EP3852951A1 - Noyau de coulée pour moules de fonderie et procédé de fabrication - Google Patents

Noyau de coulée pour moules de fonderie et procédé de fabrication

Info

Publication number
EP3852951A1
EP3852951A1 EP19773055.9A EP19773055A EP3852951A1 EP 3852951 A1 EP3852951 A1 EP 3852951A1 EP 19773055 A EP19773055 A EP 19773055A EP 3852951 A1 EP3852951 A1 EP 3852951A1
Authority
EP
European Patent Office
Prior art keywords
core
casting
binder
mold
ceramic particles
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.)
Pending
Application number
EP19773055.9A
Other languages
German (de)
English (en)
Inventor
Franz-Josef Wöstmann
Lukas Stumm
Christian Soltmann
Matthias Busse
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.)
Fraunhofer Gesellschaft zur Forderung der Angewandten Forschung eV
Original Assignee
Fraunhofer Gesellschaft zur Forderung der Angewandten Forschung eV
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 Fraunhofer Gesellschaft zur Forderung der Angewandten Forschung eV filed Critical Fraunhofer Gesellschaft zur Forderung der Angewandten Forschung eV
Publication of EP3852951A1 publication Critical patent/EP3852951A1/fr
Pending legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C9/00—Moulds or cores; Moulding processes
    • B22C9/10—Cores; Manufacture or installation of cores
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C1/00—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds
    • B22C1/16—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents
    • B22C1/18—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents of inorganic agents
    • B22C1/181—Cements, oxides or clays
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C1/00—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds
    • B22C1/16—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents
    • B22C1/18—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents of inorganic agents
    • B22C1/185—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents of inorganic agents containing phosphates, phosphoric acids or its derivatives
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C1/00—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds
    • B22C1/16—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents
    • B22C1/18—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents of inorganic agents
    • B22C1/186—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents of inorganic agents contaming ammonium or metal silicates, silica sols
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C1/00—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds
    • B22C1/16—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents
    • B22C1/20—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents of organic agents

