Classifications

• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C30/00—Alloys containing less than 50% by weight of each constituent
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C1/00—Making non-ferrous alloys
  • C22C1/04—Making non-ferrous alloys by powder metallurgy
  • C22C1/0408—Light metal alloys
  • C22C1/0416—Aluminium-based alloys
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C1/00—Making non-ferrous alloys
  • C22C1/04—Making non-ferrous alloys by powder metallurgy
  • C22C1/045—Alloys based on refractory metals
  • C22C1/0458—Alloys based on titanium, zirconium or hafnium
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C14/00—Alloys based on titanium
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C21/00—Alloys based on aluminium
  • C22C21/003—Alloys based on aluminium containing at least 2.6% of one or more of the elements: tin, lead, antimony, bismuth, cadmium, and titanium
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
  • B22F2998/00—Supplementary information concerning processes or compositions relating to powder metallurgy
  • B22F2998/10—Processes characterised by the sequence of their steps

Definitions

• the invention relates to a method for producing an alloy based on titanium aluminides.
• Alloys based on titanium aluminides prepared using melt and powder metallurgy techniques with a predetermined alloy composition of titanium and aluminum and optionally other constituents, e.g. Niobium, boron, chromium, molybdenum, manganese and vanadium etc. as well as carbon in different compositions are known in the art.
• Titanium-aluminide alloys have properties that are particularly favorable for use as a lightweight material, in particular for high-temperature applications. These lightweight materials based on titanium aluminides open due to their strength and creep properties at high temperatures Possibilities for the production of mechanically stressed components in the high temperature technology, eg as turbine blades in the aircraft industry, final stage blades, engine valves, etc. In addition, they offer because of their low density (about 3.8 - 4.3 g / cm 3 ) as a substitute for nickel base Superalloys, which typically have a density of 8.5 g / cm 3 .
• Amounts of halogens in the surface of Titanaluminid- materials significantly improve the oxidation behavior due to the so-called halogen effect, whereby the range of application of the materials to temperatures above 1000 0 C is extended.
• DE-A-103 51 946 discloses a method of treating the surface of a titanium aluminide alloy-containing member to improve its oxidation resistance.
• DE-C-196 27 605 discloses a method of increasing corrosion resistance for alloys on the
• the present invention seeks to provide titanium aluminide alloys having a high oxidation resistance, wherein at
• the object is to provide a component of a corresponding titanium aluminide alloy.
• the object is achieved by a method for producing an alloy based on titanium aluminides, wherein metal droplets are obtained from a titanium aluminide molten metal, in particular using the gas atomization method, by applying a halogen-containing metal droplet
• the produced component is or is maintained, as well as in depth by the introduced, in particular homogeneously distributed or evenly distributed random halogens in the alloy or in the material, the oxidation resistance of the entire alloy is maintained.
• Chlorine and / or fluorine are preferably introduced as halogens into the bulk material prepared from titanium aluminide.
• further halogens e.g. of iodine and / or bromine possible.
• hot isostatic pressing achieves an alloy with high isotropy and uniform compaction of the material.
• the process of hot isostatic pressing takes place at very high pressures, e.g. 100 Mpa and under high temperatures, e.g. between
• the molten metal and / or the metal droplets are treated by means of a carrier gas, preferably by means of an inert gas, wherein in particular the
• Carrier gas is mixed with the halogen-containing gas or is.
• inert gases such as argon or helium or other inert gases have proven to be effective, whereby when mixed with a halogen-containing gas, the molten metal is treated specifically to enrich the metal droplets with halogens.
• a titanium-aluminide-metal powder is formed, from which the alloy is formed. This is usually done by hot isostatic pressing.
• a component is produced from the shaped alloy which has a high resistance to oxidation even if the surface of the component is damaged.
• the components may be components for example from the automotive, aerospace, aircraft and industrial machine tools sector.
• the object is achieved by a method for producing an alloy based on titanium aluminides, wherein titanium-containing powder and aluminum-containing powder or titanium powder and aluminum powder and / or powdered titanium aluminide, in particular titanium aluminide metal powder, by means of or in are ground in a mill, preferably by means of or in a ball mill, wherein in the mill, in particular ball mill, a halogen-enriched atmosphere is provided during the grinding process or, so that during the grinding process, halogen-enriched titanium aluminide metal powder is formed and then the halogenated powdered titanium aluminide is formed into an alloy by preferably hot isostatic pressing.
• the metal powder has an intensive contact with ball milling and introduction of gases in the ball mill, a, in particular homogeneous, enrichment of powdered titanium aluminide is also achieved, whereby the halogens are distributed throughout the alloy produced or formed.
• the distribution of the halogens in the alloy is such that the (relative) content in any predetermined volume or partial volume or even in small partial volume of the finished alloy Halogens (per volume) is almost constant or kept constant.
• Powder form or in addition to the pre-alloyed metal powder and elemental powdered titanium and elemental powdered aluminum use or provide, so that by the grinding process both from the titanium powder and the aluminum powder, a TiAl alloy is formed in powder form, due to the presence of the halogen-containing gas at a high Pressure in the ball mill in the ball mill is or will be enriched in its halogen content.
• the halogen-enriched atmosphere is provided as a gaseous and / or liquid atmosphere, whereby an intensive exchange or intensive accumulation of the powder in the gaseous or in the liquid, halogen-containing atmosphere, such as in liquid carbon tetrachloride ( CCI 4 ).
