in position when the inner part is removed.
  • a heat radiation protection ring is provided for insertion into the opening into the annular part when the annular part is raised.
  • a lifting device for the lid is provided inside the housing.
  • the present invention relates to an arrangement for .use with a furnace for vacuum-pressure-sintering having a furnace chamber which is enclosed in and insulated from a surrounding pressure chamber composed of a pressure cylinder, a bottom projecting into this cylinder and a lid projecting into the charging opening of the furnace.
  • a method for manufacturing sintered powder bodies having high density which comprises sintering, preferably under vacuum, powder bodies which have been moulded in the conventional manner by compressing powder and then hot-moulding the bodies after the sintering under direct influence of a pressure medium.
  • the sintering of the bodies and the subsequent compression are thus carried out without the bodies being enclosed in a gastight casing.
  • bodies manufactured from a powder'or powder mixture are sintered at atmospheric pressure or lower pressure and at such a temperature that powder particles of the same material are bound together-or that binder binds together other powder particles in the powder mixture, after which the bodies are isostatically hot-moulded in the same furnace under direct influence of a pressure medium such as argon, helium, nitrogen or hydrogen.
  • a pressure medium such as argon, helium, nitrogen or hydrogen.
  • the binder thus forms a closed capsule around each individual space and prevents the pressure medium from penetrating into the body.
  • these cavities disappear in the same way as they do when the hot-moulding is carried out with the material enclosed in a casing when pressure and temperature are chosen so that the binder is sufficiently easily deformed so that powder'particles bound to gether will slide towards each other and fill out the empty cavities.
  • sintered bodies which are manufactured according to. conventional methods usually contain 100 500 times as many cavities per unit of volume as bodies manufactured in accordance with that method.
  • the advantage is gained that a timeconsuming and expensive stage in the production is eliminated.
  • the process makes possible sintering without encasing, without cooling of the bodies between sintering and hot-moulding and without complicated transfer means with sluices to prevent hot bodies from coming into contact with air.
  • U0 a density ofup to 99.5 percent of the theoretically achievable density can be obtained.
  • the furnace is of the type comprising a cylindrical pressure chamber with a high pressure cylinder, end closures projecting into this cylinder, and means to take up axial forces exerted on the end closures by a pressure 'medium enclosed in the pressure chamber.
  • the furnace chamber and heating means of the furnace are surrounded by an insulating casing in the shape of a sleeve with insulating lid and bottom.
  • Moulding is performed immediately after the sintering and is started at the sintering temperature. During the moulding the temperature must be setat at least such a value that the binder can be deformed enough to allow the sealed spaces to be compressed. Temperature and pressure are dependent upon eachother and on the powder composition.
  • the lid is formed of an outer annular part and an inner part, separate from each other, the outer annular part remaining in position when the inner part is removed.
  • a heat radiation protection ring is provided for insertion into the opening into the annular part when the annular part israised'.
  • a lifting device for the lid is provided inside the housing.
  • the whole invention includes a lid 14 to close the charging open time and by means of said protective collar and radiation protection means the sealing surfaces of the charging opening are effectively protected and, which is extremely important, the degassing time decreases which 7 is of great importance for the length of the process.
  • Previously said furnaces have been used with a central hole for degassing. It is then desirable for this hole to be as large as possible in order to decrease the degassing time, but because of the strength required during the pressure cycle the size of the hole must be limited and there are also considerable problems with insulation.
  • FIG. 1 designates a press stand which is movable between the position shown in the drawing and a position where it surrounds the high pressure chamber 2.
  • the press stand is of the type comprising yokes 3 and 4, spacers 5between the yokes and a strip mantle 6.
  • the stand is carried by wheels 7 running on tracks 8.
  • the high pressure chamber 2 is carried by a pillar 9. This comprises a high pressure cylinder consisting of an inner tube 10 and a surrounding strip mantle 11 with end rings 12 holding the strip mantle together axially and providing attachments for brackets .13 by means of which the high pressure chamber 2 is attached to the pillar 9.
  • the chamber 2 has an upper end closure 14 which projects into the tube 10 of the high pressure cylinder through a pipe flange 15 attached to the tube and provided with sealing surfaces.
  • the pressure chamber 2 has a lower end closure which consists of an annular outer part 19 attached and projecting beneath the tube 10 and a lid 20 projecting into the tube.
  • a ring 21 rests on the part 20 of the end closure. This is fixed to the part 20 in a manner not shown and supports the insulating casing 24 which surrounds the furnace chamber 22 where a billet-23 is being treated, the billet being supported by an insulating bottom joined to the lid 20.
  • electrical heating elements 31 which are passed through conduits 32 connected to lead-ins in the annular part 19 of the end closure.
  • the lid is suitably constructed in sections with decreasing radii, the section having the greatest radius resting on said pipe flange 15 when the lid l4-is placed over the opening.
