EP1464716B1 - Quasicrystalline Ti-Cr-Al-Si-O alloy and its use as a coating - Google Patents

Quasicrystalline Ti-Cr-Al-Si-O alloy and its use as a coating Download PDF

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EP1464716B1
EP1464716B1 EP04101277A EP04101277A EP1464716B1 EP 1464716 B1 EP1464716 B1 EP 1464716B1 EP 04101277 A EP04101277 A EP 04101277A EP 04101277 A EP04101277 A EP 04101277A EP 1464716 B1 EP1464716 B1 EP 1464716B1
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sio
compound
range
coating
sample
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German (de)
French (fr)
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EP1464716A8 (en
EP1464716A1 (en
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Valery Dr. Shklover
Maxim Dr. Konter
Anton Dr. Kaiser
Kenneth Franklin Prof. Dr. Kelton
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General Electric Technology GmbH
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Alstom Technology AG
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    • 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
    • C23C4/00—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge
    • C23C4/04—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge characterised by the coating material
    • C23C4/06—Metallic material
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
    • C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
    • C22F1/16—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of other metals or alloys based thereon
    • C22F1/18—High-melting or refractory metals or alloys based thereon
    • C22F1/183—High-melting or refractory metals or alloys based thereon of titanium or alloys based thereon
    • 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
    • C23C28/00—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
    • 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
    • C23C30/00—Coating with metallic material characterised only by the composition of the metallic material, i.e. not characterised by the coating process

Definitions

  • the present invention relates to quasi-crystalline or approximant Compounds, a process for their preparation and uses of such Compounds in particular in connection with the coating of heat exposed components.
  • An approximant is a chemical structure of similar composition to that of the associated quasicrystal, wherein the approximant periodic structures with very large unit cells and very similar local order as those of the corresponding one Quasicristalls has.
  • the approximant is referred to in this context as ⁇ (TiCrSiO) or 1/1 phase, this is the most important phase in these examined alloys.
  • Neutron studies show that the oxygen atoms at which octahedral positions are arranged, probably a bond to the titanium atoms present. Thus, based on energy bills, the existence suspected of a network of octahedrons.
  • the titanium-based quasicrystalline materials can be classified as metallic Alloys with internal ceramic layers are considered.
  • the thermal conductivity of quasicrystalline alloys and their Approximants in which only long-wave phonons can propagate are lower than those of typical metal alloys. This was for example in the following Publications: P. Archambault, P. Plaindoux, E. Belin-Ferre and J.M. Dubois: Thermal and Electronic Properties of AlCoFrCr Approximant of the Decagonal Phases, Quasicrystals, MRS, 535, 409 (1999); J.M. Dubois: New Prospects From Potential Applications of Quasicrystal Materials, Mat. Sc. and Engineering, 294-296, 4 (2000).
  • the thermal conductivity of exclusively aluminum-based Quasicrystal alloys (or their approximants) are also studied Service.
  • Icosahedral, quasi-crystalline alloys of the Ti 68-x Cr 32 Si x type with 6 ⁇ x ⁇ 18 are disclosed by Zhang, X.; Kelton, KF, "Icosahedral phase formation in Ti 68-x Cr 32 Si x alloys" Philosophical Magazine Letters, 1990, Vol. 62, No.4, 265-271, 1990.
  • connection should have advantageous properties, as in particular in connection with the use as a coating of components flowed around by hot gases, which are used for example in gas turbines, are required. So shall the Connection respectively the class of connections a corresponding strength respectively strength and density, is said to have a low thermal conductivity as far as possible also constitute a diffusion barrier for oxygen, a have high stability with respect to oxidation, and possibly the Observation of diffusion reactions between the compound and the material, on which the compound is applied allow.
  • the atomic percentage of oxygen is in the range of 8-20%, preferably 8 to 15%. Below this content, the desired structure is not formed, and above forms an oxide phase.
  • the atomic percentage of aluminum is advantageously adjusted to a range of 2 to 5%. Of course, corresponding combinations of such materials are conceivable.
  • the core of the invention thus consists of the usual strength for titanium alloys and density, as well as the low thermal conductivity of quasicrystalline alloys.
  • the ceramic allow Interlayers prevent diffusion through the layer (Diffusion barrier).
  • the proposed compounds also have improved stability with respect to oxidation compared to normal titanium alloys, and they allow observation of the diffusion reaction between the titanium-based coatings and the base material (for example aluminum or steel). Coatings of such material can accordingly a Allow reduction of manufacturing costs and improve the protection of allow coated gas turbine components. In other words, pointing Such coatings have high resistance to those typically found in Gas turbines (especially with blades or vanes) occurring Conditions on (high temperature, corrosive environment, strong mechanical Loads, etc.).
  • the atomic percentage of Oxygen can be adjusted in the range of 8 to 12%, and that of aluminum in the range of 1.5 to 3%.
  • compositions can be used very advantageously: Ti 60 Cr 32 Si 4 (SiO 2 ) 4 ; Ti 60 Cr 25 Si 5 (SiO 2 ) 10 ; Ti 65 Cr 25 Si 2.5 (SiO 2 ) 7.5 ; Ti 60 Cr 30 (SiO 2 ) 10 ; Ti 60 Cr 30 Al 2 Si 3 (SiO 2 ) 5 ; Ti 60 Cr 30 Al 3 Si 2 (SiO 2 ) 5 ; Ti 60 Cr 30 Al 2 Si 3 (SiO 2 ) 5 ; Ti 60 Cr 30 Si 5 (SiO 2 ) 5 .
  • the present invention relates to a method for producing a Connection as just described.
  • the individual components respectively Components are advantageously under protective gas or vacuum melted together. This can be done for example in an arc become. But there are also other methods conceivable such as sintering, PVD (Physical Vapor Deposition), plasma spray method etc.
  • the material is tempered.
  • the compound is after their fusion under protective gas particularly preferably in an oven annealed, wherein the material is preferably at a temperature in the range of 1000 to 1300 degrees Celsius is maintained for a period of 80 to 200 hours, and then cooled in the oven.
  • the annealing can be done by different methods, such as gradually, with a scheme of incremental or incremental decreasing temperature or a combination of such schemes used can be.
  • the advantageous properties of the material occur especially when used as a coating. Describes accordingly a further embodiments of the inventive method, the application the compound as a coating on a material, in particular method such as plasma spray or vapor deposition may be used, optionally followed by annealing.
  • the present invention relates to the use of a compound, such as it has been characterized above, respectively produced according to a procedure as above has been described. It is the use of such Material as a material for a component which is exposed to high temperatures, d. H. which is exposed to hot gases in particular, or of hot gases is flowed around. In particular, it is for example a component of a Gas turbine, particularly preferably a blade or vane one Gas turbine.
  • a further preferred use according to the invention is characterized in that that the compound is particularly preferred as the coating directly the hot Gas exposed surface is present. It may optionally below the Coating of said material, a further functional layer in particular for adhesion or for further barrier effect.
  • such a coating has a thickness in the range of 10-400 ⁇ m, particularly preferably in the range of 100 to 300 ⁇ m
  • thermal stress as well as the oxidation of rotor blades or vanes in gas turbines under the influence of the high temperature in combination with the oxidative respectively corrosive conditions reduces the possible lifetime respectively the maximum possible design of the temperature of the combustion process, which on the one hand reduces the efficiency of the combustion Turbine reduced and on the other hand the maintenance costs increased.
  • materials such as yttria-stabilized zirconia (yttrium stabilized ZrO 2 , abbreviated YSZ) are known in connection with the coating of such loaded components. Such coatings are referred to as ceramic thermal barrier layers.
  • the proposed oxygen-containing quasicrystalline alloys based on Titanium have internal ceramic interlayers. Correspondingly protect the materials of the underlying component (metal, eg alloys) oxidation, since the diffusion of oxygen through the layer is prevented. In addition, they lead to a reduction in their low thermal conductivity the surface temperature of the underlying metal of the blades of the Compressor or the gas turbine (especially in the case of internal cooling). In other words, the proposed materials assume the function of a Diffusion barrier (DB) as well as those of a thermal thermal barrier coating (thermal barrier coating, abbreviated TBC).
  • DB Diffusion barrier
  • TBC thermal thermal barrier coating
  • the reduced weight (compared with Blades made of nickel-based superalloys) as well as the possibility of Observation of the diffusion reaction between the coating and the base material allows to ensure a better adhesion to the base material.
  • the observation the diffusion reaction can be carried out, for example, by polishing samples and be brought into contact with a coating according to the invention. Subsequently cuts can be made and TEM or SEM shots of these cuts, in which case the extent of the diffusion is easily recognizable.
  • Embodiments Ti-1, Ti-2 and Ti-3 were after fused together annealed in a resistance oven, keeping at 1225 degrees for 144 hours Celsius (constant temperature) was maintained, and the samples in aluminum crucibles were kept under argon atmosphere. Then they were in the oven cooled.
  • the Ti-4 sample was annealed at 1080 degrees Celsius for 80 Hours in a zirconium crucible.
  • the samples Ti-11 and Ti-12 were also melted down analogously and at more than 1000 degrees during more than 50h tempered.
  • Table 1 also indicates the density, which was determined by measuring the Mass and a measurement of the volume determined according to the Archimedes principle. For the Volume measurement was made as a displacement medium of water at a temperature of 20 Used degrees Celsius. So that the liquid is not immersed in the Pores of the body could penetrate, the body was determined after the determination of Dry weight saturated with this liquid. For fine-capillary substances is suitable especially a potion after cooking. For this purpose, the specimens before the Dried impregnation at 110 ° C to constant weight and then in water of Ambient temperature set. The water is brought to a boil and at least Kept at boiling temperature for 30 minutes. The comparatively low density makes that proposed compounds due to the associated small moving Masses suitable for coatings of moving parts.
  • the Heat capacity measured at 100 degrees Celsius.
  • the Heat capacity was measured continuously by differential thermal analysis (DTA) certainly.
  • DTA differential thermal analysis
  • the measurement was carried out in argon atmosphere. It shows the advantageous for such compounds relatively low Heat capacity.
  • the thermal conductivity ⁇ measured at 100 degrees Celsius.
  • the measurement of density and heat capacity are listed above.
  • the temperature conductivity (TLF) was measured by the laser flash method at certain temperature levels (room temperature, 100, 200, 400, 600, 800, 1000 and 1200 ° C). At each temperature, 5-10 individual measurements were made. From this an average value of the TLF at the also averaged temperature was calculated.
  • a Laserflash system from Netzsch was used (Germany, measurements up to 2000 ° C are possible).
  • the solid-state laser has a wavelength of 1064 nm and a maximum energy output of about 20 joules per shot.
  • the pulse duration can be varied from 0.2 to 1.2 ms.
  • the thermal diffusivity ⁇ indicated in FIG. 6 was measured using the laser flash method in the ACCESS device (E. Pfaff. Report 72-00 (20.09.2000) of Rheinisch-West methodische Technische Hochhoff Aachen).
  • FIGS. 1 to 4 show powder X-ray diffraction patterns of the samples according to FIG. Table 1.
  • the intensity (I) is shown as a function of the diffraction angle (2 theta).
  • the Measurements were taken in a PADX Powder Diffractometer (Scintag, USA), ⁇ of Cu radiation, Ge detector, instead.
  • Fig. 1 shows different powder X-ray diffraction patterns for sample Ti-4.
  • the diffraction pattern for a specimen Ti-4 annealed in a zirconium dioxide crucible is shown in FIG. 1a).
  • FIGS. 1a) -c) with quadrilaterals and arrows the peaks of the structure ⁇ (TiCrSi), ie of the 1/1 approximant of the cubic structure Ti 75-x Cr 25 Si x , where 10 ⁇ x ⁇ 20, are indicated Exclusively with squares, the peaks belonging to the structure Ti 5 Si 3 are given. It can thus be seen how different structures exist side by side.
  • Fig. 1b shows a corresponding sample, which is annealed in a graphite crucible has been.
  • Fig. 1c shows a sample which has not been tempered.
  • FIG. 2 shows corresponding diffraction patterns of the samples Ti-1 (FIG. 2a, not annealed, FIG. VACUMET), Ti-2 ( Figure 2b, not annealed, VACUMET) and Ti-3 ( Figure 2c, not annealed, VACUMET).
  • VACUMET is the melting of Ti alloys in the induction furnace in vacuum with low argon partial pressure (15 Torr) designated in specially prepared graphite crucibles. Again, the individual phases are assigned next to each other.
  • Fig. 3 shows the diffraction patterns of the sample Ti-2, wherein a) a tempered sample b) a non-annealed sample; and c) a non-annealed sample in the VACUMET method.
  • Fig. 4 shows the corresponding diffraction patterns for different ones Method of preparation of sample Ti-3 (a: annealed, b: unannealed, VACUMET). Again, it can be seen how similar these two ways of production Structures arise at least in relation to the diffraction pattern.
  • Fig. 5 the samples were further examined in a Hitachi S-900 "in-lens" field emission scanning electron microscope with an acceleration voltage of 30kV using a standard Everhard-Thornley SE detector and a YAG type BSE detector were used. From the backscattering patterns of Fig. 5a) and b) the different structures and the size of the domains are visible. The light-colored areas denote the alpha phase, the dark areas the phase of Ti 5 Si 3 . It can be seen that larger domains are formed in sample Ti-2 (FIG. 5a) than in sample Ti-4. Both images are images of the surface and refer to measurements of annealed samples.
  • Fig. 5c shows a normal SEM image of the sample Ti-2 after being oxidized at 800 degrees Celsius under air for 500 hours.
  • the uppermost, light layer is a layer of TiO 2
  • the underlying intermediate layer consists of CrO 2 , where u. U. between an adhesion layer is arranged.
  • the lower part of the picture shows the alloy itself.
  • Fig. 5d) shows a backscattering image of the identical sample.
  • Figures 5c) and d) are images of sections perpendicular to the surface of the samples.
  • FIG. 6 shows the thermal diffusivity of the samples Ti-1 (reference numeral 11), Ti-2 (Reference 12), Ti-3 (Reference 13).
  • the thermal diffusivity is one Material property which depicts the speed with which heat passes through a body diffuses. It is a function of the thermal conductivity of the Body as well as its heat capacity. A high thermal conductivity increases the thermal diffusivity of the body, as it allows a rapid migration of heat allowed by the body. On the other hand, a large heat capacity is the reduce thermal diffusivity of the body, as transported heat preferably in Body is stored and not forwarded by this. From Figure 6 is can be seen, in particular the sample Ti-2 just at high temperatures has low thermal diffusivity, which is for the proposed uses is advantageous. Basically, as usual, increasing thermal diffusivity noted for increasing temperature.
  • Fig. 7 shows the thermal conductivity of the samples Ti-1 (reference numeral 11), Ti-2 (Reference 12), Ti-3 (Reference 13), and Ti-4 (Reference 14).
  • the low thermal conductivity is especially low for Sample Ti-2 observe. It must be noted, however, that the thermal conductivity a corresponding layer of YSZ would be even lower, such a layer is but much more brittle and mechanically much less stable than all of the proposed alloys which have typical ductile properties for metals. Basically, there is a not very strongly varying thermal conductivity over the observed and relevant temperature range.
  • FIG. 8 shows the thermal conductivity of a plurality of samples, as summarized in the list of reference numerals. It can be seen that the thermal conductivity of the comparative sample Ti-2 (reference numeral 10) is located in the middle region. Typical samples of YSZ (yttrium stabilized ZnO 2 ) have lower values as well as corresponding AlCo alloys (reference numerals 5-7). As already mentioned in connection with FIG. 7, however, these samples have worse mechanical properties than the proposed compounds.
  • Fig. 9 shows powder diffraction pattern of the sample Ti-2, wherein measurements after different times of oxidation were made. It is about a sample prepared prior to its oxidation in a tempering process had been. The oxidation took place under air at 950 degrees Celsius. It can be recognized how successive oxides are formed on the surface, but how the Condition substantially stabilized after about 50 hours.
  • Fig. 10 shows the corresponding pattern of the same sample, in which case the oxidation at 1100 Degrees Celsius has been performed. One finds a similar behavior as in FIG. 9. Oxidation kinetics were also investigated and shown in FIG. 11. There a slow oxidation is preferred, turns out according to FIG. 11a) at 800 degrees Celsius tempered sample as outstanding. The tempering found during a Time of place. As a comparison material TiAl was given. In particular from FIG 11b), the superiority of samples which have been annealed can be recognized, wherein low temperature annealing usually provides greater stability in terms of oxidation seems to be.

