Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
  • B22D17/00—Pressure die casting or injection die casting, i.e. casting in which the metal is forced into a mould under high pressure
  • B22D17/20—Accessories: Details
  • B22D17/22—Dies; Die plates; Die supports; Cooling equipment for dies; Accessories for loosening and ejecting castings from dies
  • B22D17/2209—Selection of die materials
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
  • C23C22/05—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions
  • C23C22/06—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6
  • C23C22/34—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6 containing fluorides or complex fluorides
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
  • C23C22/73—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals characterised by the process
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
  • C23C22/73—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals characterised by the process
  • C23C22/74—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals characterised by the process for obtaining burned-in conversion coatings
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
  • C23C22/73—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals characterised by the process
  • C23C22/77—Controlling or regulating of the coating process

Definitions

• the invention relates to a metallic, iron-containing permanent mold with a coating which can be acted upon by a liquid or a flowable aluminum material. Moreover, the invention relates to a release agent for producing such a layer, and to a method for producing such a layer on a surface of a permanent mold.
• release agents for trouble-free operation.
• various requirements set forth below are imposed on the release agents used in the process.
• the release agent must serve to assist the metal flow, resulting in a uniform filling of the permanent mold and at the same time the release agent is used to improve the final formability of the cast parts.
• the release agent serves to avoid residues on the permanent mold, which can lead to inaccuracies in the form.
• the release agent During the pouring of the material into the permanent mold, no excessive gas formation may occur during the decomposition of the release agent, which would lead to a porosity of the molded parts.
• the release agent must ultimately contain no dangerous or toxic substances. Depending on the fulfillment of these requirements, the quality of the release agent is measured.
• boron nitride A long known and used in release agents material is boron nitride (BN), which is similar in structure to its crystal structure as graphite. Like graphite, it has a low wettability compared to many substances, such as silicate melts or molten metals. Therefore, there are many studies on non-adherent layers based on boron nitride in order to use them for casting processes. The problem with this use, however, is that it is not possible to permanently apply boron nitride to forms, in particular of a complex nature.
• a method for permanent application of a temperature-stable, corrosion-resistant mold release layer is in DE 198 42 660 A1 described. Here, a boron nitrite powder is applied by means of electrostatic coating on the surface of a permanent mold.
• a wear protection layer is known, are integrated in the functional materials in a binder matrix.
• This so-called functional coating consists of an inorganic matrix phase, which consists at least largely of a phosphate, and a functional material embedded therein, for example, a metal, graphite, a hard material, a dry lubricant, a Alumina, a silicon carbide, etc. may be.
• a liquid component which may be, for example, water, a functional material in powder form and is added to produce a phosphate with phosphoric acid.
• Such a composite matrix solution with the liquid component and the phosphate may also be referred to as gel due to their consistency.
• the material After coating a material with this matrix solution, the material undergoes a heat treatment, so that a firmly adhering functional coating is formed on the base material.
• the object of the present invention is to develop a long-term stable layer on a metallic, iron-containing permanent form, which enters into a chemical bond with the base material of Treasureform and thus meets the requirements for a release agent or even goes beyond these requirements, by casting errors by the Formation of oxide skins during the casting process can be avoided. Moreover, it is an object of the invention to provide a release agent for producing such a layer, which is inexpensive to produce and easy to apply without the expense of equipment. Another object of the invention is to provide a method capable of producing such a layer and by means of Damage to the layer are easily healed.
• the requirements for a release agent in the form of a long-term stable layer are particularly well met.
• the metal flow is supported to the effect that the oxide skin of the aluminum material is broken up by the structural parts protruding from the layer and the liquid aluminum material can easily be distributed in the permanent form below the oxide layer.
• the layer thus offers optimum conditions for filling the permanent mold.
• the sliding parts of the form boron nitride (BN) serve as a sliding surface for the liquid or flowable aluminum and thus support the metal flow, they also serve at the same time to improve the Endform Marie of the cast components.
• a firmly adhering layer is formed, wherein the solid composite is produced by the chemical bonding of the fluorides with the iron of the permanent material of the permanent mold.
• This type of firm bonding of the layer with the base material of the permanent form prevents residues from adhering to the permanent mold, which could lead to dimensional inaccuracies.
• Another advantage of the layer according to the invention is that the layer is excited at elevated temperatures to an increased polymerization. As a result, longer polymers form, on the one hand increase the adhesion and cohesion and on the other hand increase the elasticity of the layer.
• the long-term stable and firmly adhering layer is therefore extremely elastic at higher temperatures, as occur during filling of the permanent mold, and can follow the changes in shape of the permanent mold elastically and thus advantageously without damage to the layer.
• the release agent according to the invention offers the advantage that it can be produced cost-effectively on the basis of demineralized water and, on the other hand, is easy to apply to the tool due to its viscosity. in the simplest case, the release agent can be sprayed on the permanent mold. In addition, the release agent meets the requirements for a release agent in that no toxic substances are included, which can be disposed of only at high cost.
• the object according to the invention with regard to the method for producing a layer is achieved in that the surface is first subjected to the release agent according to one of claims 6 to 13, and that subsequently the permanent mold is heated to a temperature of at least 200 ° C.