  • the lowermost section of the lid 14 suitably consists of an'insulating material. Channels 17 for coolant are provided in the lid.
  • the lid 14 is connected by an arm 18 to a lifting device 36 which is arranged to raise and lower said lid to highest and lowest positions, respectively. Channels 37 for coolant run through this arm 18 and the device 36. Both positions of the lid are shown sectioned in FIG. 1. In its lowest position (see the lefthand section) the lid 14 completely closes the charging opening 25. In its uppermost position the lid 14 is not in contact with the pressure chamber, but a gap 25 is formed between the lid 14 and the charging opening.
  • a housing 26 is positioned above the charging opening 25 and the lid 14.
  • the housing 26 is provided with an annular bottom flange 33 which rests against a base flange 34 on the pressure chamber 2.
  • a sealing ring 35 is placed along the entire contact surface between the flanges.
  • a vacuum pump equipment, notshown, is connected by a valved connection 28 to the housing 26, which can be lifted by means of the external lifting members 27. Cooling channels 29 are provided in the walls of the housing 26.
  • the radiation protection means 40 is divided into a lower annular radiation plate section 401 which, through the insulating support 404, rests directly-on the furnace chamber 22 and into an upper circular radia tion plate section 402 which is anchored to the lower section 401 and is held in place at a specific distance from the lower section by spacer elements 405.
  • Lifting yokes 403 may be connected to the spacer elements 405 on the upper side of the upper section 402, which are used when the radiation protection means must be removed while charging the furnace.
  • the radiation plate sections 401 and 402 preferably consist of composite molybdenum plates.
  • FIG. 3 there is also a protective collar 50, shown in FIG. 3, this figure also showing an alternative embodiment of the pipe flange 15.
  • the protective flange 50 is preferably positioned in the charging opening during the vacuum cycle of the furnace when the lid 14 is not closed, to prevent the sealing surfaces of the pipe flange 15 from being subjected to heat radiation and impurities.
  • the protective flange 50 is suitably provided with heat radiation protective material.
  • the collar is projected into the housing 26 to position 502 with the help of a toothed rack 61, after which it is lowered into position 503, for example by means of a trolley running means of a perpendicularly applied toothed rack 71 enclosed in a container 72 fitted to the housing 26.
  • the toothed rack 71 is driven by means of a shaft 73 connected to a driving means 74 fixed by means of a stay 75 to the housing 26.
  • FIG. also'shows an alternative 14 is lowered to its lowermost position and when the embodiment of the housing 26.
  • the process in said furnace takes place in two phases, a vacuum cycle and a pressure cycle.
  • the charge is degassed and the lid 14 is then in its highest position and the housing 26 is positioned over the charging opening and' the lid, as shown in the righthand part of FIG. 1.
  • the radiation protection means 40 is in position according to FIG. 2 immediately after charging has taken place and before the furnace processing starts.
  • cooling channels in the walls of said housing are provided.
  • the protective ring 50 is removed by a member 60 or 70 and the lid charging opening has been closed the housing 26 can be removed by an external lifting device with the help of lifting members 27.
  • the stand 1 is moved in over the furnace chamber 2 and the pressure cycle can start.
  • a furance for vaccum-pressure-sintering having a furnace chamber which is enclosed in and insulated from a surrounding pressure chamber composed of a pressure cylinder, a bottom projecting into said pressure chamber, a lid projecting into the charging opening of said furnace, the improvement comprising means for raising and lowering saidlid between upper and lower positions, and a housing which can-be applied over said charging opening and Eonnected to a vacuum pump during that part of the operating cyclewhenv the pressure in said furnace is below atmospheric pressure, said lid being enclosed by said housing in said furnace and forming a gap between said lid and said charging opening during the vacuum cycle, and said lid closing said charging opening when said housing is removed fromit.
  • said lid 6 In a combination according to claim 1, said lid 6. In a combination according to claim 1, the furnace around the charging opening being provided with a base flange fixed to the furnace said housing having a connecting flange applicable against said base flange.
  • one of said flanges having a seal running along the entire contact surface.
  • said radiation protection means comprising radiation plate sections.
  • the radiation protection means comprising a lower and an upper section of radiation plates, the lower section being annular, support members at the upper part of said furnace chamber, said lower section resting on the support members, the upper section being circular and having a radius greater than the inner radius of said lower section, and a spacer element fixing the upper section at a distance from the lower section.
  • said radiation plate sections comprising molybdenum plates.
  • annular protective collar mounted to be lowered into said charging opening and arranged to protect the area of the opening when in lowered position.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Fluid Mechanics (AREA)
  • Organic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Manufacturing & Machinery (AREA)
  • General Engineering & Computer Science (AREA)
  • Furnace Details (AREA)
  • Powder Metallurgy (AREA)
  • Muffle Furnaces And Rotary Kilns (AREA)
  • Press-Shaping Or Shaping Using Conveyers (AREA)
US00233925A 1971-03-15 1972-03-13 Means in furnaces for vacuum-pressure-sintering Expired - Lifetime US3775043A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
SE03276/71A SE350714B (ru) 1971-03-15 1971-03-15

