US3442321A - Device for continuous casting of refractory materials - Google Patents

Device for continuous casting of refractory materials Download PDF

Info

Publication number
US3442321A
US3442321A US554530A US55453066A US3442321A US 3442321 A US3442321 A US 3442321A US 554530 A US554530 A US 554530A US 55453066 A US55453066 A US 55453066A US 3442321 A US3442321 A US 3442321A
Authority
US
United States
Prior art keywords
crucible
pulleys
ingot
casting
continuous
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
US554530A
Other languages
English (en)
Inventor
Pierre Blum
Jacques Devillard
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.)
Commissariat a lEnergie Atomique et aux Energies Alternatives CEA
Original Assignee
Commissariat a lEnergie Atomique CEA
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 Commissariat a lEnergie Atomique CEA filed Critical Commissariat a lEnergie Atomique CEA
Application granted granted Critical
Publication of US3442321A publication Critical patent/US3442321A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

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
    • C04B33/00—Clay-wares
    • C04B33/28—Slip casting
    • 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
    • B01J6/00—Heat treatments such as Calcining; Fusing ; Pyrolysis
    • B01J6/005—Fusing
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
    • B22D11/04—Continuous casting of metals, i.e. casting in indefinite lengths into open-ended moulds
    • B22D11/045—Continuous casting of metals, i.e. casting in indefinite lengths into open-ended moulds for horizontal casting
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
    • B22D11/06—Continuous casting of metals, i.e. casting in indefinite lengths into moulds with travelling walls, e.g. with rolls, plates, belts, caterpillars
    • B22D11/0622—Continuous casting of metals, i.e. casting in indefinite lengths into moulds with travelling walls, e.g. with rolls, plates, belts, caterpillars formed by two casting wheels
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D21/00—Casting non-ferrous metals or metallic compounds so far as their metallurgical properties are of importance for the casting procedure; Selection of compositions therefor
    • B22D21/06—Casting non-ferrous metals with a high melting point, e.g. metallic carbides
    • 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
    • C04B33/00—Clay-wares
    • C04B33/30—Drying methods
    • 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
    • C04B35/653—Processes involving a melting step
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
    • C22B9/00—General processes of refining or remelting of metals; Apparatus for electroslag or arc remelting of metals
    • C22B9/16—Remelting metals
    • C22B9/22—Remelting metals with heating by wave energy or particle radiation
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
    • C22B9/00—General processes of refining or remelting of metals; Apparatus for electroslag or arc remelting of metals
    • C22B9/16—Remelting metals
    • C22B9/22—Remelting metals with heating by wave energy or particle radiation
    • C22B9/228—Remelting metals with heating by wave energy or particle radiation by particle radiation, e.g. electron beams

