Classifications

• • 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
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22C—FOUNDRY MOULDING
  • B22C9/00—Moulds or cores; Moulding processes
  • B22C9/02—Sand moulds or like moulds for shaped castings
  • B22C9/04—Use of lost patterns
• • 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
  • B22C1/02—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by additives for special purposes, e.g. indicators, breakdown additives
  • B22C1/04—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by additives for special purposes, e.g. indicators, breakdown additives for protection of the casting, e.g. against decarbonisation
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
  • F01D25/00—Component parts, details, or accessories, not provided for in, or of interest apart from, other groups
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
  • F01D25/00—Component parts, details, or accessories, not provided for in, or of interest apart from, other groups
  • F01D25/005—Selecting particular materials
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
  • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
  • F05D2230/00—Manufacture
  • F05D2230/20—Manufacture essentially without removing material
  • F05D2230/21—Manufacture essentially without removing material by casting
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
  • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
  • F05D2300/00—Materials; Properties thereof
  • F05D2300/10—Metals, alloys or intermetallic compounds
  • F05D2300/13—Refractory metals, i.e. Ti, V, Cr, Zr, Nb, Mo, Hf, Ta, W
  • F05D2300/133—Titanium

Definitions

• Tool for producing cast components method for producing the tool and method for producing cast components
• the invention relates to a tool for producing cast components according to the preamble of patent claim 1. Furthermore, the invention relates to a method for producing such a tool according to the preamble of patent claim 6 and a method for producing a cast component according to the preamble of patent claim 11.
• the present invention relates to the production of components, in particular gas turbine components, from non-ferrous metal melts, in particular titanium-aluminum alloys, in particular those with 43-48% by weight of aluminum, which form an intermetallic phase with the aid of a casting process.
• molds so-called molds
• the molds having an inner contour that corresponds to the outer contour of the component to be produced.
• a distinction is made between casting processes that work with lost casting molds or permanent casting molds.
• casting processes that work with lost molds only one component can be produced with one mold.
• the casting molds can be used several times in casting processes that work with permanent casting molds.
• the casting processes that work with lost molds include the so-called investment casting.
• mold casting for the casting processes that work with permanent casting molds, reference is made here to mold casting as an example.
• the present invention relates in particular to so-called investment casting.
• State-of-the-art investment casting molds made from highly refractory ceramics are used. To produce a casting mold for the investment casting, roughly the procedure is followed in such a way that in a first step a model is made available for the casting component that will later be produced with the casting mold, the model having a similar shape to the casting component to be produced, but by the shrinkage of the Cast material larger dimensions.
• This model is also called a component wax.
• this component wax is preferably coated several times with a slip material and sanded and optionally backfilled subsequently, so that after the melting of the component wax, the mold is either in the so-called compact shape or in the so-called shell shape. After the component wax has melted out, the resulting one-piece mold is fired. The still molten metal of the cast component to be produced can then be poured into the preferably still hot mold, the cast component being knocked out of the mold after solidification. The mold is lost.
• the casting molds according to the prior art are formed from highly refractory ceramic materials, such as aluminum oxide, zirconium oxide or yttrium oxide with additions of silicon dioxide.
• a corresponding slip material is applied to a component wax using a slip process according to the prior art.
• Casting molds that contain silicon dioxide admixtures are reactive and lead to surface defects in the production of cast components from reactive non-ferrous metal melts, such as titanium alloys or titanium-aluminum alloys. This can lead to surface defects, dimensional deviations, cracks and the formation of so-called voids on the cast component to be produced.
• the casting molds known from the prior art are therefore not suitable for reactive nonferrous metal melts.
• the present invention is based on the problem of creating a novel tool for producing cast components, a method for producing such a tool, and a method for producing a cast component.
• At least one area of the casting mold that comes into contact with the reactive nonferrous metal melt consists of yttrium oxide, magnesium oxide and calcium oxide.
• the casting mold has an at least two-layer structure, a first layer forming a mold wall region coming into contact with the reactive non-ferrous metal melt and a second layer forming a stabilization region behind the mold wall region. Both the first layer and the second layer consist of yttrium oxide, magnesium oxide and calcium oxide, the second layer, which backfills the first layer, has less yttrium oxide and is coarser than the first layer.
• the inventive method for producing such a tool is characterized by the features of the independent claim Patent.
• the method for producing a cast component is defined in claim 1 1.
• FIG. 1 shows a cross section through a mold according to the invention for a gas turbine blade together with a gas turbine blade produced by casting.
• FIG. 1 shows a cross section through a mold 10 together with a gas turbine blade 1 1 produced by casting, the gas turbine blade 1 1 comprising an airfoil 12 and a blade root 13.