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Description

TECHNISCHES GEBIETTECHNICAL AREA

Die vorliegende Erfindung betrifft quasikristalline oder als Approximant vorliegende Verbindungen, ein Verfahren zu deren Herstellung sowie Verwendungen derartiger Verbindungen insbesondere im Zusammenhang mit der Beschichtung von Hitze ausgesetzten Bauteilen.The present invention relates to quasi-crystalline or approximant Compounds, a process for their preparation and uses of such Compounds in particular in connection with the coating of heat exposed components.

STAND DER TECHNIKSTATE OF THE ART

Die atomare Struktur, die ungefähre Stereochemie und der Mechanismus des Phasenwachstums von Strukturen des Typs Ti-Cr-Si-O sind bekannt und wurden beispielsweise in folgenden wissenschaftlichen Artikeln beschrieben: J. Y. Kim, W. J. Kim, P. C. Gibbons and K. F. Kelton: Neutron Diffraction Determination of Hydrogen Atom Locations in the α(TiCrSiO) 1/1 Crystal Approximant, Phys. Rev. B, 60, (1999); J. L. Libbert, K. F. Kelton, A. L. Goldman and W. B. Yelon: Structural Determination of a 1/1 Rational Approximant to the Icosahedral Phase in Ti-Cr-Si Alloys, Phys. Rev. B, 49, 11675 (1994); J. L. Libbert, J. Y. Kim and K. F. Kelton: Oxygen in Ti(Cr, Mn)-Si Icosahedral Phases and Approximants, Phil. Mag. A, 79, 2209 (1999). U. a. ist auch bekannt, dass der Sauerstoff im Rahmen der Stabilisierung der i-Phase (ikosahedrale, quasikristalline Phase) respektive dessen Approximant eine wesentliche Rolle spielt. Ein Approximant ist eine chemische Struktur mit ähnlicher Zusammensetzung wie jene des zugehörigen Quasikristalls, wobei der Approximant periodische Strukturen mit sehr grossen Einheitszellen und sehr ähnlicher lokaler Ordnung wie jene des zugehörige Quasikristalls aufweist. Der Approximant wird in diesem Zusammenhang als α(TiCrSiO) oder als 1/1 Phase bezeichnet, dies ist die wichtigste Phase in diesen untersuchten Legierungen. Neutronenuntersuchungen zeigen, dass die Sauerstoffatome an denen Oktaederpositionen angeordnet sind, wobei wahrscheinlich eine Bindung zu den Titan-Atomen vorliegt. So wird, basierend auf Energierechnungen, das Vorliegen eines Netzwerks von Oktaedern vermutet.The atomic structure, the approximate stereochemistry and the mechanism of the Phase growth of structures of the type Ti-Cr-Si-O are known and have been for example, in the following scientific articles: J.Y. Kim, W.J. Kim, P.C. Gibbons and K.F. Kelton: Neutron Diffraction Determination of Hydrogen Atom Locations in the α (TiCrSiO) 1/1 Crystal Approximant, Phys. Rev. B, 60, (1999); J.L. Libbert, K.F. Kelton, A.L. Goldman and W.B. Yelon: Structural Determination of a 1/1 Rational Approximant to the icosahedral phase in Ti-Cr-Si Alloys, Phys. Rev. B, 49, 11675 (1994); J.L. Libbert, J.Y. Kim and K.F. Kelton: Oxygen in Ti (Cr, Mn) -Si Icosahedral Phases and Approximants, Phil. Mag. A, 79, 2209 (1999). U. a. is too known that the oxygen in the context of the stabilization of the i-phase (ikosahedrale, quasicrystalline phase) or whose approximant plays an essential role. An approximant is a chemical structure of similar composition to that of the associated quasicrystal, wherein the approximant periodic structures with very large unit cells and very similar local order as those of the corresponding one Quasicristalls has. The approximant is referred to in this context as α (TiCrSiO) or 1/1 phase, this is the most important phase in these examined alloys. Neutron studies show that the oxygen atoms at which octahedral positions are arranged, probably a bond to the titanium atoms present. Thus, based on energy bills, the existence suspected of a network of octahedrons.

Die Titan-basierten quasikristallinen Materialien können entsprechend als metallische Legierungen mit internen keramischen Schichten betrachtet werden.The titanium-based quasicrystalline materials can be classified as metallic Alloys with internal ceramic layers are considered.