• the halogen-enriched atmosphere in particular gaseous atmosphere, with at least one inert gas, such as argon or helium provided.
• a component is produced from the alloy with a constant (relative) proportion of halogens in each volume or partial volume or volume of the alloy.
• a process for producing a titanium aluminide-based alloy wherein powdered titanium aluminide, especially titanium-aluminide-metal powder, is heated in a preferably closed container for a predetermined period of time, wherein A halo-enriched atmosphere is provided so as to form a halogen-enriched titanium aluminide metal powder during the heating period, and then alloying the halogen-enriched titanium aluminide metal powder by preferably hot isostatic pressing.
• titanium aluminide alloys are also prepared in which halogens are added to the entire material, wherein the (relative) proportion of halogens (by volume) in the alloy over the entire volume or in a (small) subvolume of the
• the proportion of halogens may vary with a typical fluctuation range of ⁇ 15%, preferably ⁇ 10%, more preferably ⁇ 5%, since the proportion of halogens in the alloy typically between 0.005 at% to 1.5 at%, preferably between
• halogens in addition to fluorine and / or chlorine, in a Alloy are distributed, other halogens such as bromine and / or iodine can be used.
• a halogen-containing gas is understood to mean a gas which, in addition to other gases, preferably inert gases, has both a halogen element and a mixture of several halogen elements.
• the pulverulent titanium aluminide, in particular titanium aluminide metal powder is subjected to a vacuum in the container.
• a further method step in the gassing of the metal powder is characterized in that the atmosphere enriched with halogens with at least one inert gas, in particular after evacuation of the container is provided.
• the container and / or the powdery titanium aluminide to a temperature between 300 0 C to 1300 0 C 1 are preference, between 500 ° C to 1000 0 C, heated, whereby a good
• the process steps evacuate, gassing and heating can also be performed several times in succession to a higher
• the powdered titanium aluminide in particular titanium aluminide metal powder, with negative pressure or a
• the object is achieved by a component which is or is made of an alloy which is produced by one of the said methods or method steps.
• Titanium aluminide alloys are preferably produced using casting metallurgy or powder metallurgy techniques, titanium being used to carry out the processes.
• aluminide alloys in powder form are present in order to add the metal powders according to the invention with halogens.
• Components made of titanium aluminides are customarily produced by the known shaping methods and atomization methods.
• the TiAl-based intermetallic compounds may be alloys having a general composition of titanium and aluminum according to the desired and predetermined requirements in the art
• Titanium aluminide alloys prepared according to the presented process of the present invention may generally comprise, for example, between 30 atomic% to 70 atomic% aluminum, with further additional substances or elements, which are mentioned below, corresponding to the desired alloying requirements or the material to be recorded.
• the alloys may have aluminum contents between 44 at% to 49 at% of Al.
• other ingredients such as e.g. Chromium (Cr), niobium (Nb), manganese (Mn), vanadium (V), tantalum (Ta), molybdenum (Mo), zirconium (Zr), tungsten
• Alloys which are based on the intermetallic phase ⁇ (TiAl) of a tetragonal structure are also of particular interest for industrial practice.
• These ⁇ -titanium aluminide alloys are characterized by properties such as a low density (3.85 to 4.3 g / cm 3 ), high elastic modulus and high strength and creep resistance up to 700 0 C.
• a particularly high-strength titanium aluminide alloy is an alloy composition of titanium, aluminide and niobium, to which optional components of boron and / or carbon are added, the proportion of boron and / or carbon in the alloy being below a concentration of 0.5 atom%. is selected.
• the titanium aluminide alloy has a composition of Ti - 45 at% Al-x Nb at 5 at% ⁇ x ⁇ 10 at% and optionally up to 0.5 at% B (boron) and / or up to 0.5 atom % C (carbon).
• the abovementioned alloy likewise contains boron, preferably with a boron content in the alloy in the range from 0.05 atom% to 0.8 atom%.
• the addition of boron advantageously leads to the formation of stable precipitates which contribute to the mechanical hardening of the alloy according to the invention and stabilization of the microstructure of the alloy.
• the alloy contains carbon, preferably with a carbon content in the range of 0.05 at% to 0.8 at%.
• carbon preferably in combination with the above-mentioned additive boron, leads to the formation of stable precipitates, which also for mechanical hardening of the alloy and the
• an alloy based on titanium aluminides produced using fusion and powder metallurgy techniques and having an alloy composition of Ti - Al - y Nb - x B having 44.5 at% ⁇ z ⁇ 47 at%, especially at 44.5 at % ⁇ z ⁇ 45.5 at%, 5 at% ⁇ y ⁇ 10 at% and 0.05 at% ⁇ x ⁇ 0.8 at%, said molybdenum (Mo) being in the range of 0.1 atomic% to 3 Atom%, a titanium aluminide alloy is provided with a fine and homogeneous grain morphology to form a stable ⁇ -phase at high temperatures above 700 0 C.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Powder Metallurgy (AREA)
• Manufacture Of Metal Powder And Suspensions Thereof (AREA)

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• 2007
  • 2007-07-10 DE DE102007032406A patent/DE102007032406B3/de not_active Expired - Fee Related
• 2008
  • 2008-04-21 EP EP08749011A patent/EP2185738B1/fr not_active Not-in-force
  • 2008-04-21 AT AT08749011T patent/ATE546556T1/de active
  • 2008-04-21 CN CN2008800238258A patent/CN101796205B/zh not_active Expired - Fee Related
  • 2008-04-21 JP JP2010515354A patent/JP2010532822A/ja active Pending
  • 2008-04-21 WO PCT/EP2008/003173 patent/WO2009006954A2/fr active Application Filing
  • 2008-04-21 ES ES08749011T patent/ES2378254T3/es active Active
• 2010
  • 2010-01-08 US US12/684,176 patent/US20100119402A1/en not_active Abandoned

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