Publications (1)

Publication Number Publication Date
US3775043A true US3775043A (en) 1973-11-27

Family

ID=20261762

Family Applications (1)

Application Number Title Priority Date Filing Date
US00233925A Expired - Lifetime US3775043A (en) 1971-03-15 1972-03-13 Means in furnaces for vacuum-pressure-sintering

Country Status (6)

Country Link
US (1) US3775043A (ru)
CA (1) CA977548A (ru)
FR (1) FR2129424A5 (ru)
GB (1) GB1382322A (ru)
SE (1) SE350714B (ru)
SU (1) SU420156A3 (ru)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4003697A (en) * 1974-07-30 1977-01-18 Allmanna Svenska Elektriska Aktiebolaget Pressure furnace for treating products at high temperature and high pressure
US4152111A (en) * 1976-12-20 1979-05-01 Asea Aktiebolag Furnace for treatment of material at high temperature and pressure
US4213495A (en) * 1978-08-31 1980-07-22 Ceram-Dent, Inc. Investment casting method
US4325694A (en) * 1979-12-05 1982-04-20 Asea Aktiebolag Cylindrical furnace for treating materials at high temperatures and pressures
US4702696A (en) * 1986-10-28 1987-10-27 Denpac Corp. High temperature vacuum furnace
NL1009267C2 (nl) * 1998-05-27 1999-11-30 Inst Voor Agrotech Onderzoek Hogedrukinrichting.