Die Auswirkung des Sauerstoffgehalts in Titan auf die Reaktionsdiffusion wurde für die Paarung Ti/Al untersucht, wobei gegossenes Ti/Al mit 5 Molprozent Sauerstoff untersucht wurden, sowie entsprechendes getempertes (annealed) Material (K. Nonaka, H. Fujii and H. Nakajima: Effect of Oxygen in Titanium on Reaction Diffusion Between Ti and Al. Materials Transactions, 42, 1731 (2001)). Das Wachstum einer Zwischenschicht in den Diffusionspaaren des gegossenen Ti(O)/Al wurde dabei unterdrückt im Vergleich mit jenem in Ti/Al Diffusionspaaren. Der entsprechend vorgeschlagene Mechanismus der Unterdrückung beinhaltet die Bildung von Aluminiumoxid an der Grenzfläche zwischen der Zwischenschicht aus TiAl3 und dem Al.The effect of oxygen content in titanium on reaction diffusion was investigated for the Ti / Al pairing, examining cast Ti / Al with 5 mole percent oxygen, and corresponding annealed material (K. Nonaka, H. Fujii and H. Nakajima: Effect of Oxygen in Titanium on Reaction Diffusion Between Ti and Al. Materials Transactions, 42, 1731 (2001)). The growth of an intermediate layer in the diffusion pairs of the cast Ti (O) / Al was suppressed in comparison with that in Ti / Al diffusion pairs. The proposed mechanism of suppression involves the formation of alumina at the interface between the TiAl 3 intermediate layer and the Al.

Die thermische Leitfähigkeit von quasikristallinen Legierungen und deren Approximanten, in welchen nur langwellige Phononen propagieren können, ist niedriger als jene von typischen Metalllegierungen. Dies wurde beispielsweise in folgenden Publikationen beschrieben: P. Archambault, P. Plaindoux, E. Belin-Ferre and J. M. Dubois: Thermal and Electronic Properties of an AlCoFrCr Approximant of the Decagonal Phases, Quasicrystals, MRS, 535, 409 (1999); J. M. Dubois: New Prospects From Potential Applications of Quasicrystal Materials, Mat. Sc. and Engineering, 294-296, 4 (2000). Die thermische Leitfähigkeit von ausschliesslich Aluminium-basierten Quasikristall-Legierungen (oder von deren Approximanten) ist ebenfalls untersucht worden.The thermal conductivity of quasicrystalline alloys and their Approximants in which only long-wave phonons can propagate are lower than those of typical metal alloys. This was for example in the following Publications: P. Archambault, P. Plaindoux, E. Belin-Ferre and J.M. Dubois: Thermal and Electronic Properties of AlCoFrCr Approximant of the Decagonal Phases, Quasicrystals, MRS, 535, 409 (1999); J.M. Dubois: New Prospects From Potential Applications of Quasicrystal Materials, Mat. Sc. and Engineering, 294-296, 4 (2000). The thermal conductivity of exclusively aluminum-based Quasicrystal alloys (or their approximants) are also studied Service.

Ikosahedrale, quasikristalline Legierungen des Typs Ti68-xCr32Six mit 6 ≤ x ≤ 18 werden von Zhang, X. ; kelton, K.F., "Icosahedral phase Formation in Ti68-xCr32Six alloys" Philosophical Magazine Letters, 1990, Vol. 62, No.4, 265-271, 1990, offenbart. Icosahedral, quasi-crystalline alloys of the Ti 68-x Cr 32 Si x type with 6 ≤ x ≤ 18 are disclosed by Zhang, X.; Kelton, KF, "Icosahedral phase formation in Ti 68-x Cr 32 Si x alloys" Philosophical Magazine Letters, 1990, Vol. 62, No.4, 265-271, 1990.

DARSTELLUNG DER ERFINDUNGPRESENTATION OF THE INVENTION

Der Erfindung liegt demnach die Aufgabe zugrunde, eine neue quasikristalline oder als Approximant vorliegende Verbindung zur Verfügung zu stellen. Die Verbindung soll dabei vorteilhafte Eigenschaften aufweisen, wie sie insbesondere im Zusammenhang mit der Verwendung als Beschichtung von von heissen Gasen umströmten Bauteilen, welche beispielsweise in Gasturbinen eingesetzt werden, erforderlich sind. So soll die Verbindung respektive die Klasse von Verbindungen eine entsprechende Stärke respektive Festigkeit und Dichte aufweisen, soll eine niedrige thermische Leitfähigkeit aufweisen, möglichst ausserdem eine Diffusionsbarriere für Sauerstoff darstellen, eine hohe Stabilität in Bezug auf Oxidation aufweisen, sowie möglicherweise die Beobachtung von Diffusionsreaktionen zwischen der Verbindung und dem Material, auf welchem die Verbindung aufgetragen ist, ermöglichen.The invention is therefore based on the object, a new quasicrystalline or as Provide approximant present connection. The connection should have advantageous properties, as in particular in connection with the use as a coating of components flowed around by hot gases, which are used for example in gas turbines, are required. So shall the Connection respectively the class of connections a corresponding strength respectively strength and density, is said to have a low thermal conductivity as far as possible also constitute a diffusion barrier for oxygen, a have high stability with respect to oxidation, and possibly the Observation of diffusion reactions between the compound and the material, on which the compound is applied allow.

Die Lösung dieser Aufgabe wird dadurch erreicht, dass die Verbindung ikosahedrale, quasikristalline oder entsprechende Approximant-Struktur aufweist, und eine nominale Zusammensetzung der folgenden Art hat: TivCrwAlxSiyOz wobei v = 60-65; w = 25-30; x = 0 - 6; y = 8 - 15; z = 8 - 20. Damit sich tatsächlich eine entsprechende quasikristalline respektive Approximant-Struktur ausbildet, muss ausserdem beachtet werden, dass der Atomprozentgehalt von Sauerstoff im Bereich von 8-20 % liegt, vorzugsweise 8 bis 15 % liegt. Unterhalb dieses Gehalts bildet sich die gewünschte Struktur nicht aus, und oberhalb bildet sich eine Oxidphase. Ausserdem wird vorteilhafterweise der Atomprozentgehalt von Aluminium auf einen Bereich von 2 bis 5 % eingestellt. Selbstverständlich sind auch entsprechende Kombinationen von derartigen Materialien denkbar.The solution to this problem is achieved in that the compound has icosahedral, quasicrystalline or corresponding approximant structure, and has a nominal composition of the following type: Ti v Cr w Al x Si y O z where v = 60-65; w = 25-30; x = 0 - 6; y = 8 - 15; z = 8-20. In order for a corresponding quasicrystalline or approximant structure to be formed, it must also be noted that the atomic percentage of oxygen is in the range of 8-20%, preferably 8 to 15%. Below this content, the desired structure is not formed, and above forms an oxide phase. In addition, the atomic percentage of aluminum is advantageously adjusted to a range of 2 to 5%. Of course, corresponding combinations of such materials are conceivable.

Der Kern der Erfindung besteht somit darin, die für Titanlegierungen übliche Festigkeit und Dichte auszunutzen, sowie die niedrige thermische Leitfähigkeit von quasikristallinen Legierungen. Ausserdem ermöglichen die keramischen Zwischenschichten die Verhinderung von Diffusion durch die Schicht (Diffusionsbarrieren). Die vorgeschlagenen Verbindungen verfügen ausserdem über eine verbesserte Stabilität in Bezug auf Oxidation im Vergleich zu normalen Titan-Legierungen, und sie ermöglichen eine Beobachtung der Diffusionsreaktion zwischen den Titan-basierten Beschichtungen und dem Basismaterial (beispielsweise Aluminium oder Stahl). Beschichtungen aus derartigem Material können entsprechend eine Reduktion der Herstellungskosten erlauben und eine Verbesserung des Schutzes von beschichteten Gasturbinenkomponenten ermöglichen. Mit anderen Worten weisen derartige Beschichtungen eine hohe Widerstandsfähigkeit für die typischerweise in Gasturbinen (insbesondere bei Laufschaufeln oder Leitschaufeln) auftretenden Bedingungen auf (hohe Temperatur, korrosive Umgebung, starke mechanische Belastungen, etc.).The core of the invention thus consists of the usual strength for titanium alloys and density, as well as the low thermal conductivity of quasicrystalline alloys. In addition, the ceramic allow Interlayers prevent diffusion through the layer (Diffusion barrier). The proposed compounds also have improved stability with respect to oxidation compared to normal titanium alloys, and they allow observation of the diffusion reaction between the titanium-based coatings and the base material (for example aluminum or steel). Coatings of such material can accordingly a Allow reduction of manufacturing costs and improve the protection of allow coated gas turbine components. In other words, pointing Such coatings have high resistance to those typically found in Gas turbines (especially with blades or vanes) occurring Conditions on (high temperature, corrosive environment, strong mechanical Loads, etc.).

Gemäss einer ersten bevorzugten Ausführungsform werden die eingangs genannten Parameter wie folgt eingestellt: v = 60; w = 30; x = 0 - 3; y = 8 - 15 (insbesondere bevorzugt 8 - 10); z = 8 - 20 (insbesondere bevorzugt 8 - 10). Damit die Bildung der gewünschten Struktur tatsächlich stattfindet, sollte der Atomprozentgehalt von Sauerstoff im Bereich von 8 bis 12% eingestellt werden, und derjenige von Aluminium im Bereich von 1.5 bis 3%.According to a first preferred embodiment, the aforementioned Parameter set as follows: v = 60; w = 30; x = 0-3; y = 8 - 15 (in particular preferably 8-10); z = 8-20 (more preferably 8-10). Thus the formation of the desired structure actually takes place, the atomic percentage of Oxygen can be adjusted in the range of 8 to 12%, and that of aluminum in the range of 1.5 to 3%.

Weiterhin verbesserte Eigenschaften lassen sich erreichen, wenn die Parameter wie folgt eingestellt werden: v = 60; w = 30; x = 0 - 2; y = 8 - 10; wobei der Atomprozentgehalt von Sauerstoff im Bereich von 10% liegt, und derjenige von Aluminium im Bereich von 1.5 bis 2.5%. Konkret lassen sich insbesondere folgende Zusammensetzungen sehr vorteilhaft einsetzen: Ti60Cr32Si4(SiO2)4; Ti60Cr25Si5(SiO2)10; Ti65Cr25Si2.5(SiO2)7.5 ; Ti60Cr30(SiO2)10 ; Ti60Cr30Al2Si3(SiO2)5; Ti60Cr30Al3Si2(SiO2)5; Ti60Cr30Al2Si3(SiO2)5; Ti60Cr30Si5(SiO2)5.Further improved properties can be achieved if the parameters are set as follows: v = 60; w = 30; x = 0-2; y = 8-10; wherein the atomic percentage of oxygen is in the range of 10%, and that of aluminum in the range of 1.5 to 2.5%. Specifically, in particular the following compositions can be used very advantageously: Ti 60 Cr 32 Si 4 (SiO 2 ) 4 ; Ti 60 Cr 25 Si 5 (SiO 2 ) 10 ; Ti 65 Cr 25 Si 2.5 (SiO 2 ) 7.5 ; Ti 60 Cr 30 (SiO 2 ) 10 ; Ti 60 Cr 30 Al 2 Si 3 (SiO 2 ) 5 ; Ti 60 Cr 30 Al 3 Si 2 (SiO 2 ) 5 ; Ti 60 Cr 30 Al 2 Si 3 (SiO 2 ) 5 ; Ti 60 Cr 30 Si 5 (SiO 2 ) 5 .