• the fluoride chemically bonds with the iron of the base material and the zirconium fluoride forms polymers which form a firmly adhering layer on the surface of the permanent mold.
• the advantage here is that the release agent, which consists of a completely desalinated water, at this temperature is already completely evaporated from the layer and thus there is no or very little gas formation when filling the permanent mold.
• the polymerization is supported in increasing the temperature, so that as described above, another advantageous effect of the layer is generated.
• the use of gelatin is particularly advantageous since this nanoparticles are formed independently.
• the layer is very easy to heal, since defects in the layer are immediately lashed out after a renewed application of the permanent mold with the release agent.
• new iron fluoride is formed and by the temperature of the permanent form zirconium fluoride polymerizes, so that the layer completely heals.
• a layer is formed which has a thickness of about 1 to 80 .mu.m, layer thicknesses between 30 and 50 .mu.m are preferred, but this in turn Deployment case is dependent.
• the layer thickness is dependent on the application, that is, on the casting process, wherein the thinnest layers are used for die casting and the thickest layers for low pressure. During die casting, the thinnest layers are applied, since here a good heat transfer to the permanent mold is deliberately set, in order to allow rapid solidification of the casting. In the combined so-called squeeze-casting process, an average thickness is set, since in this case the casting mold is slowly filled and then subjected to a high pressure.
• the existing on the surface of the permanent mold layer is chemically connected by means of the iron fluoride with the base material.
• the iron fluoride thus acts as an adhesive between the layer and the base material.
• the structural parts of the form Al 2 O 3 and / or SiO 2 and / or TiO 2 and / or ZrO 2 have a size of about 80 nm until 200nm and hook against each other and form a layer on the base material.
• the term structural parts is selected specifically, since particles are preferably used which are not smooth but have a structured surface.
• the primary parts of the form Al 2 O 3 and / or SiO 2 and / or zinc oxide and / or titanium dioxide and / or zirconium dioxide and / or cerium oxide, which are present in a size of 1 nm to 10 nm, preferably and very easy.
• the much larger sliding parts of the boron nitrite lie between the structural parts in the layer and are held by the composite of structural parts with polymers. Because of its fractile structure, the layer thus constructed has a self-interlocking effect, but the essential bond between the iron fluoride and the structural parts, the primary parts and the sliding parts is created by the polymerized zirconium fluoride.
• the chains of the polymers provide the cohesion between the chemically bound iron fluoride, the structural parts, the primary parts and the sliding parts.
• the polymers used according to the invention polymerize at about 200 ° C. and have a glazing temperature of about 830 ° C.
• the liquid aluminum has a temperature of about 730 ° C and thus does not reach the glazing temperature of the polymers. It is thus an extremely stable, created for the casting of aluminum materials very suitable system as a layer structure.
• the iron fluorides serve as an adhesive to the base material of the permanent mold and the primary parts are advantageously used to close the gaps between the structural cells, thus producing a very smooth surface. An adhesion of the liquid casting material is thus almost almost impossible.
• the Structural parts are available in a size of 80nm to 200nm and stand out as edges from the layer.
• the structurally highly structured structural parts tear cracks in the oxide layer of the liquid aluminum and grind the oxide skin, so that the oxide skin is crushed into minute parts and thus not present as lattice defects in the structural structure of the casting.
• An advantage of the structural parts used according to the invention is thus that the oxide skin is destroyed and comminuted.
• the sliding parts which are in the form of boron nitride, are much larger in size than the primary and structural parts.
• the structural parts form the structural parts with a weight percentage of up to 10% in the liquid release agent, the largest part of the layer.
• the primary parts serve as fillers for the interstices and thus serve to smooth the layer.
• the sliding parts present in a proportion by weight of up to 5%, are finely distributed in the structural parts and also occur on the surface of the layer. Due to the number of sliding parts, these do not form the largest surface of the layer but are very finely distributed, so that they serve as a lubricant for a casting but primarily for demolding the permanent mold and for removing the casting.
• the removal from the mold is advantageously facilitated by the use of the layer according to the invention, since, on the one hand, a very smooth surface is present on the layer through the structural parts and the smoothing primary parts and, at the same time, a lubricant is provided by the sliding parts.
• the zirconium fluoride polymerizes and a long-term stable layer is formed on the surface of the permanent mold.
• a usual temperature for preheating during die casting is a temperature between 220 ° C and 280 ° C, so that here an optimum temperature for the polymerization of the release agent is present.
• the preheating temperatures are still above 300 ° C, so that a layer is also formed here.
• the liquid metal at a temperature of about 720 ° C to 730 ° C when casting aluminum is below the glass transition temperature. But the Thixocasting is above 200 ° C and thus the use of the layer according to the invention in this method is also conceivable.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• General Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Mold Materials And Core Materials (AREA)
• Lubricants (AREA)
• Molds, Cores, And Manufacturing Methods Thereof (AREA)
• Compositions Of Macromolecular Compounds (AREA)

Applications Claiming Priority (2)

Publications (2)

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• 2006
  • 2006-03-07 DE DE102006010876A patent/DE102006010876A1/de not_active Withdrawn
• 2007
  • 2007-02-15 KR KR1020087023899A patent/KR20080111027A/ko not_active Ceased
  • 2007-02-15 CN CN2007800137873A patent/CN101500729B/zh not_active Expired - Fee Related
  • 2007-02-15 EP EP07722819.5A patent/EP1993755B1/de not_active Not-in-force
  • 2007-02-15 WO PCT/EP2007/001300 patent/WO2007101528A1/de not_active Ceased
  • 2007-02-15 JP JP2008557613A patent/JP4779025B2/ja not_active Expired - Fee Related
  • 2007-02-15 BR BRPI0708651-2A patent/BRPI0708651A2/pt not_active Application Discontinuation
• 2008
  • 2008-09-05 US US12/205,311 patent/US8403024B2/en not_active Expired - Fee Related

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