Definitions

  • the aim of this invention is to eliminate this phenomenon by means of a continuous renewal of the wall of said crucible.
  • the invention accordingly has for its object a casting device of the type comprising an electron gun which is disposed axially above a crucible having an axially movable base and a device for the continuous introduction of material to be melted in the eletcron beam, characterized in that the crucible is provided with a side wall which is endowed with uniform motion and is continuously replaced by an identical wall.
  • this device comprises two movable members which are adapted to rotate about axes located at right angles to the ice axis of the crucible said movable members being mounted in adjacent relation and provided with identical grooves forming a circular gap for casting metal at the points of contact of said two movable members.
  • the movable members are grooved pulleys which has axes at right angles to the axis of the crucible and which are in contact along one of their generatrices.
  • the circular gap between the grooves thus forms conjunction with the base a melting pot having a side wall which is renewed progressively as the movement of the pulleys takes place.
  • the crucible wall leaves the melting point before any troublesome deposit has had time to form, and is progressively replaced by a fresh wall. Consequently, the melting process always takes place in a crucible which has a clean wall.
  • FIG. 1 shows partly in side view and partly in axial cross-section a casting device in accordance with the invention
  • FIG. 2 is an overhead plan view of the crucible which is employed in the device of FIG. 1;
  • FIG. 3 is an axial sectional view of an alternative form of construction of the casting device
  • FIG. 4 is an overhead plan view of the crucible of said alternative form of construction.
  • the casting device as a whole is placed within a leaktight chamber which has not been shown in the drawings.
  • a leaktight chamber which has not been shown in the drawings.
  • the axis of said conduit is inclined to the axis of the electron beam 3 which is delivered 'by the gun I in order that the particles of material should be introduced at the center of said beam.
  • a plunger 4 is adapted to move axially between two identical pulleys 6, 8 which are mounted side by side and which are tangent to each other at 10 along one of their generatrices.
  • the grooves 7, 9 of the pulleys 6, 8 form an annular gap 12 having a diameter which corresponds to that of the plunger 4 and consequently of the ingot to be formed.
  • the pulleys 6, 8 are rotatably mounted on shafts 14, 16 which are at right angles to the plunger 4 and carried by end-plates 18 which are rigidly fixed to a base 20.
  • the stem 22 of the plunger 4 is adapted to pass through the center of said base 20 and to slide freely with respect to this latter.
  • said pulleys are driven in rotation in opposite directions as shown by the arrows of FIG. 1 by means of any suitable system such as pulleys, pinions or the like which are fixed on the shafts 14 and 16 and driven by a single motor.
  • each pulley 6, 8 is rigidly fixed to a toothed pinion 17, 19 (FIG. 2) and one of said pinions, namely the pinion 19, is in mesh with a pinion 21 which is driven by a motor 23.
  • the pinion 19 is coupled with the pinion 17 by means of a rack 25 having two parallel sets of teeth; the pinions 17 and 19 and consequently the pulleys 6 and 8 therefore rotate in opposite directions.
  • the rack 25 is secured to the plunger 4 by means of an arm 27, with the result that the movement of rotation of the 3 pulleys causes the said plunger 4 to slide with respect to the base 20.
  • the crucible 12 is thus constituted on the one hand by the wall of the grooves 7 and 9 at the tangential point 10 or point of contact of the pulleys, said wall being continuously withdrawn and replaced while remaining identical with itself and, on the other hand, by the plunger 4 which forms a movable base and accordingly recedes from said wall progressively as the ingot is formed, said pulley grooves and said plunger being displaced at the same time in a synchronized movement.
  • the molten material is cast in said crucible 12 which is cooled by circulation of fluid within the conduits 24.
  • said material forms a cylindrical ingot 28 as shaped by the grooves 7 and 9 and the casting skin in particular becomes sufiiciently strong to dispense with any further need of lateral support.
  • the plunger therefore extracts the ingot 28 from the gap 12 in a progressive manner while the pulleys 6 and 8 rotate, thereby progressively moving said ingot away from the walls of the grooves 7 and 9 which have just been in contact with the molten material and bringing into contact a clean portion of the same grooves which progressively re-forms the crucible 12.
  • the speed of rotation of the pulleys is preferably very low, for example 10 to millimeters per minute in tangential velocity, so as to enable the ingot to form normally but remains sufficiently high to prevent any possibility of evaporation to an extent which might result in the formation of a troublesome layer on the walls of the grooves.