Weitere bevorzugte Ausführungsformen der erfindungsgemässen Verbindung sind in den abhängigen Ansprüchen beschrieben.Further preferred embodiments of the inventive compound are in described the dependent claims.

Weiterhin betrifft die vorliegende Erfindung ein Verfahren zur Herstellung einer Verbindung, wie sie gerade beschrieben wurde. Die einzelnen Bestandteile respektive Komponenten werden dabei vorteilhafterweise unter Schutzgas bzw. Vakuum zusammengeschmolzen. Dies kann beispielsweise in einem Lichtbogen durchgeführt werden. Es sind aber auch andere Verfahren denkbar wie beispielsweise Sintern, PVD (Physical Vapour Deposition), Plasmaspray-Verfahren etc.Furthermore, the present invention relates to a method for producing a Connection as just described. The individual components respectively Components are advantageously under protective gas or vacuum melted together. This can be done for example in an arc become. But there are also other methods conceivable such as sintering, PVD (Physical Vapor Deposition), plasma spray method etc.

Gemäss einer besonders bevorzugten Ausbildung des erfindungsgemässen Verfahrens wird ausserdem das Material getempert. Vorzugsweise wird dabei die Verbindung nach deren Zusammenschmelzen unter Schutzgas insbesondere bevorzugt in einem Ofen getempert, wobei das Material bevorzugt bei einer Temperatur im Bereich von 1000 bis 1300 Grad Celsius während einer Zeit von 80 bis 200 Stunden gehalten wird, und anschliessend im Ofen abgekühlt wird.According to a particularly preferred embodiment of the inventive method In addition, the material is tempered. Preferably, the compound is after their fusion under protective gas particularly preferably in an oven annealed, wherein the material is preferably at a temperature in the range of 1000 to 1300 degrees Celsius is maintained for a period of 80 to 200 hours, and then cooled in the oven.

Das Tempern kann dabei nach unterschiedlichen Verfahren erfolgen, so beispielsweise stufenweise, wobei ein Schema mit stufenweise zunehmender oder mit stufenweise abnehmender Temperatur oder eine Kombination derartiger Schemata verwendet werden kann.The annealing can be done by different methods, such as gradually, with a scheme of incremental or incremental decreasing temperature or a combination of such schemes used can be.

Wie bereits eingangs erwähnt, treten die vorteilhaften Eigenschaften des Materials insbesondere bei dessen Verwendung als Beschichtung hervor. Entsprechend beschreibt eine weitere Ausführungsformen des erfindungsgemässen Verfahrens das Aufbringen der Verbindung als Beschichtung auf einen Werkstoff, wobei insbesondere Verfahren wie Plasmaspray-Verfahren oder Dampfabscheidung Anwendung finden können, gegebenenfalls gefolgt von einem Tempern.As already mentioned, the advantageous properties of the material occur especially when used as a coating. Describes accordingly a further embodiments of the inventive method, the application the compound as a coating on a material, in particular method such as plasma spray or vapor deposition may be used, optionally followed by annealing.

Weitere bevorzugte Ausführungsformen des erfindungsgemässen Verfahrens zur Herstellung der Verbindung respektive des Materials sind in den abhängigen Ansprüchen skizziert.Further preferred embodiments of the inventive method for Production of the compound respectively of the material are in the dependent ones Claims outlined.

Ausserdem betrifft die vorliegende Erfindung die Verwendung einer Verbindung, wie sie oben charakterisiert wurde, respektive hergestellt nach einem Verfahren, wie es oben beschrieben wurde. Es handelt sich dabei um die Verwendung eines derartigen Materials als Werkstoff für ein Bauteil, welches hohen Temperaturen ausgesetzt ist, d. h. welches insbesondere heissen Gasen ausgesetzt ist, respektive von heissen Gasen umströmt wird. Insbesondere handelt es sich zum Beispiel um ein Bauteil einer Gasturbine, insbesondere bevorzugt um eine Laufschaufel oder Leitschaufel einer Gasturbine.Moreover, the present invention relates to the use of a compound, such as it has been characterized above, respectively produced according to a procedure as above has been described. It is the use of such Material as a material for a component which is exposed to high temperatures, d. H. which is exposed to hot gases in particular, or of hot gases is flowed around. In particular, it is for example a component of a Gas turbine, particularly preferably a blade or vane one Gas turbine.

Eine weitere bevorzugte erfindungsgemässe Verwendung ist dadurch gekennzeichnet, dass die Verbindung als Beschichtung insbesondere bevorzugt der direkt den heissen Gasen ausgesetzten Oberfläche vorliegt. Dabei kann gegebenenfalls unterhalb der Beschichtung aus dem besagten Material eine weitere Funktionsschicht insbesondere zur Haftvermittlung oder zur weiteren Barrierewirkung vorliegen.A further preferred use according to the invention is characterized in that that the compound is particularly preferred as the coating directly the hot Gas exposed surface is present. It may optionally below the Coating of said material, a further functional layer in particular for adhesion or for further barrier effect.

Typischerweise weist eine derartige Beschichtung eine Dicke von im Bereich von 10-400 µm, insbesondere bevorzugt im Bereich von 100 bis 300 µm aufTypically, such a coating has a thickness in the range of 10-400 μm, particularly preferably in the range of 100 to 300 μm

Weitere bevorzugte erfindungsgemässe Verwendungen sind in den abhängigen Ansprüchen beschrieben.Further preferred uses according to the invention are in the dependent Claims described.

KURZE ERLÄUTERUNG DER FIGURENBRIEF EXPLANATION OF THE FIGURES

Die Erfindung soll nachfolgend anhand von Ausführungsbeispielen im Zusammenhang mit den Zeichnungen näher erläutert werden. Es zeigen:

Fig.
1 Röntgendiffraktionsdaten des Beispiels Ti-4, wobei a) das Spektrum für eine Probe mit Tempern in einem Zirkondioxid-Tiegel darstellt, b) das Spektrum für eine Probe mit Tempern in einem Graphit-Tiegel, und c) das Spektrum für eine Probe ohne Tempern darstellt;
Fig. 2
Röntgendiffraktionsdaten der Beispiele Ti-1 (a), Ti-2 (b) und Ti-3 (c) ohne Tempern (Vacumet-Verfahren);
Fig. 3
Röntgendiffraktionsdaten des Beispiels Ti-2, wobei a) das Spektrum für eine Probe mit Tempern darstellt, b) das Spektrum für eine Probe ohne Tempern darstellt, und c) das Spektrum für eine Probe ohne Tempern darstellt (Vacumet Verfahren);
Fig. 4
Röntgendiffraktionsdaten des Beispiels Ti-3, wobei a) das Spektrum für eine Probe mit Tempern darstellt, und b) das Spektrum für eine Probe ohne Tempern darstellt (Vacumet Verfahren);
Fig. 5
Rasterelektronenmikroskopische Aufnahmen (SEM), a) Backscattering-Muster der ausgeglühten Probe Ti-2; b) Backscattering-Muster der ausgeglühten Probe Ti-4; c) und d) normales Muster und Backscattering-Muster der Probe Ti-2, nach Oxidation bei 800 Grad Celsius unter Luft während 500 Stunden;
Fig. 6
thermische Diffusivität der Proben Ti-1, Ti-2 und Ti-3;
Fig. 7
Vergleiche der thermischen Leitfähigkeit der Proben Ti-1, Ti-2, Ti-3 und Ti-4;
Fig. 8
Vergleiche der thermischen Leitfähigkeit von Ti-2 mit verschiedenen Proben nach dem Stand der Technik;
Fig. 9
Röntgendiffraktionsdaten des Beispiels Ti-2 nach unterschiedlichen Zeiten der Oxidation bei 950 Grad Celsius unter Luft ;
Fig.
10 Röntgendiffraktionsdaten des Beispiels Ti-2 nach unterschiedlichen Zeiten der Oxidation bei 1100 Grad Celsius unter Luft ; und
Fig.
11 Oxidationskinetik, a) Vergleich der Oxidation von Ti-2 und TiAl ;b) Vergleich der Oxidation von Ti-2 mit und ohne Tempern.
The invention will be explained in more detail with reference to embodiments in conjunction with the drawings. Show it:
FIG.
1 X-ray diffraction data of Example Ti-4, where a) represents the spectrum for a sample with annealing in a zirconia crucible, b) the spectrum for a sample with annealing in a graphite crucible, and c) the spectrum for a sample without annealing represents;
Fig. 2
X-ray diffraction data of examples Ti-1 (a), Ti-2 (b) and Ti-3 (c) without annealing (Vacumet method);
Fig. 3
X-ray diffraction data of Example Ti-2, where a) represents the spectrum for a sample with anneals, b) represents the spectrum for a sample without annealing, and c) represents the spectrum for a sample without annealing (Vacumet method);
Fig. 4
X-ray diffraction data of Example Ti-3, where a) represents the spectrum for a sample with anneals, and b) represents the spectrum for a sample without annealing (Vacumet method);
Fig. 5
Scanning electron micrographs (SEM), a) backscattering pattern of the annealed Ti-2 sample; b) Backscattering pattern of annealed sample Ti-4; c) and d) normal pattern and backscattering pattern of sample Ti-2, after oxidation at 800 degrees Celsius under air for 500 hours;
Fig. 6
thermal diffusivity of the samples Ti-1, Ti-2 and Ti-3;
Fig. 7
Comparing the thermal conductivity of the samples Ti-1, Ti-2, Ti-3 and Ti-4;
Fig. 8
Comparing the thermal conductivity of Ti-2 with various prior art samples;
Fig. 9
X-ray diffraction data of Example Ti-2 after different times of oxidation at 950 degrees Celsius in air;
FIG.
10 X-ray diffraction data of Example Ti-2 after different times of oxidation at 1100 degrees Celsius under air; and
FIG.
11 Oxidation kinetics, a) Comparison of the oxidation of Ti-2 and TiAl, b) Comparison of the oxidation of Ti-2 with and without annealing.