Definitions

  • Casting core for casting molds and process for its production
  • the present invention relates to a casting core for casting molds, the casting core comprising a core core and a core jacket arranged around the core core.
  • the core jacket contains or consists of ceramic particles bound with a binder.
  • the core core contains ceramic particles bound with a binder as well as one or more placeholder elements.
  • the / the placeholder element (s) is / are at least partially thermally decomposable.
  • the present invention also relates to a method for producing the casting core according to the invention and the use of the casting core according to the invention.
  • Casting cores or cores are used when casting components in molds in order to keep the cavities provided in the later component clear when filling the mold.
  • the casting cores must have the necessary strength and remain dimensionally stable during the casting process. Soaking the casting cores with melt when casting with increased pressure must be closed. In order to obtain a good casting surface, additional requirements are placed on the core material. Here, as little as possible wetting between the melt and the casting core and a smooth, chemically suitable surface is advantageous. Particularly with casting cores for the production of a complex inner shape, good disintegration is required in order to ensure the removal of the core material from the component after casting.
  • refractory fillers e.g. quartz sand, zircon sand, aluminosilicates, but also inorganic hollow spheres
  • an organic e.g. synthetic resin, protein binder
  • inorganic binder silicate binder, phosphate binder
  • the shaping can be done by pressing, core shooting or casting.
  • the surface of the cores can be improved by applying coatings.
  • the thermal decomposition of the organic binder during the casting process weakens the core structure and enables the core material to be removed from the casting, but is also associated with the emission of environmentally harmful gases.
  • a casting core for casting molds which comprises a core core and a core shell arranged around the core core.
  • the core jacket contains or consists of ceramic particles bound with a binder.
  • the core core contains ceramic particles bound with a binder as well as one or more placeholder elements.
  • the placeholder element is or the placeholder elements are at least partially thermally decomposable.
  • the casting core according to the invention advantageously comprises several parts, namely an inner part, the core core, and an outer part, the core jacket. Due to this core structure with a core jacket which is in contact with the melt and a core core, the casting core according to the invention is optimally adapted to the different requirements during and after a casting process. Due to the presence of the thermally decomposable placeholder elements in the core core, the core core can be destabilized by thermal stress, which simplifies the removal of the casting core from the casting. Due to the heat input during the casting process, which is, for example, at a temperature in the range from 300 ° C to 1500 ° C, the placeholder element or the placeholder elements are thermally decomposed, e.g.
  • the thermally decomposable placeholder element (s) are only arranged in the core core and not in the core shell, the core shell or the casting core has a dense and mechanically solid surface which is suitable for contact with the melt in the Casting process is suitable, which is why the casting core remains dimensionally stable during the casting process.
  • the functionality of the material composition in the different core areas can be adapted to the opposite requirements.
  • fillers or ceramic particles can be used in the jacket, which have a low interaction with the melt.
  • a lower porosity and higher mechanical strength can be provided in the core jacket.
  • the thermal properties can be selected by the fillers used in the core jacket so that, depending on the casting temperature and the amount of heat input, the core soul is destabilized at different times. This decoupling enables high process reliability and good casting quality to be achieved.
  • the thermally decomposable placeholder element (s) reduce the amount of inorganic fillers or ceramic particles that may have to be disposed of and reduce the weight of the cores.
  • a preferred embodiment of the casting core according to the invention is characterized in that the ceramic particles of the core shell and / or the ceramic particles of the core core are selected from the group consisting of quartz sand particles, zircon sand particles, aluminosilicate particles, mullite particles, inorganic hollow spheres, alumina particles and mixtures thereof.
  • the thermal properties can be influenced in such a way that, depending on the casting temperature and the amount of heat input, the core soul is destabilized at different times.
  • the speed of the temperature rise in the core core and thus the beginning of the destruction of the material cohesion in the core core can be set in this way via the thermal properties of the core shell.
  • the ceramic particles of the core shell and / or the ceramic particles of the core core have an average particle diameter of 0.5 miti to 500 miti. The average particle diameter can be determined, for example, by means of laser diffraction.
  • binder of the core shell and / or the binder of the core core is selected from the group consisting of
  • inorganic binders preferably silicate binders, e.g.
  • a further preferred embodiment of the casting core according to the invention is characterized in that the placeholder element (s) from (or at) a temperature in the range from 300 ° C. to 1500 ° C., preferably from (or at) a temperature in the range of 400 ° C to 1400 ° C, preferably from (or at) a temperature in the range from 500 ° C to 1300 ° C, is / are at least partially thermally decomposable.
  • the placeholder element (s) is / are at least partially thermally decomposable from a temperature in a range of 300 ° C. to 1500 ° C. is to be understood in such a way that the placeholder element (s) are separated any temperature in the range of 300 ° C to 1500 ° C decomposed or partially decomposed.
  • the placeholder element or the placeholder elements can decompose from a temperature of 800 ° C, which means that the placeholder element or the placeholder elements can / are thermally decomposable at a temperature> 800 ° C.
  • Thermal decomposition can e.g. a burnout, e.g. a partial burnout or a residue-free burnout of the placeholder element or the placeholder elements.