  • the movement of the plunger and consequently the rate of extraction of the ingot is dependent on said tangential velocity, which is dependent in turn on the nature of the material and on the diameter of the ingot to be obtained.
  • the assembly consisting of base 20 and pulleys 6, 8 which is rigidly coupled for rotation with the stem 22 of the plunger 4 by means of the rack 25 or, in other words, the assembly consisting of all the components of the crucible 12, is driven in rotation about the axis of said plunger, for example by means of a set of teeth 31 (FIG. 1) which is carried by the base 20 and engaged with a pinion 29 which is driven in rotation by a motor 30.
  • the grooved pulleys 32, 34 which constitute the side wall of the crucible are provided with one or a number of teeth 36 (three in the case of the example shown in the figure) which partially close the groove 33, 35 and form a throttled section of the crucible.
  • the ingot 38 is consequently provided at uniform intervals with necked portions which make it possible to break off the ingot in sections without difficulty.
  • the casting operation is preferably carried out as a continuous process. This can readily be ensured since the bottom of the crucible is constituted by the metal which has just set. Each ingot section which is formed can thus be detached as it is delivered from the crucible and no longer needs to be supported.
  • a plunger or like member is employed only at the beginning of the casting operation so as to provide the crucible with an initial base or end-wall and is then dispensed with, the ingot being first driven down by the teeth 36 and then displaced as a result of the motion of the pulleys themselves.
  • the pinions 37 and 39 which are rigidly fixed to the pulleys 32 and 34 are then directly engaged with each other (FIG. 4) whilst one of said pulleys, namely the pulley 39, is engaged with a pinion 41 which is driven by a motor 43.
  • the base 20 which supports the pulleys is driven in rotation in the same manner as in the previous example and the wall of the crucible rotates about the axis of this latter.
  • the base 20 is pierced by a central bore 44 through which the ingot 38 can slide freely until it reaches a point located opposite to a breaking-off device of any known type (tongs or the like).
  • each of the pulleys 6 and 8 or 32 and 34 for example at a point which is diametrically opposite to the tangential point 10, for a system such as a brush, scraper or like system, not shown, for the purpose of cleaning the bottom of the grooves 7, 9 or 33, 35.
  • the diameter of the pulleys can also be fairly substantial in order that the draw-taper which is provided by the radius of curvature is not excessive and that the height or length over which the ingot solidifies is substantially rectilinear.
  • the movable members could be endowed with any shape which is designed to permit of uniform displacement of the grooves above the plunger.
  • a device for continuously casting granular refractory materials into an ingot comprising:
  • a crucible in which the granular refractory materials to be cast are melted and subsequently cast into a continuous ingot, said crucible having an axially movable base;
  • an electron gun disposed above said crucible for continuously melting granular refractory material in the crucible;
  • a continuous-casting device in accordance with claim 1 characterized in that the crucible side wall comprises two movable members which are adapted to rotate about axes located at right angles to the axis of the crucible, said movable members being mounted in adjacent touching relation and provided with identical grooves forming a circular gap defining the crucible side wall for castng metal at the points of contact of said two movable members 3.
  • a continuous-casting device in accordance with claim 2 characterized in that the movable members are grooved pulleys which have axes at right angles to the axis of the crucible and which are in contact along one of their generatrices.
  • a continuous-casting device in accordance with .Iclaim 3 characterized in that the movable members are carried by a base which is rotatable about the axis of the crucible.
  • each pulley comprises at least one tooth for partially closing the crucible.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Ceramic Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Organic Chemistry (AREA)
  • Materials Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Physics & Mathematics (AREA)
  • Structural Engineering (AREA)
  • Plasma & Fusion (AREA)
  • Metallurgy (AREA)
  • Dispersion Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Thermal Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Toxicology (AREA)
  • Inorganic Chemistry (AREA)
  • Continuous Casting (AREA)
  • Manufacture And Refinement Of Metals (AREA)
  • Furnace Housings, Linings, Walls, And Ceilings (AREA)
US554530A 1965-06-03 1966-06-01 Device for continuous casting of refractory materials Expired - Lifetime US3442321A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR19352A FR1445684A (fr) 1965-06-03 1965-06-03 Dispositif de coulée continue de matériaux réfractaires