WEGE ZUR AUSFÜHRUNG DER ERFINDUNGWAYS FOR CARRYING OUT THE INVENTION

Die thermische Belastung sowie die Oxidation von Laufschaufeln oder Leitschaufeln in Gasturbinen unter dem Einfluss der hohen Temperatur in Kombination mit den oxidativen respektive korrosiven Bedingungen reduziert die mögliche Lebensdauer respektive die mögliche maximale Auslegung der Temperatur des Prozesses der Verbrennung, was auf der einen Seite die Effizienz der Turbine reduziert und auf der anderen Seite die Unterhaltskosten erhöht. Nach dem Stand der Technik sind im Zusammenhang mit der Beschichtung von derartig belasteten Komponenten Materialien wie beispielsweise mit Yttriumoxid stabilisiertes Zirkondioxid (Yttrium stabilized ZrO2, abgekürzt YSZ) bekannt. Derartige Beschichtungen werden als keramische thermische Barriereschichten bezeichnet. Trotz ihrer ungenügenden mechanischen Stabilität respektive Integrität, trotz des hohen spezifischen Gewichts und obwohl derartige Schichten für Sauerstoff im wesentlichen durchlässig sind, sind diese Materialien nach wie vor einzigartig für den Schutz der Oberflächen des Basismetalls insbesondere der Laufschaufeln respektive Leitschaufeln der ersten Stufe von Niederdruck-Gasturbinen. Dort treten bekanntermassen die besonders hohen Temperaturen im Bereich von 900 bis 950 Grad Celsius auf. Die ungekühlten dritten und vierten Stufen können unter Zuhilfenahme von Titan-Legierungen hergestellt werden, welche ein gutes Verhältnis von Festigkeit zu Dichte aufweisen aber einen Schutz vor Oxidation respektive Korrosion erforderlich machen.The thermal stress as well as the oxidation of rotor blades or vanes in gas turbines under the influence of the high temperature in combination with the oxidative respectively corrosive conditions reduces the possible lifetime respectively the maximum possible design of the temperature of the combustion process, which on the one hand reduces the efficiency of the combustion Turbine reduced and on the other hand the maintenance costs increased. According to the prior art, materials such as yttria-stabilized zirconia (yttrium stabilized ZrO 2 , abbreviated YSZ) are known in connection with the coating of such loaded components. Such coatings are referred to as ceramic thermal barrier layers. Despite their inadequate mechanical stability and integrity, despite the high specific gravity, and although such layers are substantially permeable to oxygen, these materials are still unique in protecting the surfaces of the base metal, particularly the first stage buckets and vanes of low pressure gas turbines , There are known to be the particularly high temperatures in the range of 900 to 950 degrees Celsius. The uncooled third and fourth stages can be made with the aid of titanium alloys which have a good strength to density ratio but require protection against oxidation or corrosion.

Die vorgeschlagenen, sauerstoffhaltigen quasikristallinen Legierungen auf Basis von Titan verfügen über interne keramische Zwischenschichten. Entsprechend schützen Sie die Materialien des darunter liegenden Bauteils (Metall, beispielsweise Legierungen) vor Oxidation, da die Diffusion von Sauerstoff durch die Schicht verhindert wird. Ausserdem führen sie durch die niedrige thermische Leitfähigkeit zu einer Reduktion der Oberflächentemperatur des darunter liegenden Metalls der Schaufeln des Kompressors respektive der Gasturbine (insbesondere im Fall einer internen Kühlung). Die vorgeschlagenen Materialien übernehmen mit anderen Worten die Funktion einer Diffusionsbarriere (DB) sowie auch jene einer thermischen Wärmedämmschicht (thermal barrier coating, abgekürzt TBC). Das reduzierte Gewicht (verglichen mit Schaufeln aus Nickel-basierten Superlegierungen) sowie die Möglichkeit der Beobachtung der Diffusionsreaktion zwischen der Beschichtung und dem Basismaterial erlaubt es, eine bessere Adhäsion zum Basismaterial sicherzustellen. Die Beobachtung der Diffusionsreaktion kann beispielsweise erfolgen, indem Proben poliert werden und mit einer erfindungsgemässen Beschichtung in Kontakt gebracht werden. Anschliessend können Schnitte gemacht werden und TEM oder SEM-Aufnahmen dieser Schnitte, wobei dann das Ausmass der Diffusion leicht erkennbar ist.The proposed oxygen-containing quasicrystalline alloys based on Titanium have internal ceramic interlayers. Correspondingly protect the materials of the underlying component (metal, eg alloys) oxidation, since the diffusion of oxygen through the layer is prevented. In addition, they lead to a reduction in their low thermal conductivity the surface temperature of the underlying metal of the blades of the Compressor or the gas turbine (especially in the case of internal cooling). In other words, the proposed materials assume the function of a Diffusion barrier (DB) as well as those of a thermal thermal barrier coating (thermal barrier coating, abbreviated TBC). The reduced weight (compared with Blades made of nickel-based superalloys) as well as the possibility of Observation of the diffusion reaction between the coating and the base material allows to ensure a better adhesion to the base material. The observation the diffusion reaction can be carried out, for example, by polishing samples and be brought into contact with a coating according to the invention. Subsequently cuts can be made and TEM or SEM shots of these cuts, in which case the extent of the diffusion is easily recognizable.

Zur Überprüfung dieser Eigenschaften wurden verschiedene Legierungen hergestellt, wobei jeweils 100 Gramm in einem Lichtbogen zusammengeschmolzen wurden. Dieses Zusammenschmelzen fand unter Schutzgasatmosphäre statt, wobei Argon als Schutzgas verwendet wurde. Die einzelnen Proben wurden mit Ti-1 bis Ti-4 respektive Ti-11 und Ti-12 bezeichnet, und sind in ihrer nominalen Zusammensetzung in Tabelle 1 zusammengefasst: No. Nominale Zusammensetzung Peritek. Temper. (°C) Liquidus Temper. (°C) EDX (at%) ρ (gcm-3) cp (Jg-1K-1) (100°C) λ (Wm-1K-1) (100°C) Ti Cr Si Al Ti-1 Ti60CT32Si4(SiO2)4
(i-Phase ist Hauptphase) 1270
1580 62.8
36.7 28.8
57.0 8.4
6.3 - 5234 0.557 7.35 Ti-2 Ti60Cr25Si5(SiO2)10
(1/1 Approximant als Hauptphase) 1525
1665 57.8
32.6
55.1 33.9
53.7
9.9 11.7
13.7
35.0 - 5.099 0.591 8.30 Ti-3 Ti65Cr25Si2.5(SiO2)7.5
(1/1 Approximant als Hauptphase) 1310
1575 - - - - 4.960 0.531 7.03 Ti-4 Ti60Cr30(SiO2)10
(1/1 Approximant als Hauptphase) 1275
1535 57.8
34.6
99.0 29.7
57.1
1.0 12.5
8.3
- - - - - Ti-11 Ti60Cr30Al2Si3(SiO2)5 1305
1585 62.0
37.1 28.6
57.8 7.6
4.8 1.7 0.6 5210 0.531 6.21 Ti-12 Ti60Cr30Al3Si2(SiO2)5 1315
1565 63.0
37.2 29.7
57.8 5.3
4.2 1.9 0.7 5.030 0.763 10.40 To verify these properties, various alloys were made, each melting 100 grams in an arc. This fusion took place under a protective gas atmosphere using argon as a protective gas. The individual samples were designated Ti-1 to Ti-4 or Ti-11 and Ti-12, respectively, and are summarized in their nominal composition in Table 1: No. Nominal composition Peritek. Temper. (° C) Liquidus temper. (° C) EDX (at%) ρ (gcm -3 ) c p (Jg -1 K -1 ) (100 ° C) λ (Wm -1 K -1 ) (100 ° C) Ti Cr Si al Ti-1 Ti 60 CT 32 Si 4 (SiO 2 ) 4
(i-phase is main phase) 1270
1580 62.8
36.7 28.8
57.0 8.4
6.3 - 5234 0557 7:35 Ti-2 Ti 60 Cr 25 Si 5 (SiO 2 ) 10
(1/1 approximant as main phase) 1525
1665 57.8
32.6
55.1 33.9
53.7
9.9 11.7
13.7
35.0 - 5099 0591 8.30 Ti-3 Ti 65 Cr 25 Si 2.5 (SiO 2 ) 7.5
(1/1 approximant as main phase) 1310
1575 - - - - 4960 0531 7:03 Ti-4 Ti 60 Cr 30 (SiO 2 ) 10
(1/1 approximant as main phase) 1275
1535 57.8
34.6
99.0 29.7
57.1
1.0 12.5
8.3
- - - - - Ti-11 Ti 60 Cr 30 Al 2 Si 3 (SiO 2 ) 5 1305
1585 62.0
37.1 28.6
57.8 7.6
4.8 1.7 0.6 5210 0531 6.21 Ti-12 Ti 60 Cr 30 Al 3 Si 2 (SiO 2 ) 5 1315
1565 63.0
37.2 29.7
57.8 5.3
4.2 1.9 0.7 5030 0763 10:40

Die Ausführungsbeispiele Ti-1, Ti-2 und Ti-3 wurden nach dem Zusammenschmelzen in einem Widerstandsofen getempert, wobei während 144 Stunden bei 1225 Grad Celsius (konstante Temperatur) gehalten wurde, und wobei die Proben in Aluminium-Tiegeln unter Argon-Atmosphäre gehalten wurden. Anschliessend wurden sie im Ofen ausgekühlt. Die Probe Ti-4 wurde einer Temperung bei 1080 Grad Celsius während 80 Stunden in einem Zirkon-Tiegel unterzogen. Die Proben Ti-11 und Ti-12 wurden ebenfalls analog zusammengeschmolzen und bei mehr als 1000 Grad während mehr als 50h getempert.Embodiments Ti-1, Ti-2 and Ti-3 were after fused together annealed in a resistance oven, keeping at 1225 degrees for 144 hours Celsius (constant temperature) was maintained, and the samples in aluminum crucibles were kept under argon atmosphere. Then they were in the oven cooled. The Ti-4 sample was annealed at 1080 degrees Celsius for 80 Hours in a zirconium crucible. The samples Ti-11 and Ti-12 were also melted down analogously and at more than 1000 degrees during more than 50h tempered.

Einige Eigenschaften der untersuchten 6 Proben sind in Tabelle 1 dargestellt. Die peritektischen Temperaturen liegen durchwegs oberhalb von 1200 Grad Celsius, die Liquidustemperaturen liegen oberhalb von 1500 Grad Celsius. Dadurch, dass die Schmelzpunkte der Legierungen wesentlich oberhalb von 1200 Grad Celsius liegen sind insofern diese Verbindungen für die Verwendung als Beschichtung bei Gasturbinen geeignet.Some properties of the examined 6 samples are shown in Table 1. The peritectic temperatures are consistently above 1200 degrees Celsius, the Liquidus temperatures are above 1500 degrees Celsius. Because of that Melting points of the alloys are substantially above 1200 degrees Celsius insofar as these compounds are for use as a coating in gas turbines suitable.