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3243174A (en) * 1960-03-08 1966-03-29 Chilean Nitrate Sales Corp Dissociation-deposition apparatus for the production of metals
US3342469A (en) * 1965-02-08 1967-09-19 Hayes Inc C I Sealing device for high vacuum furnace
US3427011A (en) * 1967-11-09 1969-02-11 Battelle Development Corp High pressure furnace
US3522357A (en) * 1969-02-03 1970-07-28 Hayes Inc C I Vacuum furnace having a liquid quench and a vertically movable work holder

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3243174A (en) * 1960-03-08 1966-03-29 Chilean Nitrate Sales Corp Dissociation-deposition apparatus for the production of metals
US3342469A (en) * 1965-02-08 1967-09-19 Hayes Inc C I Sealing device for high vacuum furnace
US3427011A (en) * 1967-11-09 1969-02-11 Battelle Development Corp High pressure furnace
US3522357A (en) * 1969-02-03 1970-07-28 Hayes Inc C I Vacuum furnace having a liquid quench and a vertically movable work holder

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4003697A (en) * 1974-07-30 1977-01-18 Allmanna Svenska Elektriska Aktiebolaget Pressure furnace for treating products at high temperature and high pressure
US4152111A (en) * 1976-12-20 1979-05-01 Asea Aktiebolag Furnace for treatment of material at high temperature and pressure
US4213495A (en) * 1978-08-31 1980-07-22 Ceram-Dent, Inc. Investment casting method
US4325694A (en) * 1979-12-05 1982-04-20 Asea Aktiebolag Cylindrical furnace for treating materials at high temperatures and pressures
US4702696A (en) * 1986-10-28 1987-10-27 Denpac Corp. High temperature vacuum furnace
NL1009267C2 (nl) * 1998-05-27 1999-11-30 Inst Voor Agrotech Onderzoek Hogedrukinrichting.
WO1999061146A1 (en) * 1998-05-27 1999-12-02 Ato B.V. High-pressure apparatus
US6491882B1 (en) 1998-05-27 2002-12-10 Ato B.V. High-pressure device

Also Published As

Publication number Publication date
SE350714B (ru) 1972-11-06
DE2211631B2 (de) 1974-07-11
SU420156A3 (ru) 1974-03-15
GB1382322A (en) 1975-01-29
FR2129424A5 (ru) 1972-10-27
DE2211631A1 (de) 1972-09-28
CA977548A (en) 1975-11-11

Similar Documents

Publication Publication Date Title
US3703278A (en) Furnace for sintering powder
US4921666A (en) Process for high efficiency hot isostatic pressing
US3419935A (en) Hot-isostatic-pressing apparatus
US3893852A (en) Method of manufacturing billets from powder
GB1378216A (en) Method of manufacturing a blade having a plurality of internal cooling channels
US3775043A (en) Means in furnaces for vacuum-pressure-sintering
JPS5839708A (ja) 熱間静水圧プレス処理法
US3427011A (en) High pressure furnace
US3940245A (en) Convection shield for isostatic bonding apparatus
US3628779A (en) Furnace for heat-treating objects under high pressure
US4178178A (en) Method of sealing hot isostatic containers
US3695597A (en) Furnace for heat treating objects under pressure
CN206652973U (zh) 一种热等静压用管状包套
US3772009A (en) Method for manufacturing an object from iron-based alloy by isostatic compression
US3598378A (en) Furnace for heat-treating objects under high pressure
US4491302A (en) Hot isostatic pressing apparatus
US3235958A (en) Method of cladding by hydrostatic pressure applied to heated units inside a cold liquid cladding apparatus
US4365409A (en) Method and apparatus for filling sodium into sodium sulphur cells
US3679807A (en) Die-furnace, especially for the fabrication of sintered products
US4283172A (en) Hot isostatic pressure furnace with enhanced insulation properties
US3372212A (en) Process for producing densified and elongate bodies
US3674904A (en) Furnace for making fused quartz hollow slugs
JPS5987032A (ja) 加工品処理装置
US3632954A (en) Diffusion bonding apparatus
US3387079A (en) Process for the fusion of metal oxides