EP0529194B1 - Verfahren zur Herstellung eines Körpers aus einem warmrissempfindlichen Werkstoff und Giessform - Google Patents

Verfahren zur Herstellung eines Körpers aus einem warmrissempfindlichen Werkstoff und Giessform Download PDF

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Publication number
EP0529194B1
EP0529194B1 EP92105423A EP92105423A EP0529194B1 EP 0529194 B1 EP0529194 B1 EP 0529194B1 EP 92105423 A EP92105423 A EP 92105423A EP 92105423 A EP92105423 A EP 92105423A EP 0529194 B1 EP0529194 B1 EP 0529194B1
Authority
EP
European Patent Office
Prior art keywords
melt
mould
side walls
base
cast
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
EP92105423A
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German (de)
English (en)
French (fr)
Other versions
EP0529194A1 (de
Inventor
Karl-Heinz Goy
David Francis Dr. Lupton
Michael Dr. Hörmann
Willibald Kowarschik
Klaus Rzesnitzek
Berthold Zurowski
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.)
WC Heraus GmbH and Co KG
Original Assignee
WC Heraus GmbH and Co KG
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Filing date
Publication date
Application filed by WC Heraus GmbH and Co KG filed Critical WC Heraus GmbH and Co KG
Publication of EP0529194A1 publication Critical patent/EP0529194A1/de
Application granted granted Critical
Publication of EP0529194B1 publication Critical patent/EP0529194B1/de
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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D25/00—Special casting characterised by the nature of the product
    • B22D25/06—Special casting characterised by the nature of the product by its physical properties
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C9/00—Moulds or cores; Moulding processes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C3/00—Selection of compositions for coating the surfaces of moulds, cores, or patterns
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D27/00—Treating the metal in the mould while it is molten or ductile ; Pressure or vacuum casting
    • B22D27/04—Influencing the temperature of the metal, e.g. by heating or cooling the mould