Publications (1)

Publication Number Publication Date
US3442321A true US3442321A (en) 1969-05-06

Family

ID=8580704

Family Applications (1)

Application Number Title Priority Date Filing Date
US554530A Expired - Lifetime US3442321A (en) 1965-06-03 1966-06-01 Device for continuous casting of refractory materials

Country Status (11)

Country Link
US (1) US3442321A (de)
BE (1) BE681646A (de)
CH (1) CH469517A (de)
DE (2) DE1508800C2 (de)
ES (1) ES327546A1 (de)
FR (1) FR1445684A (de)
GB (1) GB1108930A (de)
IL (1) IL25865A (de)
LU (1) LU51223A1 (de)
NL (1) NL6607559A (de)
SE (1) SE327055B (de)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4759887A (en) * 1985-05-24 1988-07-26 Heliotronic Forschungs- und Entwicklungs-gesellschaft fur Solarzellen-Grundstoffe mbH Apparatus and process for the manufacture of shaped bodies from silicon granulates
WO2004029332A2 (en) * 2002-09-25 2004-04-08 Qinetiq Limited Purification of electrochemically deoxidised refractory metal particles by heat processing

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA1112430A (en) * 1977-12-19 1981-11-17 Norton Company Abrasive casting apparatus and process
DE19956479C2 (de) * 1999-11-24 2001-11-22 Hengst Walter Gmbh & Co Kg Verfahren und Vorrichtung zur Herstellung von Leichtmetall-Pellets
CN100471618C (zh) 2001-12-21 2009-03-25 威兰德-沃克公开股份有限公司 塑性材料加工制造的有规定断离位置的半成品及其用途
DE10163038B4 (de) * 2001-12-21 2004-07-15 Wieland-Werke Ag Halbzeug aus duktilem Material mit Sollbruchstellen und dessen Verwendung

Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US441375A (en) * 1890-11-25 Art of making metal tubing
DE823778C (de) * 1948-11-05 1951-12-06 Stolberger Zink Ag Verfahren und Vorrichtung zum ununterbrochenen Giessen von Leicht- und Schwermetallen, insbesondere von Zink
DE898135C (de) * 1948-12-19 1953-11-26 Adolf Reimitz Verfahren zum Herstellen von Blechen, Baendern, Profilen und Rohren aus Metallen durch Giessen duenner Vorprodukte im Walzenspalt
FR1049394A (fr) * 1951-06-28 1953-12-29 Ile D Etudes De Centrifugation Perfectionnements à la coulée continue des métaux
GB734347A (en) * 1951-07-14 1955-07-27 Joseph Barry Brennan Improvements in or relating to the casting method and apparatus
US2942098A (en) * 1958-08-04 1960-06-21 Stauffer Chemical Co Method for heating materials by electron bombardment in a vacuum
FR1369428A (fr) * 1963-06-21 1964-08-14 Commissariat Energie Atomique Perfectionnements apportés aux procédés pour la fabrication de granulés de carbures métalliques, notamment de carbures d'uranium
US3183563A (en) * 1962-06-05 1965-05-18 Temescal Metallurgical Corp Apparatus for continuous foil production by vapor deposition
US3237254A (en) * 1962-06-26 1966-03-01 Stauffer Chemical Co Vacuum casting
US3265801A (en) * 1960-08-22 1966-08-09 Ass Elect Ind Electron beam furnaces
US3351126A (en) * 1964-09-25 1967-11-07 Western Electric Co Casting wheel apparatus
US3388736A (en) * 1963-04-04 1968-06-18 Commissariat Energie Atomique Furnace for manufacturing ingots or bars of metal or alloys, particularly bars of uranium carbide

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE59694C (de) * E. NORTON in Maywood, Staat Illinois, und E. ADCOCK, Rechtsanwalt, in Chicago, Staat Illinois, V. St. A Verfahren und Vorrichtung zur Herstellung von Metallröhren in der durch das Patent Nr. 53731 bekannt gewordenen Art und Weise
FR1043564A (fr) * 1951-04-05 1953-11-10 Ile D Etudes De Centrifugation Procédé et dispositifs pour la fabrication de corps creux métalliques
DE1023197B (de) * 1955-03-12 1958-01-23 Degussa Vorrichtung zum Abziehen von Gussstraengen im Stranggiessverfahren