Die differenzialthermische Analyse wurde in einem Gerät mit der Möglichkeit von Messungen bei Temperaturen bis 3000 Grad Celsius durchgeführt (HDTA, Design des Institute of Material Science Problems, Ukraine; siehe Beschreibung in: Yu. A. Kocherjinsky, E. A. Shishkin and V. I. Vasilenko. "Phase Diagrams of Metallic Systems", "Nauka", Moscow, 1971, p. 245). Die entsprechenden Daten sind mit Kommentaren in Tabelle 2 zusammengefasst: Probe Heizen Kühlen Temperatur, °C Kommentar Temperatur, °C Kommentar Ti-1 1270 Peritektische Reaktion 1380 peritektische Reaktion 1315 Umkehrpunkt (return point) 1330 Phasenübergang 1350 Umkehrpunkt (return point) 1580 Liquidus 1460 Liquidus 1640 Maximale Heiztemperatur Ti-2 1525 Peritektische Reaktion peritektische Reaktion 1575 Solidus 1635 solidus? 1665 Liquidus Liquidus 1880 Maximale Heiztemperatur Ti-3 1310 Peritektische Reaktion 1380 peritektische Reaktion 1350 Umkehrpunkt (return point) 1540 Phasenübergang 1470 Phasenübergang 1575 Liquidus 1500 Liquidus 1660 Maximale Heiztemperatur Ti-4 1275 Peritektische Reaktion 1390 peritektische Reaktion 1310 Umkehrpunkt (return point) 1322 Phasenübergang 1380 Umkehrpunkt (return point) 1400 Phasenübergang 1540 Phasenübergang 1500 Phasenübergang 1580 Phasenübergang 1600 Liquidus 1535 Liquidus 1700 Maximale Heiztemperatur T1-11 1305 Peritektische Reaktion 1355 peritektische Reaktion 1360 Umkehrpunkt (return point) 1385 Phasenübergang 1540 Phasenübergang 1515 Phasenübergang 1570 Umkehrpunkt (return point) 1585 Liquidus 1540 Liquidus 1660 Maximale Heiztemperatur Ti-12 1315 Solidus 1350 peritektische Reaktion 1350 Umkehrpunkt (return point) 1355 Phasenübergang 1380 Phasenübergang 1360 Umkehrpunkt (return point) 1565 Liquidus 1475 Liquidus 1630 maximale Heiztemperatur The differential thermal analysis was carried out in a device with the possibility of measurements at temperatures up to 3000 degrees Celsius (HDTA, Design of the Institute of Material Science Problems, Ukraine, see description in: Yu A. Kocherinsky, EA Shishkin and VI Vasilenko Diagrams of Metallic Systems "," Nauka ", Moscow, 1971, p.245). The corresponding data are summarized with comments in Table 2: sample Heat Cool Temperature, ° C comment Temperature, ° C comment Ti-1 1270 Peritectic reaction 1380 peritectic reaction 1315 Reversal point 1330 Phase transition 1350 Reversal point 1580 liquidus 1460 liquidus 1640 Maximum heating temperature Ti-2 1525 Peritectic reaction peritectic reaction 1575 Solidus 1635 solidus? 1665 liquidus liquidus 1880 Maximum heating temperature Ti-3 1310 Peritectic reaction 1380 peritectic reaction 1350 Reversal point 1540 Phase transition 1470 Phase transition 1575 liquidus 1500 liquidus 1660 Maximum heating temperature Ti-4 1275 Peritectic reaction 1390 peritectic reaction 1310 Reversal point 1322 Phase transition 1380 Reversal point 1400 Phase transition 1540 Phase transition 1500 Phase transition 1580 Phase transition 1600 liquidus 1535 liquidus 1700 Maximum heating temperature T1-11 1305 Peritectic reaction 1355 peritectic reaction 1360 Reversal point 1385 Phase transition 1540 Phase transition 1515 Phase transition 1570 Reversal point 1585 liquidus 1540 liquidus 1660 Maximum heating temperature Ti-12 1315 Solidus 1350 peritectic reaction 1350 Reversal point 1355 Phase transition 1380 Phase transition 1360 Reversal point 1565 liquidus 1475 liquidus 1630 maximum heating temperature

Ausserdem ist in Tabelle 1 die mit EDX (Dispersive X-Ray Spectroscopy) ermittelte Zusammensetzung der Phasen in Atom% angegeben. Die jeweils erste Zeile bezeichnet die Hauptphase der entsprechenden Legierungen. Diese Messung der Phasenkonzentration erfolgte in einem Gerät des Typs JEOL JSM-6400 scanninc electron microscope, welches mit einem EDX-Detektor unter Verwendung der Software VOYAGER ausgerüstet war.In addition, in Table 1, those determined by EDX (Dispersive X-Ray Spectroscopy) Composition of phases in atom% indicated. The respective first line denotes the main phase of the corresponding alloys. This measurement of Phase concentration was carried out in a JEOL JSM-6400 scanninc apparatus electron microscope working with an EDX detector using software VOYAGER was equipped.

In Tabelle 1 ist ausserdem die Dichte angegebenen, diese wurde über eine Messung der Masse und eine Messung des Volumens nach dem Archimedesprinzip bestimmt. Für die Volumenmessung wurde als Verdrängungsmedium Wasser bei einer Temperatur von 20 Grad Celsius benutzt. Damit die Flüssigkeit während der Tauchwägung nicht in die Poren der Körpers dringen konnte, wurde der Körper nach der Bestimmung des Trockengewichts mit dieser Flüssigkeit gesättigt. Für feinkapillare Stoffe eignet sich besonders ein Tränken nach Kochen. Hierzu werden die Probenkörper vor der Tränkung bei 110 °C bis zur Gewichtskonstanz getrocknet und dann in Wasser von Umgebungstemperatur gelegt. Das Wasser wird zum Kochen gebracht und mindestens 30 Min. auf Siedetemperatur gehalten. Die vergleichsweise niedrige Dichte macht die vorgeschlagenen Verbindungen infolge der damit verbundenen kleinen bewegten Massen geeignet für Beschichtungen von bewegten Teilen.Table 1 also indicates the density, which was determined by measuring the Mass and a measurement of the volume determined according to the Archimedes principle. For the Volume measurement was made as a displacement medium of water at a temperature of 20 Used degrees Celsius. So that the liquid is not immersed in the Pores of the body could penetrate, the body was determined after the determination of Dry weight saturated with this liquid. For fine-capillary substances is suitable especially a potion after cooking. For this purpose, the specimens before the Dried impregnation at 110 ° C to constant weight and then in water of Ambient temperature set. The water is brought to a boil and at least Kept at boiling temperature for 30 minutes. The comparatively low density makes that proposed compounds due to the associated small moving Masses suitable for coatings of moving parts.

Ebenfalls angegeben ist die Wärmekapazität gemessen bei 100 Grad Celsius. Die Wärmekapazität wurde kontinuierlich mit Hilfe der Differenzthermoanalyse (DTA) bestimmt. Dazu wurde ein Gerät des Typs DSC 404/So der Fa. Netzsch (Deutschland) verwendet. Es handelte sich dabei um eine hochvakuumtaugliche Sonderversion der DSC 404, welche die Bestimmung von Wärmekapazitäten und Umwandlungswärmen mit der Wärmeflussmethode von 0 °C bis zu 1400 °C erlaubt. Dabei sind Aufheizraten von bis zu 20 K/min möglich. Die Messung wurde in Argon-Atmosphäre durchgeführt. Es zeigt sich die für derartige Verbindungen vorteilhafte vergleichsweise niedrige Wärmekapazität.Also stated is the heat capacity measured at 100 degrees Celsius. The Heat capacity was measured continuously by differential thermal analysis (DTA) certainly. For this purpose, a device of the type DSC 404 / So of the company Netzsch (Germany) used. It was a high vacuum suitable special version of the DSC 404, which determines the determination of heat capacities and heat of transformation with the heat flow method from 0 ° C up to 1400 ° C. These are heating rates of up to 20 K / min possible. The measurement was carried out in argon atmosphere. It shows the advantageous for such compounds relatively low Heat capacity.

Ausserdem angegeben ist die thermische Leitfähigkeit λ, gemessen bei 100 Grad Celsius. Die Wärmeleitfähigkeit wurde nach der Formel λ = α ρ cP (α ist die Temperaturleitfähigkeit, ρ ist Dichte, cP ist Wärmekapazität) ermittelt. Die Messung von Dichte und Wärmekapazität sind oben angeführt. Die Temperaturleitfähigkeit (TLF) wurde mit dem Laserflashverfahren bei bestimmten Temperaturniveaus (Raumtemperatur, 100, 200, 400, 600, 800, 1000 und 1200 °C) gemessen. Bei jeder Temperatur wurden 5-10 Einzelmessungen durchgeführt. Hieraus wurde ein Mittelwert der TLF bei der ebenfalls gemittelten Temperatur berechnet. Für die Messung der TLF wurde eine Laserflash-Anlage von Netzsch benutzt (Deutschland, Messungen bis 2000 °C sind möglich). Da der Probenraum hermetisch vom Ofenraum abgeschlossen ist, können Messungen im Vakuum durchgeführt werden. Der Festkörperlaser hat eine Wellenlänge von 1064 nm und eine maximale Energieabgabe von ca. 20 Joule pro Schuss. Die Pulsdauer lässt sich von 0,2 bis 1,2 ms variieren. Die in Figur 6 angegebene thermische Diffusivität α wurde unter Verwendung der Laserblitzmethode (laser flash method) in der ACCESS Einrichtung (E. Pfaff. Bericht 72-00 (20.09.2000) of Rheinisch-Westfälische Technische Hochschule Aachen) ausgemessen.Also stated is the thermal conductivity λ, measured at 100 degrees Celsius. The thermal conductivity was calculated according to the formula λ = α ρ c P (α is the thermal diffusivity, ρ is density, c P is heat capacity). The measurement of density and heat capacity are listed above. The temperature conductivity (TLF) was measured by the laser flash method at certain temperature levels (room temperature, 100, 200, 400, 600, 800, 1000 and 1200 ° C). At each temperature, 5-10 individual measurements were made. From this an average value of the TLF at the also averaged temperature was calculated. For the measurement of the TLF, a Laserflash system from Netzsch was used (Germany, measurements up to 2000 ° C are possible). Since the sample chamber is hermetically sealed from the furnace chamber, measurements can be carried out in a vacuum. The solid-state laser has a wavelength of 1064 nm and a maximum energy output of about 20 joules per shot. The pulse duration can be varied from 0.2 to 1.2 ms. The thermal diffusivity α indicated in FIG. 6 was measured using the laser flash method in the ACCESS device (E. Pfaff. Report 72-00 (20.09.2000) of Rheinisch-Westfälische Technische Hochschule Aachen).