Definitions

  • the invention relates to a method for producing a body from a heat-crack-sensitive material, in particular from an alloy, by pouring a melt of the material into a casting mold with thermally insulated side walls and with a bottom made of good heat-conducting material and cooling the melt in the casting mold, the as the interface between the melt and the already solidified material, the solidification front that forms essentially runs parallel to the bottom and moves from the bottom towards the free melt surface during the solidification of the melt. Furthermore, the invention relates to a casting mold for carrying out the method with four thermally insulated, smooth side walls opposing each other in pairs and with a well heat-conducting base made of metal.
  • DD-PS 207 076 describes a process for the production of round disks made of metal silicides with a diameter of 156 mm and a disk thickness of 8 mm.
  • a melt of a Cr-Si-W alloy is poured into a graphite mold preheated to ⁇ 700 ° Celsius and thermally insulated on the outside and evenly under vacuum at a cooling rate of less than 20 ° C / min. cooled to room temperature.
  • This process is well suited for the production of thin panes, however, in the case of castings with larger wall thicknesses, cracks and cavities occur despite preheating the mold and slow cooling, which are caused, for example, by an unfavorable cast texture of the cast body, from an accumulation of harmful excretions, segregations or pores in the Center of the casting or may be caused by a hindrance to the shrinkage of the casting during cooling due to inhomogeneities on the inner walls of the mold.
  • a cylindrical casting mold is proposed in DD-PS 257 350, on the inside of which a soft insulating layer is glued, which does not offer greater resistance to the shrinkage of the cast body, and into which a good heat-conducting, metallic base plate of the same chemical composition as that of the material to be cast is used.
  • the targeted heat dissipation from the melt via the base plate achieves directional solidification of the melt in such a way that only a single solidification front is formed between the already solidified material and the melt of the material, which essentially starts from the bottom of the casting mold with progressive solidification of the melt moved parallel to the floor in the direction of the free enamel surface.
  • the solidification of the material melts takes place very slowly in the known methods for directional solidification. This is achieved, for example, in that the casting mold is preheated before the melt is poured off and then cooled evenly and slowly.
  • DD-PS 207 076 mentions a cooling rate of less than 20 ° C./min to room temperature.
  • DE-OS 35 32 131 From DE-OS 35 32 131 it is known to maintain a temperature gradient over the height of the side walls of the casting mold, the temperature at the upper edge of the casting mold being in the range of the melting temperature of the material to be cast. This ensures exact control of the directional solidification of the melt, starting from the heat-dissipating floor up to the upper edge of the casting mold. The melt solidifies extremely slowly. The speed at which the solidification front progresses is mentioned in DE-OS 35 32 131 4 cm / h.
  • Slow cooling can also promote the formation or growth of undesirable inhomogeneities, such as precipitates or segregations, in many of the materials susceptible to this, which, when the material is used, for example as a target for coating purposes, can cause fluctuations in the coating result to lead.
  • undesirable inhomogeneities in the material structure can also promote cracks.
  • gaseous impurities such as water or oxygen
  • DD-PS 257 350 proposes the use of a base plate which has the same chemical composition as that of the metallic material to be cast.
  • a similar solution proposal is also based on the method according to EP-B1 237 325, in which a base plate made of a material is used which combines with the material to be cast to form a uniform structure and which has a lower expansion coefficient than that of the material to be cast having.
  • a cylindrical casting as is produced by means of the casting mold according to DD-PS 257 350, has to be sawn into appropriate disks or broken up in some other way.
  • the resulting material removal and the additional waste caused by the stress on the cast body during processing inevitably lead to material losses.
  • Another method and a casting mold according to the type specified are known from Japanese patent application JP-A 10 11 060.
  • the casting mold described therein enables a directional solidification of the melt cast in from the bottom of the casting mold.
  • the casting mold is provided with four smooth, thermally insulating side walls made of aluminum oxide, which face each other in pairs, and a base made of cast iron with good thermal conductivity. Due to the directional solidification, the formation of a casting judge when the melt solidifies is avoided.
  • a target made from the solidified casting block is crack-free and ensures atomization under stable discharge conditions.
  • the present invention is based on the object of specifying a simple and cost-effective method for producing plate-shaped bodies from materials which are sensitive to hot cracks, which enables casting of crack-free and homogeneous bodies, and to provide a simple, low-wear casting mold for carrying out the method from which the casting body is made is easy to remove and which allows the melt to cool down quickly while at the same time being directed to solidification.
  • the melt is poured into a casting mold, the temperature in degrees Celsius of which corresponds to a maximum of one third of the liquidus temperature of the material, and in the form of a rectangular plate with a plate thickness in the range between 5 mm and 20 mm is poured, the solidification front moving substantially towards one of the long sides of the plate when the melt solidifies.
  • Both the side walls of the mold and the bottom can be at a uniform temperature. It is also possible to cool the floor than that To hold side walls or to cool it additionally while the melt is cooling.
  • the amount of heat to be dissipated via the floor is kept as low as possible and rapid solidification of the melt is supported.
  • the heat is dissipated preferably in the direction of the bottom of the casting mold, so that a solidification front forms as the interface between the melt and already solidified material, which runs essentially parallel to the bottom and which moves towards the free melt surface.
  • a rapid cooling of the melt also prevents the possible formation of inhomogeneities, such as excretions or segregations, or at least reduces their growth rate.
  • inhomogeneities such as excretions or segregations
  • one rapid cooling reduces the uptake of impurities in the melt via the gas phase, over the side walls or over the bottom of the casting mold.
  • impurities such as water or oxygen, can change the homogeneous lattice structure of the material and thus have a detrimental effect both on the strength behavior of the cast body and on its purity.
  • the width of the plate corresponds to at least five times the plate thickness
  • the width of the plate being understood to mean the lateral dimension that spans the plane with the plate thickness runs parallel to the ground.