  • the placeholder element (s) is / are preferably thermally decomposable or (completely) thermally decomposable from (or at) a temperature in the range from 300 ° C. to 1500 ° C. It is also possible for the placeholder element (s) to be thermally decomposable over the entire temperature range from 300 ° C. to 1500 ° C.
  • the placeholder element (s) can be burned out, preferably can be burned out without residue.
  • the placeholder element (s) is / are selected from the group consisting of wood foam elements
  • Polymer foam elements Polystyrene beads, polymer granules and mixtures thereof.
  • the core core consists of the ceramic particles bound with the binder and the placeholder element (s).
  • a further preferred embodiment is characterized in that the core jacket and the core core have pores with an average pore size of 1 pm to 50 pm, the core jacket having a lower porosity than the core core.
  • the average pore size and / or the porosity can e.g. are determined by means of mercury porosimetry.
  • the core jacket has a thickness of 3 mm to 15 mm, preferably 3 mm to 10 mm, particularly preferably 3 mm to 7 mm.
  • the speed of the temperature rise in the core core and thus the beginning of the destruction of the material cohesion in the core core can be set via the thickness of the core shell. This ensures increased pressure resistance of the core during mold filling and destabilization of the core after sufficient heat input into the core.
  • the core core has a diameter of 5 mm to 100 mm, preferably 10 mm to 100 mm, particularly preferably 15 mm to 100 mm.
  • the present invention also relates to a method for producing a casting core according to the invention, in which
  • the placeholder element (s) (preferably from or at a temperature in the range from 300 ° C. to 1500 ° C.) is / are at least partially thermally decomposable
  • the dried core core of the casting core is inserted into a second casting mold, which has the negative contour of the casting core to be produced, and then a second aqueous, ceramic suspension, which comprises ceramic particles, a binder and water, is poured into this second casting mold becomes,
  • the second ceramic suspension located in the second casting mold is solidified to form a core shell of the casting core
  • the casting core comprising the core core and the core shell is removed from the second casting mold and then dried.
  • inorganic binders based on gypsum, cement, phosphate or silica can be used. Binder based on water glass can be gassed with carbon dioxide after shaping. The water glass reacts with the formation of colloidal silica and sodium carbonate and this strengthens the suspension to the corresponding part of the casting core. In suspensions with water glass or colloidal silica sol as a binder, a solidification can also be obtained by shifting the pH to the neutral range (for example by adding an acid) or drying. After shaping, excess water and bound water, which can be split off at the required casting temperature of the molten metal and which could impair the casting quality, must be removed. This is done by drying. If the required drying temperature is higher than the temperature resistance of the placeholder elements used, partial thermal decomposition of the placeholder elements begins when drying and the porosity or instability in the core core is increased.
  • Drying in steps c) and f) is preferably carried out at a temperature from 50 ° C. to 300 ° C., particularly preferably from 90 ° C. to 200 ° C., and / or over a period of 0.1 to 10 hours, preferably from 0.5 to 5 hours, particularly preferably from 1 to 3 hours. Drying can be carried out over several steps, for example a low temperature being selected in the first drying step and a higher temperature being selected in the second drying step.
  • the dried core core is preferably provided with core brands (for positioning the core core in the second mold).
  • the core brands then allow the exact positioning of the core core within this second mold when the dried core core of the casting core is inserted into the second casting mold, so that the core core later has the desired position in the finished casting core.
  • a preferred variant of the method according to the invention is characterized in that in step a) a mixture of a first aqueous, ceramic suspension which comprises ceramic particles, a binder and water, and a plurality of placeholder elements, preferably polystyrene beads, are produced. is set and the mixture is then poured into a first casting mold, which has the negative contour of a core core of the casting core to be produced.
  • a further preferred variant of the method according to the invention is characterized in that in step a) a mixture of a first aqueous ceramic suspension comprising ceramic particles, a binder and water, and a placeholder element, preferably a wood foam element or a polymer foam element , is produced in a first casting mold, which has the negative contour of the core core of the casting core to be produced, with the placeholder element first being cut into the shape of the core core and placed in the first casting mold and then the placeholder element with the first aqueous, ceramic Suspen sion is infiltrated and / or cast.
  • the present invention also relates to the use of a casting core according to the invention in a method for casting one or more components.
  • a core mass based on a phosphate binder is produced as follows: 60% "Wirovest" phosphate binder (BEGO) and 40% quartz powder are stirred into water until a flowable consistency is obtained.
  • a reticulated foam (polyether-based dryfeel, pore size 15 ppi , Eurofoam) is cut in the form of the core core, inserted into a mold and infiltrated with the core material produced and cast. After the beginning of solidification, the component is removed from the mold.
  • the core core is dried (at 90 ° C. to remove excess water, then at 180 ° C for one hour) and inserted in a divisible form that reflects the geometry of the core.
  • the core core is cast with the core mass. After solidification and After demolding, the core is dried at a temperature of 180 ° C for one hour.
  • Polystyrene beads are stirred into a ceramic mass consisting of 88.5% phosphate binder "Wirovest” (BEGO) and 11.5% demineralized water and poured into a mold for the core core.
  • the hardened component is shaped and divided into parts Insert the core mold and cast the following ceramic mass: 40% mullite (Symulox M72 K0, Nabaltec, average particle size between 7-15 pm) and 60% phosphate binder "Wirovest” (BEGO) are stirred into water until a flowable mass is obtained. After solidification, the core is removed from the mold and dried at 100 ° C.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Materials Engineering (AREA)
  • Mold Materials And Core Materials (AREA)
  • Molds, Cores, And Manufacturing Methods Thereof (AREA)

