Heat treatable L12 aluminum alloys
AssigneeUnited Technologies Corporation
InventorAwadh B. Pandey
Life of this patent
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Abstract
High temperature heat treatable aluminum alloys that can be used at temperatures from about −420° F. (−251° C.) up to about 650° F. (343° C.) are described. The alloys are strengthened by dispersion of particles based on the L12 intermetallic compound Al3X. These alloys comprise aluminum; silicon; at least one of scandium, erbium, thulium, ytterbium, and lutetium; and at least one of gadolinium, yttrium, zirconium, titanium, hafnium, and niobium. Magnesium and copper are optional alloying elements.
Claims27
A heat treatable aluminum alloy comprising:
- about 4.0 to about 25.0 weight percent silicon;
- at least one first element selected from the group comprising about 0.1 to about 0.5 weight percent scandium, about 0.1 to about 6.0 weight percent erbium, about 0.1 to about 10 weight percent thulium, about 0.1 to about 15.0 weight percent ytterbium, and about 0.1 to about 12 weight percent lutetium;
- at least one second element selected from the group comprising about 0.1 to about 4.0 weight percent gadolinium, about 0.1 to about 4.0 weight percent yttrium, about 0.05 to about 1.0 weight percent zirconium, about 0.05 to about 2.0 weight percent titanium, about 0.05 to about 2.0 weight percent hafnium, and about 0.05 to about 1.0 weight percent niobium;
- and
- the balance substantially aluminum.
A heat treatable aluminum alloy comprising:
- about 4.0 to about 25.0 weight percent silicon;
- and
- an aluminum solid solution matrix containing a plurality of dispersed Al3X second phases having L12 structures where X comprises at least one of scandium, erbium, thulium, ytterbium, lutetium, and at least one of gadolinium, yttrium, zirconium, titanium, hafnium, niobium.
A method of forming a heat treatable aluminum alloy, the method comprising:
- (a) forming a melt comprising:
- about 4.0 to about 25.0 weight percent silicon;
- about 0.2 to about 3.0 weight percent magnesium;
- about 0.5 to about 5.0 weight percent copper;
- at least one first element selected from the group comprising about 0.1 to about 0.5 weight percent scandium, about 0.1 to about 6.0 weight percent erbium, about 0.1 to about 10 weight percent thulium, about 0.1 to about 15.0 weight percent ytterbium, and about 0.1 to about 12 weight percent lutetium;
- at least one second element selected from the group comprising about 0.1 to about 4.0 weight percent gadolinium, about 0.1 to about 4.0 weight percent yttrium, about 0.05 to about 1.0 weight percent zirconium, about 0.05 to about 2.0 weight percent titanium, about 0.05 to about 2.0 weight percent hafnium, and about 0.05 to about 1.0 weight percent niobium;
- and
- the balance substantially aluminum;
- (b) solidifying the melt to form a solid body;
- and
- (c) heat treating the solid body.
Dependencies are inferred from the claim text.