  • the mirror-symmetrical stress profile that forms in the solidifying cast body is not disturbed thereby.
  • the length of the plate-shaped cast body by which is meant the lateral dimension of the cast body extending perpendicularly or almost perpendicular to the floor, should advantageously correspond to at least five times the plate thickness.
  • this length cannot easily be maintained for every material, since the length within which a directional solidification of the cast body takes place depends, among other things, on the thermal conductivity of the material.
  • a method in which a composition of at least one transition metal and at least one rare earth metal and in particular a material with a composition in which between 25% by weight and 65% by weight iron, between, is selected as the material to be cast has proven particularly useful 35% by weight and 60% by weight of terbium and at most 15% by weight of cobalt are contained.
  • very homogeneous cast bodies with an unusually good homogeneity and deviations in the composition within the cast body of less than half a percent of the target contents of the respective metals could be achieved.
  • the above object is achieved according to the invention starting from the casting mold mentioned at the outset in that the base consists of a metal which does not form a mechanical connection with the melt of the material, and that the inner walls of the side walls have an average roughness depth of at most Have 100 microns and that they include a room with a rectangular base, the short leg between 5 mm and 20 mm long, the length of the long leg and the height of the space encompassed by the side walls are at least five times the length of the short leg.
  • the formation of the casting mold with side walls, the inner walls of which have an average surface roughness of at most 100 ⁇ m, allows the material melt or the solidified casting body to cool down more quickly, since the risk of crack initiation from its surface is reduced on smooth surfaces of the casting body. In addition, undercuts and serrations and thus a hindrance to the shrinkage of the cast body during cooling are avoided.
  • the fact that the bottom consists of a metal that does not form a mechanical connection with the melt of the material ensures that the casting body can be easily removed from the casting mold.
  • the base plate can be optimized in terms of its thermal conductivity and its temperature shock resistance when pouring hot melt over it and can be used several times.
  • the side walls face each other in pairs and comprise a room with a rectangular base, the short one Leg is between 5 mm and 20 mm long, the length of the long leg and the height of the space encompassed by the side walls being at least five times the length of the short leg, an easy pouring of the melt of the material and a uniform filling of the mold from Allows floor.
  • Particularly smooth inner walls have casting molds whose side walls consist of glass, in particular quartz glass or of finely polished graphite or boron nitride. Casting molds with such side walls are dimensionally stable even at high temperatures, in particular also in the case of castings with long lateral dimensions. Undercuts or serrations are almost impossible with such molds, the castings are particularly easy to remove and they have a very smooth surface. As a result, the formation of cracks in the cast body starting from the surface is reduced and the cast bodies can cool down more quickly.
  • Graphite and boron nitride are also particularly soft materials that offer little resistance to the shrinkage of the cast body when it cools down.
  • the side walls have a thickness in the range between 2 mm and 6 mm. It is thereby achieved that the side walls warm up very quickly when the melt is poured in and further dissipation of heat via the side walls is reduced.
  • the base and the side walls have proven useful to design the base and the side walls to be detachable from one another. Furthermore, an embodiment has proven to be cheap proven, in which the bottom with at least two opposing side walls each includes an angle of less than 90 °, so that the solidified casting between the side walls is seen in the direction of the bottom, is slightly flared and thereby the side walls are lifted slightly upwards from it can be.
  • a section through a casting mold 1 is shown schematically, in which on a base 2 made of copper, which has a total mass of approx. 4000 g and which serves as a heat sink, four side walls 4, 5, 6 face each other in pairs ( a side wall is not shown due to the representation as a section).
  • the side walls 4, 5, 6, which consist of 4 mm thick quartz glass panes with an average surface roughness of 10 ⁇ m, are surrounded by an insulating layer 7.
  • the side walls 4, 5, 6 comprise a space 8 with a rectangular base, the short leg of which is 9 mm and the long leg of which is 90 mm long.
  • the inner walls of the side walls 4, 5, 6 are covered with a thin layer 9 of boron nitride powder.
  • the inner walls of the opposing, wider side walls 5, 6 do not run parallel to each other, but they make an angle of 89 ° with the bottom 2, so that the space 8 enclosed by the side walls 4, 5, 6 is slightly downward widened conically.
  • the solidification front moves from the bottom 2 in the direction of the free melt surface. With increasing thickness of the already solidified layer, however, the heat dissipation via the bottom takes place more slowly, so that the rate of solidification decreases in the direction perpendicular to the bottom 2.
  • the solidification of the melt and the cooling of the cast body take place without any additional heat from the outside. Due to the small wall thickness of the side walls 4, 5, 6, they heat up to such an extent due to the heat introduced with the melt that there is hardly any solidification from the side walls.
  • the melt therefore solidifies at the greatest possible speed over its entire height in an almost directed manner. Due to the rapid solidification of the melt, a mirror-symmetrical stress profile forms in the cast body during cooling. The mirror plane runs parallel and in the center of the wide side walls 5, 6.
  • the thickness of the plate thus produced is approximately 8.5 mm; their width is approximately 88 mm and the height within which the melt solidifies in a directional manner is approximately 180 mm. It can be used directly as a target for coating purposes after minor post-processing.
  • Castings made from this alloy using the method according to the invention showed hardly measurable differences in the chemical composition in the area of the solidified bottom and in the area of the last solidified free melt surface. For example, differences in the terbium concentration of less than 0.3% of the weighed amount were measured between these two areas. Such good homogeneity can only be achieved through rapid solidification.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Mold Materials And Core Materials (AREA)
  • Molds, Cores, And Manufacturing Methods Thereof (AREA)
  • Crystals, And After-Treatments Of Crystals (AREA)
EP92105423A 1991-08-22 1992-03-30 Verfahren zur Herstellung eines Körpers aus einem warmrissempfindlichen Werkstoff und Giessform Expired - Lifetime EP0529194B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE4127792 1991-08-22
DE4127792A DE4127792C1 (enrdf_load_stackoverflow) 1991-08-22 1991-08-22