Patent Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US441375A (en) * 1890-11-25 Art of making metal tubing
DE823778C (de) * 1948-11-05 1951-12-06 Stolberger Zink Ag Verfahren und Vorrichtung zum ununterbrochenen Giessen von Leicht- und Schwermetallen, insbesondere von Zink
DE898135C (de) * 1948-12-19 1953-11-26 Adolf Reimitz Verfahren zum Herstellen von Blechen, Baendern, Profilen und Rohren aus Metallen durch Giessen duenner Vorprodukte im Walzenspalt
FR1049394A (fr) * 1951-06-28 1953-12-29 Ile D Etudes De Centrifugation Perfectionnements à la coulée continue des métaux
GB734347A (en) * 1951-07-14 1955-07-27 Joseph Barry Brennan Improvements in or relating to the casting method and apparatus
US2942098A (en) * 1958-08-04 1960-06-21 Stauffer Chemical Co Method for heating materials by electron bombardment in a vacuum
US3265801A (en) * 1960-08-22 1966-08-09 Ass Elect Ind Electron beam furnaces
US3183563A (en) * 1962-06-05 1965-05-18 Temescal Metallurgical Corp Apparatus for continuous foil production by vapor deposition
US3237254A (en) * 1962-06-26 1966-03-01 Stauffer Chemical Co Vacuum casting
US3388736A (en) * 1963-04-04 1968-06-18 Commissariat Energie Atomique Furnace for manufacturing ingots or bars of metal or alloys, particularly bars of uranium carbide
FR1369428A (fr) * 1963-06-21 1964-08-14 Commissariat Energie Atomique Perfectionnements apportés aux procédés pour la fabrication de granulés de carbures métalliques, notamment de carbures d'uranium
US3351126A (en) * 1964-09-25 1967-11-07 Western Electric Co Casting wheel apparatus

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4759887A (en) * 1985-05-24 1988-07-26 Heliotronic Forschungs- und Entwicklungs-gesellschaft fur Solarzellen-Grundstoffe mbH Apparatus and process for the manufacture of shaped bodies from silicon granulates
WO2004029332A2 (en) * 2002-09-25 2004-04-08 Qinetiq Limited Purification of electrochemically deoxidised refractory metal particles by heat processing
WO2004029332A3 (en) * 2002-09-25 2004-10-21 Qinetiq Ltd Purification of electrochemically deoxidised refractory metal particles by heat processing
US20060130610A1 (en) * 2002-09-25 2006-06-22 Ward-Close Charles M Purification process

Also Published As

Publication number Publication date
GB1108930A (en) 1968-04-10
SE327055B (de) 1970-08-10
LU51223A1 (de) 1966-08-01
NL6607559A (de) 1966-12-05
DE1408800B2 (de) 1970-05-14
IL25865A (en) 1970-03-22
DE1508800B1 (de) 1970-05-14
FR1445684A (fr) 1966-07-15
DE1408800A1 (de) 1970-05-14
ES327546A1 (es) 1967-07-16
CH469517A (fr) 1969-03-15
DE1508800C2 (de) 1970-12-17
BE681646A (de) 1966-10-31

Similar Documents

Publication Publication Date Title
US3693697A (en) Controlled solidification of case structures by controlled circulating flow of molten metal in the solidifying ingot
US2445670A (en) Apparatus for producing cast metal bodies
US2290083A (en) Continuous molding machine
US2130202A (en) Continuously casting pipe
US3746077A (en) Apparatus for upward casting
US2385206A (en) Method and apparatus for producing metal bodies
US3442321A (en) Device for continuous casting of refractory materials
US2770022A (en) Method of continuously casting molten metal
US2931082A (en) Casting method and apparatus
US2380238A (en) Method and apparatus for producing cast metal bodies
US3210812A (en) Continuous casting mold
US3410333A (en) Method of continuous casting
US2496235A (en) Method for the continuous casting of metal slabs
US3340924A (en) Apparatus for continuous casting of hollow billets
US3450188A (en) Continuous casting method and arrangement
US3261059A (en) Device for cooling the rod being formed in a machine for the continuous casting of metal rods of indefinite length
US3354936A (en) Continuous casting process
US3730254A (en) Roller pair type continuous casting apparatus
US3414043A (en) Method for the continuous transferring of liquid metals or alloys into solid state with desired cross section without using a mould
US2944310A (en) Method of continuous casting
US3848657A (en) Apparatus for electroslag melting of hollow ingots
US3287769A (en) Vacuum melting and casting apparatus
CN100551583C (zh) 容积补偿法连续铸造无液芯偏心灰铸铁型材的设备
US4813472A (en) Melt overflow system for producing filamentary and film products directly from molten materials
US2073200A (en) Centrifugal casting