Abstract

La présente invention concerne un noyau de coulée pour moules de fonderie, le noyau de coulée comportant une âme et une enveloppe disposée tout autour de l'âme. L'enveloppe du noyau contient des particules de céramiques liées par un liant ou en est constitué. L'âme de noyau contient des particules de céramique liées par un liant et, en plus, au moins un élément de réservation de place. Le/les éléments de réservation de place est/sont au moins en partie thermiquement décomposables. La présente invention concerne également un procédé de fabrication du noyau de coulée selon l'invention ainsi que l'utilisation du noyau de coulée selon l'invention.
EP19773055.9A 2018-09-19 2019-09-19 Noyau de coulée pour moules de fonderie et procédé de fabrication Pending EP3852951A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE102018215957.2A DE102018215957A1 (de) 2018-09-19 2018-09-19 Gießkern für Gießformen sowie Verfahren zu dessen Herstellung
PCT/EP2019/075170 WO2020058402A1 (fr) 2018-09-19 2019-09-19 Noyau de coulée pour moules de fonderie et procédé de fabrication

Publications (1)

Publication Number Publication Date
EP3852951A1 true EP3852951A1 (fr) 2021-07-28

Family

ID=67999656

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19773055.9A Pending EP3852951A1 (fr) 2018-09-19 2019-09-19 Noyau de coulée pour moules de fonderie et procédé de fabrication

Country Status (5)

Country Link
US (1) US11590564B2 (fr)
EP (1) EP3852951A1 (fr)
CN (1) CN112739476B (fr)
DE (1) DE102018215957A1 (fr)
WO (1) WO2020058402A1 (fr)

Family Cites Families (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3568723A (en) * 1967-06-23 1971-03-09 Du Pont Metal-ceramic composite structures
FR1584065A (fr) * 1968-07-30 1969-12-12
DE19918908A1 (de) * 1999-04-26 2000-11-02 Fraunhofer Ges Forschung Kern für in Gußtechnik hergestellte Bauteile und Herstellverfahren dazu
DE10327272A1 (de) 2003-06-17 2005-03-03 Generis Gmbh Verfahren zum schichtweisen Aufbau von Modellen
US8540009B2 (en) * 2009-02-23 2013-09-24 GM Global Technology Operations LLC Hollow sand cores to reduce gas defects in castings
CN101716650A (zh) * 2009-12-17 2010-06-02 浙江红马铸造有限公司 一种复合型泥芯及其制作方法
JP2013071169A (ja) 2011-09-29 2013-04-22 Hitachi Ltd 精密鋳造用セラミック中子と、その製造方法
JP6141539B2 (ja) 2013-10-19 2017-06-07 ピーク ドイチュラント ゲゼルシャフト ミット ベシュレンクテル ハフツングＰｅａｋ Ｄｅｕｔｓｃｈｌａｎｄ ＧｍｂＨ 鋳造品製造のためのロストコア又は成形品を製造する方法
CA2885074A1 (fr) * 2014-04-24 2015-10-24 Howmet Corporation Noyau cru en ceramique produit au moyen de la fabrication additive
CN104550756B (zh) * 2014-12-26 2017-01-18 中核苏阀横店机械有限公司 管模砂型芯
DE102016119399A1 (de) * 2015-10-16 2017-04-20 Ksm Castings Group Gmbh Gießkern für ein Pumpengehäuse, insbesondere für ein Gehäuse einer Hochdruckpumpe
CN107052254A (zh) * 2016-11-30 2017-08-18 安徽应流集团霍山铸造有限公司 一种增强其芯砂退让性和溃散性的一种技术装置