Fig. 1 bis 4 zeigen Pulverröntgendiffraktionsmuster der Proben gem. Tabelle 1. Dabei ist die Intensität (I) in Abhängigkeit vom Beugungswinkel (2 Theta) dargestellt. Die Messungen fanden in einem Gerät des PADX Powder Diffraktometer (Scintag, USA), λ von Cu-Strahlung, Ge-Detektor, statt.FIGS. 1 to 4 show powder X-ray diffraction patterns of the samples according to FIG. Table 1. Here the intensity (I) is shown as a function of the diffraction angle (2 theta). The Measurements were taken in a PADX Powder Diffractometer (Scintag, USA), λ of Cu radiation, Ge detector, instead.

Fig. 1 zeigt unterschiedliche Pulverröntgendiffraktionsmuster zur Probe Ti-4. Dabei ist in Fig. 1a) das Diffraktionsmuster für eine in einem Zirkondioxid-Tiegel getemperte Probe Ti-4 dargestellt. Ausserdem sind in den Figuren 1a)-c) mit Vierecken und Pfeilen die Peaks der Struktur α(TiCrSi), d. h. des 1/1 Approximanten der kubischen Struktur Ti75-xCr25Six, wobei 10 < x < 20, angezeigt Ausschliesslich mit Vierecken sind die Peaks, welche zur Struktur Ti5Si3 gehören, angegeben. Es ist somit erkennbar, wie unterschiedliche Strukturen nebeneinander vorliegen. Die Information zur Zuordnung wurde aus J. L. Libbert, J. Y. Kim and K. F. Kelton: Oxygen in Ti(Cr, Mn)-Si Icosahedral Phases and Approximants, Phil. Mag. A, 79, 2209 (1999) bezogen.Fig. 1 shows different powder X-ray diffraction patterns for sample Ti-4. The diffraction pattern for a specimen Ti-4 annealed in a zirconium dioxide crucible is shown in FIG. 1a). In addition, in FIGS. 1a) -c) with quadrilaterals and arrows, the peaks of the structure α (TiCrSi), ie of the 1/1 approximant of the cubic structure Ti 75-x Cr 25 Si x , where 10 <x <20, are indicated Exclusively with squares, the peaks belonging to the structure Ti 5 Si 3 are given. It can thus be seen how different structures exist side by side. The information for assignment was obtained from JL Libbert, JY Kim and KF Kelton: Oxygen in Ti (Cr, Mn) -Si Icosahedral Phases and Approximants, Phil. Mag. A, 79, 2209 (1999).

Fig. 1b) zeigt eine entsprechende Probe, welche in einem Graphit-Tiegel getempert wurde. Fig. 1c) zeigt eine Probe, welche nicht getempert wurde.Fig. 1b) shows a corresponding sample, which is annealed in a graphite crucible has been. Fig. 1c) shows a sample which has not been tempered.

Fig. 2 zeigt entsprechende Diffraktionsmuster der Proben Ti-1 (Fig. 2a, nicht getempert, VACUMET), Ti-2 (Fig. 2b, nicht getempert, VACUMET) sowie Ti-3 (Fig. 2c, nicht getempert, VACUMET). Mit dem Begriff VACUMET ist das Schmelzen der Ti-Legierungen im Induktionsofen im Vakuum mit geringem Argon-Partialdruck (15 Torr) in speziell präparierten Graphittiegeln bezeichnet. Auch hier können wiederum die einzelnen Phasen nebeneinander zugeordnet werden.FIG. 2 shows corresponding diffraction patterns of the samples Ti-1 (FIG. 2a, not annealed, FIG. VACUMET), Ti-2 (Figure 2b, not annealed, VACUMET) and Ti-3 (Figure 2c, not annealed, VACUMET). The term VACUMET is the melting of Ti alloys in the induction furnace in vacuum with low argon partial pressure (15 Torr) designated in specially prepared graphite crucibles. Again, the individual phases are assigned next to each other.

Fig. 3 zeigt die Diffraktionsmuster der Probe Ti-2, wobei a) eine getemperte Probe darstellt, b) eine nicht-getemperte Probe und c) eine nicht-getemperte Probe im VACUMET-Verfahren.Fig. 3 shows the diffraction patterns of the sample Ti-2, wherein a) a tempered sample b) a non-annealed sample; and c) a non-annealed sample in the VACUMET method.

Auch hier ist das nebeneinander der unterschiedlichen Strukturen klar erkennbar. Ausserdem sind im Falle dieser Probe die Unterschiede zwischen den getemperten und den nicht getemperten Proben erkennbar respektive es ist sichtbar, dass eine Temperung eine zumindest in Bezug auf das Diffraktionsmuster ähnliche Struktur erzeugt wie ein Verfahren gemäss VACUMET.Again, the juxtaposition of different structures is clearly visible. In addition, in the case of this sample, the differences between the annealed and the non-tempered samples visible respectively it is visible that a heat treatment produces a structure similar at least with respect to the diffraction pattern like a Process according to VACUMET.

Fig. 4 zeigt die entsprechenden Diffraktionsmuster für unterschiedliche Herstellungsverfahren der Probe Ti-3 (a: getempert ; b: nicht getempert, VACUMET). Auch hier kann erkannt werden, wie diese beiden Herstellungsweisen ähnliche Strukturen zumindest in Bezug auf die Diffraktionsmuster ergeben.Fig. 4 shows the corresponding diffraction patterns for different ones Method of preparation of sample Ti-3 (a: annealed, b: unannealed, VACUMET). Again, it can be seen how similar these two ways of production Structures arise at least in relation to the diffraction pattern.

Wie in Fig. 5 dargestellt, wurden die Proben ausserdem in einem "in-lens" fieldemission scanning Elektronenmikroskop des Typs Hitachi S-900 mit einer Beschleunigungsspannung von 30kV untersucht, wobei ein Standard-Everhard-Thornley SE Detektor und ein YAG type BSE-Detektor verwendet wurden. Aus den Backscattering-Mustern der Fig. 5a) und b) werden die unterschiedlichen Strukturen respektive die Grösse der Domänen sichtbar. Die hell abgebildeten Bereiche bezeichnen die alpha-Phase, die dunklen Bereiche die Phase aus Ti5Si3. Es ist erkennbar, dass bei der Probe Ti-2 (Fig. 5a) grössere Domänen entstehen als bei der Probe Ti-4. Beide Bilder sind Bilder der Oberfläche und beziehen sich auf Messungen von getemperten Proben.As shown in Fig. 5, the samples were further examined in a Hitachi S-900 "in-lens" field emission scanning electron microscope with an acceleration voltage of 30kV using a standard Everhard-Thornley SE detector and a YAG type BSE detector were used. From the backscattering patterns of Fig. 5a) and b) the different structures and the size of the domains are visible. The light-colored areas denote the alpha phase, the dark areas the phase of Ti 5 Si 3 . It can be seen that larger domains are formed in sample Ti-2 (FIG. 5a) than in sample Ti-4. Both images are images of the surface and refer to measurements of annealed samples.

Fig. 5c) zeigt ein normales SEM-Bild der Probe Ti-2, nachdem sie bei 800 Grad Celsius unter Luft während 500 Stunden oxidiert wurde. Die oberste, helle Schicht ist eine Schicht aus TiO2, die darunter liegende Zwischenschicht besteht aus CrO2, wobei u. U. dazwischen eine Adhäsionsschicht angeordnet ist. Im untersten Bereich am unteren Rand der Abb. ist die Legierung selber dargestellt. Fig. 5d) zeigt eine Backscattering-Aufnahme der identischen Probe. Es handelt sich bei den Figuren 5c) und d) um Bilder von Schnitten senkrecht zur Oberfläche der Proben.Fig. 5c) shows a normal SEM image of the sample Ti-2 after being oxidized at 800 degrees Celsius under air for 500 hours. The uppermost, light layer is a layer of TiO 2 , the underlying intermediate layer consists of CrO 2 , where u. U. between an adhesion layer is arranged. The lower part of the picture shows the alloy itself. Fig. 5d) shows a backscattering image of the identical sample. Figures 5c) and d) are images of sections perpendicular to the surface of the samples.

Figur 6 zeigt die thermische Diffusivität der Proben Ti-1 (Bezugszeichen 11), Ti-2 (Bezugszeichen 12), Ti-3 (Bezugszeichen 13). Die thermische Diffusivität ist eine Materialeigenschaft welche die Geschwindigkeit abbildet, mit welcher Wärme durch einen Körper diffundiert. Sie ist eine Funktion der thermischen Leitfähigkeit des Körpers sowie von dessen Wärmekapazität. Eine hohe thermische Leitfähigkeit erhöht die thermische Diffusivität des Körpers, da sie eine schnelle Wanderung der Wärme durch den Körper erlaubt. Auf der anderen Seite wird eine grosse Wärmekapazität die thermische Diffusivität des Körpers erniedrigen, da transportierte Wärme bevorzugt im Körper gespeichert wird und nicht durch diesen weitergeleitet wird. Aus Figur 6 wird ersichtlich, wie insbesondere die Probe Ti-2 gerade bei hohen Temperaturen eine niedrige thermische Diffusivität aufweist, was für die vorgeschlagenen Verwendungen vorteilhaft ist. Grundsätzlich wird wie üblich eine zunehmende thermische Diffusivität für zunehmende Temperatur festgestellt.FIG. 6 shows the thermal diffusivity of the samples Ti-1 (reference numeral 11), Ti-2 (Reference 12), Ti-3 (Reference 13). The thermal diffusivity is one Material property which depicts the speed with which heat passes through a body diffuses. It is a function of the thermal conductivity of the Body as well as its heat capacity. A high thermal conductivity increases the thermal diffusivity of the body, as it allows a rapid migration of heat allowed by the body. On the other hand, a large heat capacity is the reduce thermal diffusivity of the body, as transported heat preferably in Body is stored and not forwarded by this. From Figure 6 is can be seen, in particular the sample Ti-2 just at high temperatures has low thermal diffusivity, which is for the proposed uses is advantageous. Basically, as usual, increasing thermal diffusivity noted for increasing temperature.

Fig. 7 zeigt die thermische Leitfähigkeit der Proben Ti-1 (Bezugszeichen 11), Ti-2 (Bezugszeichen 12), Ti-3 (Bezugszeichen 13), sowie Ti-4 (Bezugszeichen 14). Fig. 7 shows the thermal conductivity of the samples Ti-1 (reference numeral 11), Ti-2 (Reference 12), Ti-3 (Reference 13), and Ti-4 (Reference 14).