• the gas turbine blade 11 produced by casting is surrounded by the mold 10.
• the casting mold is formed in two layers.
• a first layer 14 of the casting mold 10 forms a mold wall covering which comes into contact with the reactive non-ferrous metal melt of the cast component to be produced. rich, a second layer 15 thereof forms a backfill for the first layer 14.
• At least the first layer 14 of the casting mold 10 which comes into contact with the reactive non-ferrous metal melt of the gas turbine blade 1 1 to be produced, consists of yttrium oxide, magnesium oxide and calcium oxide.
• a composition of the casting mold 10 at least in the area of the first layer 14, reactions between the casting mold and the reactive non-ferrous metal melt are avoided, so that dimensional deviations and crack formation on the cast component to be produced, namely on the gas turbine blade 1 1 to be produced, are avoided.
• the second layer 15 of the casting mold 10 consists of yttrium oxide, magnesium oxide and calcium oxide.
• the second layer 15 forming the backfill has a significantly lower yttrium oxide content than the first layer 14, which comes into contact with reactive non-ferrous metal melt of the gas turbine blade 11 to be produced.
• the second layer 15 is coarse-grained and thick-walled than the first layer 14. This is particularly advantageous for reasons of cost and manufacturing.
• the procedure according to the invention is such that a component wax is provided which has approximately the geometric dimensions of the casting component to be produced with the casting mold.
• the component wax is coated with a slip material, the slip material consisting of water, yttrium oxide, magnesium oxide and calcium oxide.
• the mold 10 to be produced is formed in two layers. Accordingly, in a first step of the method according to the invention for producing the mold 10 shown in FIG. 1, the component wax is preferably first coated in multiple layers with the slip material such that the first layer 14 of the mold is formed. Only then does the preferably multilayer coating of the first layer 14 take place with the second Layer 15, the second layer 15 forming the backfill for the first layer 14. Correspondingly coordinated slip materials are provided for the production of the first layer 14 and the second layer 15, both slip materials consisting of water, yttrium oxide, magnesium oxide and calcium oxide. However, the slip material for forming the second layer has a lower yttrium oxide content and is of a coarser grain than the slip material for forming the first layer 14.
• the yttrium oxide and the magnesium oxide prevent an undesirable reaction of the non-ferrous metal melt of the cast component to be produced with the mold 10.
• the magnesium oxide together with the water of the slip material, causes an exothermic reaction in which the water is evaporated. This significantly reduces the drying time of the layers 14 and 15 of the casting mold 10.
• the slip material sets like concrete.
• the firing temperature for the mold can be reduced from approx. 1400 ° C to approx. 900 ° C, whereby the casting temperature is also approx. 900 ° C. This enables the production of the molds in a quick, simple and inexpensive manner.
• the thin, first layer 14 suppresses undesirable reactions between the mold and the non-ferrous metal melt.
• the second layer 15 brings about a sufficient mechanical strength of the casting mold and gives it a high heat capacity, which enables slow cooling of the casting mold and a casting temperature of approximately 900 ° C.
• the mechanical strength minimizes shrinkage, the high heat capacity causes microplastic deformability of the otherwise brittle material to be processed by casting, so that no component cracks or breaks occur.
• the mold can be filled by centrifugal casting.
• centrifugal casting it is advantageous to use heatable molds by means of microwave radiation or inductive coupling.
• metal particles, metallic structures, in particular metal networks, and semiconducting and conductive non-metals, in particular graphite or silicon can be embedded in the layer (s) of the mold.
• the casting mold 10 with a changing thickness, in particular in the area of the second layer 15. 1 shows that the second layer 15 is formed much thicker in the area of the blade root 13 than in the area of the airfoil 11.
• the thickness of the casting mold can additionally be varied by virtue of the fact that the casting mold is thinner at the upper end of the airfoil 12 than in the lower region, which adjoins the blade root 13. In this way it can be achieved that the non-ferrous metal melt solidifies in a directed manner and the solidification front ends in the region of the blade root.
• the casting mold according to the invention is particularly suitable for the production of gas turbine components such as blades, which are produced from a titanium-aluminum alloy, in particular titanium aluminides with 43-48% aluminum, which form intermetallic phases.
• a titanium-aluminum alloy melt is poured into the casting mold described above, the casting component being detached from the casting mold after solidification.

Landscapes

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

Priority Applications (1)

Applications Claiming Priority (2)

Related Child Applications (1)

Publications (1)

Family

ID=34399396

Family Applications (2)

Family Applications After (1)

Country Status (7)

Families Citing this family (23)

Family Cites Families (14)

• 2003
  • 2003-10-09 DE DE10346953A patent/DE10346953A1/de not_active Ceased
• 2004
  • 2004-09-23 KR KR1020067006934A patent/KR100801970B1/ko not_active Expired - Fee Related
  • 2004-09-23 WO PCT/DE2004/002106 patent/WO2005039803A2/de not_active Application Discontinuation
  • 2004-09-23 JP JP2006529615A patent/JP4818113B2/ja not_active Expired - Fee Related
  • 2004-09-23 US US10/574,660 patent/US7389809B2/en not_active Expired - Lifetime
  • 2004-09-23 CN CNA2004800295572A patent/CN1863621A/zh active Pending
  • 2004-09-23 EP EP04786823A patent/EP1670602A2/de not_active Ceased
  • 2004-09-23 EP EP09168304A patent/EP2113318A3/de not_active Ceased

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events