Publications (2)

Publication Number Publication Date
EP0529194A1 EP0529194A1 (de) 1993-03-03
EP0529194B1 true EP0529194B1 (de) 1996-11-06

Family

ID=6438843

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EP92105423A Expired - Lifetime EP0529194B1 (de) 1991-08-22 1992-03-30 Verfahren zur Herstellung eines Körpers aus einem warmrissempfindlichen Werkstoff und Giessform

Country Status (5)

Country Link
US (1) US5236033A (enrdf_load_stackoverflow)
EP (1) EP0529194B1 (enrdf_load_stackoverflow)
JP (1) JP2925846B2 (enrdf_load_stackoverflow)
KR (1) KR960012864B1 (enrdf_load_stackoverflow)
DE (2) DE4127792C1 (enrdf_load_stackoverflow)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2772765B2 (ja) * 1994-10-14 1998-07-09 本田技研工業株式会社 チクソキャスティング用鋳造材料の加熱方法
US7023935B2 (en) * 2001-11-27 2006-04-04 Mitsubishi Electric Research Laboratories, Inc. Trellis based maximum likelihood signal estimation method and apparatus for blind joint channel estimation and signal detection
DE10352183A1 (de) * 2003-11-05 2005-06-23 Dihag Deutsche Giesserei- Und Industrie-Holding Ag Gießverfahren zur Herstellung eines Gußteils
KR101228438B1 (ko) * 2010-12-08 2013-02-01 주식회사 포스코 크기 가변식 주조 형틀
CN109540642B (zh) * 2019-01-09 2023-09-08 四川大学 一种批量制作不同倾角类岩体裂隙试样的模具
US11697152B2 (en) * 2020-02-14 2023-07-11 Bryan Kekst Brown Vitriforming—a method for forming material at liquid temperature within a vitreous forming medium

Family Cites Families (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2951272A (en) * 1958-09-22 1960-09-06 Gen Electric Method and apparatus for producing grain-oriented ingots
US3204301A (en) * 1960-10-24 1965-09-07 M C Flemings Jr Casting process and apparatus for obtaining unidirectional solidification
FR2201937B1 (enrdf_load_stackoverflow) * 1972-10-06 1975-01-03 Onera (Off Nat Aerospatiale)
JPS5139602A (en) * 1974-10-02 1976-04-02 Ajinomoto Kk Horumiruki no datsuriho
US4243471A (en) * 1978-05-02 1981-01-06 International Business Machines Corporation Method for directional solidification of silicon
JPS5573441A (en) * 1978-11-27 1980-06-03 Hitachi Ltd Control method of solidification structure of metal
JPS57106447A (en) * 1980-12-25 1982-07-02 Seiko Epson Corp Mold for rare earth magnet
FR2500768A1 (fr) * 1981-02-27 1982-09-03 Labo Electronique Physique Creuset demontable, procede de fabrication, et cellules solaires au silicium ainsi obtenues
JPS5829546A (ja) * 1981-08-17 1983-02-21 Kawasaki Steel Corp 偏析のない大型鋼塊の製造方法
DD207076A3 (de) * 1981-12-23 1984-02-15 Adw Ddr Verfahren zur herstellung von formkoerpern aus metallsiliziden
JPS5916652A (ja) * 1982-07-19 1984-01-27 Honda Motor Co Ltd 軽合金鋳造用チラ−
DE3532131A1 (de) * 1985-09-10 1987-03-12 Bayer Ag Verfahren zur gerichteten erstarrung von metallschmelzen
DD257350A3 (de) * 1985-11-07 1988-06-15 Mansfeld Kombinat W Pieck Veb Giessform fuer das giessen von warmrissempfindlichen metallischen werkstoffen
GB8605878D0 (en) * 1986-03-10 1986-04-16 Johnson Matthey Plc Casting transition metal alloy
DE3627764A1 (de) * 1986-08-16 1988-02-18 Linn Elektronik Gmbh Verfahren zur herstellung von erstarrten legierungskoerpern
JPS63130769A (ja) * 1986-11-20 1988-06-02 Mitsui Eng & Shipbuild Co Ltd ターゲット材
US4840699A (en) * 1987-06-12 1989-06-20 Ghemini Technologies Gallium arsenide crystal growth
JPS6411060A (en) * 1987-07-06 1989-01-13 Seiko Epson Corp Mold for casting
JPS6418561A (en) * 1987-07-14 1989-01-23 Mitsubishi Metal Corp Production of active metal having unidirectional solidified structure and its alloy casting
US5111871B1 (en) * 1989-03-17 1993-12-28 J. Cook Arnold Method of vacuum casting
DE69014049T2 (de) * 1989-09-08 1995-03-23 Toshiba Kawasaki Kk Magnetostriktive Kobalt-Eisenlegierungen und ihre Produktanwendungen.

Also Published As

Publication number Publication date
DE59207477D1 (de) 1996-12-12
JPH07171660A (ja) 1995-07-11
DE4127792C1 (enrdf_load_stackoverflow) 1992-08-06
KR930003997A (ko) 1993-03-22
US5236033A (en) 1993-08-17
EP0529194A1 (de) 1993-03-03
KR960012864B1 (ko) 1996-09-25
JP2925846B2 (ja) 1999-07-28

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