Method of producing Al-Li alloys with improved properties and product
AssigneeNovamet, Inc.
InventorJohn H. Weber
Life of this patent
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Abstract
A method is provided for producing dispersion-strengthened mechanically alloyed Al-Li alloys with improved mechanical properties. The method comprises subjecting mechanically alloyed, degassed, consolidated Al-Li powders consisting essentially of from above 1.5% up to about 3.5% lithium from about 0.4% up to about 1.5% oxygen, from about 0.2% up to about 1.2% carbon and the balance essentially aluminum, to a heat treatment which will produce an aging response in the alloy.
Claims14
A method for producing a dispersion-strengthened aluminum-base alloy of improved mechanical and thermal properties comprising degassing and compacting at elevated temperature below liquation temperature a mechanically alloyed powder consisting essentially of aluminum, lithium, oxygen and carbon, and optionally one or more of the group selected from magnesium, copper and iron, the lithium level being at least about 1.7 up to about 3.5 weight %, the dispersoid comprising the carbon and oxygen, and being present in a small but effective amount for increased strength up to about 8 volume %, and the balance, apart from said optional components, essentially aluminum, and subjecting the compacted powder to a solution treatment at a temperature not exceeding the maximum degassing and/or compaction temperature, cooling the solution treated alloy, and aging the alloy at an elevated temperature for a period of time sufficient to permit age hardening of the alloy.
A dispersion strengthened mechanically alloyed aluminum-lithium alloy consisting essentially of, by weight, from about 1.7% up to about 3.5% lithium, from about 0.4% up to about 1.5% oxygen, from about 0.2% up to about 1.2% carbon, and the balance essentially aluminum, said dispersoid being present in a small but effective amount for increased strength up to about 8 volume%, and said alloy being in the solution treated, age hardened condition.
A dispersion strengthened mechanically alloyed aluminum-lithium alloy consisting essentially of, by weight, from about 1.7% up to about 3.5% lithium, from about 0.4% up to about 1.5% oxygen, from about 0.2% up to about 1.2% carbon, and the balance essentially aluminum, said dispersoid being present in a small but effective amount for increased strength up to about 8 volume %, and said alloy being in the solution treated, age hardened condition and having a grain size of the order of 0.1 .mu.m.
A dispersion strengthened mechanically alloyed aluminum-lithium alloy consisting essentially of, by weight, from about 1.7% up to about 3.5% lithium, from about 0.4% up to about 1.5% oxygen, from about 0.2% up to about 1.2% carbon, and the balance essentially aluminum, with the proviso that the oxygen content is sufficient to provide enough dispersoid for the desired level of strength without being so high as to reduce the lithium content in solution below the solubility limit, said dispersoid being present in a small but effective amount for increased strength up to about 8 volume %, and said alloy being in the solution treated, age hardened condition.
Dependencies are inferred from the claim text.