Wiederum ist die besonders für die Probe Ti-2 niedrige thermische Leitfähigkeit zu beobachten. Es muss aber darauf hingewiesen werden, dass die thermische Leitfähigkeit einer entsprechenden Schicht aus YSZ noch niedriger wäre, eine derartige Schicht ist aber wesentlich spröder und mechanisch wesentlich weniger stabil als sämtliche der vorgeschlagenen Legierungen, die für Metalle typische duktile Eigenschaften haben. Grundsätzlich zeigt sich eine nicht ausgeprägt stark variierende thermische Leitfähigkeit über den beobachteten und relevanten Temperaturbereich.Again, the low thermal conductivity is especially low for Sample Ti-2 observe. It must be noted, however, that the thermal conductivity a corresponding layer of YSZ would be even lower, such a layer is but much more brittle and mechanically much less stable than all of the proposed alloys which have typical ductile properties for metals. Basically, there is a not very strongly varying thermal conductivity over the observed and relevant temperature range.

Figur 8 zeigt die thermische Leitfähigkeit einer Vielzahl von Proben, wie sie in der Bezugszeichenliste zusammengestellt sind. Es kann erkannt werden, dass die thermische Leitfähigkeit der Vergleichsprobe Ti-2 (Bezugszeichen 10) im mittleren Bereich angesiedelt ist. Typische Proben aus YSZ (yttrium stabilized ZnO2) verfügen über niedrigere Werte ebenso entsprechende AlCo-Legierungen (Bezugszeichen 5-7). Wie bereits im Zusammenhang mit der Fig. 7 erwähnt, verfügen aber diese Proben über schlechtere mechanische Eigenschaften als die vorgeschlagenen Verbindungen.FIG. 8 shows the thermal conductivity of a plurality of samples, as summarized in the list of reference numerals. It can be seen that the thermal conductivity of the comparative sample Ti-2 (reference numeral 10) is located in the middle region. Typical samples of YSZ (yttrium stabilized ZnO 2 ) have lower values as well as corresponding AlCo alloys (reference numerals 5-7). As already mentioned in connection with FIG. 7, however, these samples have worse mechanical properties than the proposed compounds.

Fig. 9 zeigt Pulverdiffraktionsmuster der Probe Ti-2, wobei Messungen nach unterschiedlichen Zeiten der Oxidation vorgenommen wurden. Es handelt sich dabei um eine Probe, welche vor deren Oxidation in einem Verfahren mit Temperung hergestellt worden war. Die Oxidation fand dabei unter Luft bei 950 Grad Celsius statt. Es kann erkannt werden, wie sukzessive Oxide an der Oberfläche entstehen, wie sich aber der Zustand im wesentlichen nach ca. 50 Stunden stabilisiert. Fig. 10 zeigt die entsprechenden Muster der gleichen Probe, wobei in diesem Fall die Oxidation bei 1100 Grad Celsius durchgeführt worden ist. Man findet ein ähnliches Verhalten wie bei Fig. 9. Die Oxidationskinetik wurde ebenfalls untersucht und ist in Fig. 11 dargestellt. Da eine langsame Oxidation bevorzugt ist, erweist sich gemäss Fig. 11a) die bei 800 Grad Celsius getemperte Probe als herausragend. Die Temperung fand dabei während einer Zeit von statt. Als Vergleichsmaterial wurde TiAl angegeben. Insbesondere aus Figur 11b) kann die Überlegenheit von Proben, welche getempert wurden, erkannt werden, wobei eine Temperung bei niedriger Temperatur üblicherweise eine grössere Stabilität in Bezug auf Oxidation nach zu ziehen scheint. Fig. 9 shows powder diffraction pattern of the sample Ti-2, wherein measurements after different times of oxidation were made. It is about a sample prepared prior to its oxidation in a tempering process had been. The oxidation took place under air at 950 degrees Celsius. It can be recognized how successive oxides are formed on the surface, but how the Condition substantially stabilized after about 50 hours. Fig. 10 shows the corresponding pattern of the same sample, in which case the oxidation at 1100 Degrees Celsius has been performed. One finds a similar behavior as in FIG. 9. Oxidation kinetics were also investigated and shown in FIG. 11. There a slow oxidation is preferred, turns out according to FIG. 11a) at 800 degrees Celsius tempered sample as outstanding. The tempering found during a Time of place. As a comparison material TiAl was given. In particular from FIG 11b), the superiority of samples which have been annealed can be recognized, wherein low temperature annealing usually provides greater stability in terms of oxidation seems to be.

BEZUGSZEICHENLISTELIST OF REFERENCE NUMBERS

11
YSZ, PVDYSZ, PVD
22
YSZ, PlasmasprayYSZ, plasma spray
33
YSZ, gesintertYSZ, sintered
44
rostfreier Stahlstainless steel
55
Al71.1Co13Fe8Cr8 Al 71.1 Co 13 Fe 8 Cr 8
66
Al70.1Co14Ni16, geheiztAl 70.1 Co 14 Ni 16 , heated
77
Al71.1Co13Ni15.2+Al74.2Co12.4Ni13.4, geheiztAl 71.1 Co 13 Ni 15.2 + Al 74.2 Co 12.4 Ni 13.4 , heated
88th
Ni-LegierungNi alloy
99
Ti-LegierungTi alloy
1010
Probe Ti-2Sample Ti-2
1111
Ti-1Ti-1
1212
Ti-2Ti-2
1313
Ti-3Ti-3
1414
Ti-4Ti-4
1515
Ti-2, bei 800 Grad Celsius getempertTi-2, annealed at 800 degrees Celsius
1616
Ti-2, bei 950 Grad Celsius getempertTi-2, annealed at 950 degrees Celsius
1717
TiAl, bei 800 Grad Celsius getempertTiAl, tempered at 800 degrees Celsius
1818
TiAl, bei 950 Grad Celsius getempertTiAl, tempered at 950 degrees Celsius
1919
Ti-2, ohne Tempern, bei 950 Grad Celsius gegossenTi-2, without annealing, poured at 950 degrees Celsius
2020
Ti-2, bei 950 Grad Celsius ausgeglühtTi-2, annealed at 950 degrees Celsius
2121
Ti-2, ohne Tempern, bei 1050 Grad Celsius gegossenTi-2, without annealing, cast at 1050 degrees Celsius
2222
Ti-2, bei 1050 Grad Celsius ausgeglühtTi-2, annealed at 1050 degrees Celsius

Claims (13)

  1. Icosahedral, quasicrystalline compound or compound present in the form of an approximant having the nominal composition: TivCrwAlxSiyOz in which
    v = 60-65
    w = 25-30
    x = 0-6
    y = 8-15
    z = 8-20
    and in which
    the atom percent of oxygen is in the range of 8 to 15%, and that of aluminium is in the range of 2 to 5%.
  2. Compound according to Claim 1, characterized in that
    v = 60
    w = 30
    x = 0-3
    y = 8-15, 8-10 being especially preferred
    z = 8-20, 8-10 being especially preferred
    in which the atom percent of oxygen is in the range of 8 to 12%, and that of aluminium is in the range of 1.5 to 3%.
  3. Compound according to one of the preceding claims,
    characterized in that
    v = 60
    w = 30
    x = 0-2
    y = 8-10
    in which the atom percent of oxygen is in the region of 10%, and that of aluminium is in the range of 1.5 to 2.5%.
  4. Compound according to one of the preceding claims,
    characterized by at least one of the following compositions: Ti60Cr32Si4(SiO2)4; Ti60Cr25Si5(SiO2)10; Ti65Cr25Si2.5(SiO2)7.5; Ti60Cr30(SiO2)10; Ti60Cr30Al2Si3(SiO2)5; Ti60Cr30Al3Si2(SiO2)5; Ti60Cr30Al2Si3(SiO)5; Ti60Cr30Si5(SiO2)5.
  5. Method for manufacturing a compound according to one of Claims 1 to 4, characterized in that the components are fused in a protective gas or vacuum.
  6. Method according to Claim 5, characterized in that fusion is carried out in an arc.
  7. Method according to one of Claims 5 or 6, characterized in that the compound, after being fused, is tempered especially preferably in a furnace, preferably at a temperature in the range of 1000 to 1300°C for a period of 80 to 200 hours, in which preferably said compound is tempered for 7 days at 1100°C, and is subsequently cooled in the furnace.
  8. Method according to Claim 7, characterized in that tempering occurs in steps, in which a scheme involving graduated increases or one involving graduated decreases in temperature, or a combination of such schemata, can be employed.
  9. Method according to one of Claims 5 to 8, characterized in that the compound is applied as a coating to a material, in which methods employing plasma spraying or vapour deposition may be used in particular, followed optionally by tempering.
  10. Use of a compound according to one of Claims 1 to 4, which is preferably manufactured according to one of the methods according to Claim 5 to 9, as a material for a component that is exposed to high temperatures, and which in particular is exposed to or surrounded by hot gases.
  11. Use of a compound according to Claim 10, characterized in that such use involves a component of a gas turbine or of a compressor, with a rotor blade or guide vane of a gas turbine or compressor being especially preferred.
  12. Use according to one of Claims 10 or 11, characterized in that the compound is present as a coating especially preferably on the surface directly exposed to hot gases, in which a further functional layer may optionally be disposed underneath the coating, in particular for providing adhesion and as an additional barrier.
  13. Use according to Claim 12, characterized in that the coating has a thickness in the range of 10-400 µm, with a range of 100 to 200 µm being especially preferred.
EP04101277A 2003-03-31 2004-03-29 Quasicrystalline Ti-Cr-Al-Si-O alloy and its use as a coating Expired - Lifetime EP1464716B1 (en)

Applications Claiming Priority (2)

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US10/401,696 US7060239B2 (en) 2003-03-31 2003-03-31 Quasicrystalline alloys and their use as coatings
US401696 2003-03-31

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EP1464716A8 EP1464716A8 (en) 2004-12-29
EP1464716B1 true EP1464716B1 (en) 2005-12-28

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EP (1) EP1464716B1 (en)
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102012219856A1 (en) * 2012-10-30 2014-04-30 Siemens Aktiengesellschaft Turbine blade and method for producing a turbine blade with high surface hardness

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN210227766U (en) * 2018-07-27 2020-04-03 佛山市顺德区美的电热电器制造有限公司 Frying pan
CN113956689B (en) * 2018-11-02 2023-07-21 佛山市顺德区美的电热电器制造有限公司 Method and system for forming quasicrystal coating and pot

Family Cites Families (2)

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Publication number Priority date Publication date Assignee Title
US5256369A (en) * 1989-07-10 1993-10-26 Nkk Corporation Titanium base alloy for excellent formability and method of making thereof and method of superplastic forming thereof
DE59106459D1 (en) 1990-05-04 1995-10-19 Asea Brown Boveri High temperature alloy for machine components based on doped titanium aluminide.

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102012219856A1 (en) * 2012-10-30 2014-04-30 Siemens Aktiengesellschaft Turbine blade and method for producing a turbine blade with high surface hardness

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EP1464716A8 (en) 2004-12-29
EP1464716A1 (en) 2004-10-06
US20040191154A1 (en) 2004-09-30
DE502004000215D1 (en) 2006-02-02
US7060239B2 (en) 2006-06-13

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