High temperature resistant TiAl alloy, production method therefor and component made therefrom
AssigneeMTU Aero Engines AG
InventorsWilfried Smarsly, Martin Schloffer, Helmut Clemens, Thomas Klein
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Abstract
Described is a TiAl alloy which, besides titanium, comprises 42 to 48 at. % aluminum, 3 to 5 at. % niobium, 0.05 to 1 at. % molybdenum, 0.2 to 2.2 at. % silicon, 0.2 to 0.4 at. % carbon, 0.05 to 0.2 at. % boron, and optionally tungsten, zirconium and hafnium, as well as unavoidable impurities, and at room temperature has a microstructure which comprises globular colonies of lamellae of α2-Ti3Al and γ-TiAl, as well as silicide precipitates, and essentially no β phase. A method for producing a component made of this alloy is also described.
Claims20
A TiAl alloy, wherein the alloy comprises
- from 43.5 to 45 at. % aluminum,
- from 3.5 to 4.5 at. % niobium,
- from 0.1 to 0.5 at. % molybdenum,
- from 0.4 to 1 at. % tungsten,
- from 0.25 to 0.35 at. % silicon,
- from 0.25 to 0.35 at. % carbon,
- from 0.05 to 0.15 at. % boron,
- and unavoidable impurities, titanium being provided in a quantity such that the sum of proportions of chemical elements amounts to 100 at. %, and the TiAl alloy having at room temperature a microstructure which comprises globular colonies of lamellae of α2-Ti3Al and γ-TiAl, as well as silicide precipitates, and essentially no β phase.
A TiAl alloy, wherein the alloy comprises
- from 43.5 to 45 at. % aluminum,
- from 3.5 to 4.5 at. % niobium,
- from 0.85 to 0.95 at. % molybdenum,
- from 0.1 to 3 at. % zirconium,
- from 0.25 to 2.2 at. % silicon,
- from 0.25 to 0.35 at. % carbon,
- from 0.05 to 0.15 at. % boron,
- and unavoidable impurities, titanium being provided in a quantity such that the sum of proportions of chemical elements amounts to 100 at. %, and the TiAl alloy having at room temperature a microstructure which comprises globular colonies of lamellae of α2-Ti3Al and γ-TiAl, as well as silicide precipitates, and essentially no β phase.
A TiAl alloy, wherein the alloy comprises
- from 46 to 48 at. % aluminum,
- from 3.5 to 5 at. % niobium,
- from 0.1 to 0.5 at. % molybdenum,
- from 0.4 to 1.8 at. % tungsten,
- from 0.1 to 3 at. % zirconium,
- from 0.35 to 2.2 at. % silicon,
- from 0.25 to 0.35 at. % carbon,
- from 0.05 to 0.15 at. % boron,
- and unavoidable impurities, titanium being provided in a quantity such that the sum of proportions of chemical elements amounts to 100 at. %, and the TiAl alloy having at room temperature a microstructure which comprises globular colonies of lamellae of α2-Ti3Al and γ-TiAl, as well as silicide precipitates, and essentially no β phase.
A method for producing a component made of a TiAl alloy, wherein the method comprises
- melting a TiAl alloy which comprises
- titanium,
- from 42 to 48 at. % aluminum,
- from 3 to 5 at. % niobium,
- from 0.05 to 1 at. % molybdenum,
- from 0.2 to 2.2 at. % silicon,
- from 0.2 to 0.4 at. % carbon,
- from 0.05 to 0.2 at. % boron,
- 0 to 2.0 at. % tungsten,
- 0 to 3.5 at. % zirconium,
- 0 to 0.3 at. % hafnium,
- and unavoidable impurities, titanium being provided in a quantity such that the sum of proportions of chemical elements amounts to 100 at. %, with the proviso that the alloy comprises
- (i) at least 46 at. % aluminum;
- and/or
- (ii) not more than 0.5 at. % molybdenum;
- and/or
- (iii) at least one of tungsten, zirconium, and hafnium;
- casting the melted TiAl alloy to form a semifinished product or atomizing the TiAl alloy to form a powder,
- precipitation-stabilizing the semifinished product, or a preliminary product produced from the semifinished product or the powder, by cooling the semifinished product or the preliminary product from a silicide starting temperature so that silicides are precipitated,
- heat-treating the precipitation-stabilized semifinished product or preliminary product in the α phase temperature range, in which silicide precipitates are present, for from 0.5 to 2 hours and cooling, so that globular colonies of lamellae of α2-Ti3Al and γ-TiAl are formed.
Dependencies are inferred from the claim text.