Also Published As

Publication number Publication date
WO2020058402A1 (fr) 2020-03-26
US11590564B2 (en) 2023-02-28
CN112739476A (zh) 2021-04-30
CN112739476B (zh) 2023-03-28
US20210213514A1 (en) 2021-07-15
DE102018215957A1 (de) 2020-03-19

Similar Documents

Publication Publication Date Title
DE102004042535B4 (de) Formstoffmischung zur Herstellung von Gießformen für die Metallverarbeitung, Verfahren und Verwendung
EP2097192B2 (fr) Mélange de matières de moulage à base de phosphore, utilisé pour produire des moules pour la transformation de métaux
DE19621638C2 (de) Offenzellige Schaumkeramik mit hoher Festigkeit und Verfahren zu deren Herstellung
DE10317473B3 (de) Keramische Gussformen für den Metallguss und deren Herstellungsverfahren
EP1633509B1 (fr) Procede de realisation de modeles par couches
EP3478427A1 (fr) Particules c ur-écorce destinées à être utilisées comme charge dans des matières pour masselottes
DE102004056012B4 (de) Verfahren zur Herstellung eines keramischen Formteils mit einer dreidimensionalen Netzstruktur
EP3852951A1 (fr) Noyau de coulée pour moules de fonderie et procédé de fabrication
DE102008056842A1 (de) Gießereikerne mit verbesserten Entkernungseigenschaften II
EP2853320A1 (fr) Moule ou noyau de moule en sable de moulage revêtu pour coulée métallique
EP3852949A1 (fr) Noyau de coulée pour moules de coulée et son procédé de fabrication
DE10332367B4 (de) Verfahren zur Herstellung von metallischen Gussteilen mittels des Vollformgießens
EP0958260B1 (fr) Procede de fabrication de composants de ceramique ou de metallurgie des poudres
DE10216403B4 (de) Aerogelgebundene Formstoffe mit hoher Wärmeleitfähigkeit
DE4442884B4 (de) Verfahren zur Herstellung eines Formkörpers
DE102012110258A1 (de) Verfahren zur Herstellung eines Zylinderkurbelgehäuses
WO2020058393A1 (fr) Noyau de coulée pour moules de coulée et son procédé de fabrication
DE19703176C2 (de) Verfahren zur Herstellung von keramischen oder pulvermetallurgischen Bauteilen
DE10245010B4 (de) Keramische Einbettmasse
WO2023020905A1 (fr) Barbotine céramique destinée à la coulée de précision basée sur une suspension capillaire
DE102005011019A1 (de) Herstellung und Verwendung eines zerstörbaren Formkerns für den metallischen Guss
DE10135358A1 (de) Verfahren zur Herstellung eines Bauteils mit einem Metall-Keramik-Verbundwerkstoff
DE102004021209B4 (de) Verfahren zur Herstellung einer Gießform aus einem Verbundformstoff für Gießereizwecke
DE102006022594A1 (de) Formwerkzeug zur Herstellung eines Schaumteiles und Verfahren zur Herstellung des Formwerkzeuges
WO2008077726A1 (fr) Procédé de fabrication d'une coquille de moule en ceramique et utilisation de celle-ci.

Legal Events

Date Code Title Description
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: UNKNOWN

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE INTERNATIONAL PUBLICATION HAS BEEN MADE

PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE

17P Request for examination filed

Effective date: 20210309

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

DAV Request for validation of the european patent (deleted)
DAX Request for extension of the european patent (deleted)
RAP3 Party data changed (applicant data changed or rights of an application transferred)

Owner name: FRAUNHOFER-GESELLSCHAFT ZUR FOERDERUNG DER ANGEWANDTEN FORSCHUNG E.V.