THE MECHANICAL PROPERTIES OF ALUMINIUM-LITHIUM ALLOYS

Journal Article · Wed Jun 01 00:00:00 EDT 1960 · J. Inst. Metals

OSTI ID:4168381

Jones, W R.D.; Das, P P

The mechanical properties of aluminum-lithium alloys made from high- purity materials were determined. The best combination of properties in the binary system is gifen by alloys with a lithium content of approximately 2 to 2.5%, after solution-treatment at 580 deg C and aging at 130 deg C. The alloys are capable of age-hardening; the strength is in- creased, but the ductility is decreased, and this has restricted their use. A third metal (zinc, magnesium, tin, or copper) was added to the 2% lithium alloy in an attempt not only to increase its strength without sacrificing too much ductility, but also to increase the proof stress so that high ductility values may not be of prifuary importance. Preliminary tests showed that additions of zinc and of tin did not result in any substantial improvement. Additions of magnesium and of copper are beneficial after certain treatments; approximately 1% magnesium or copper prcduces sheets which, in the hot-rolled, solution-treated, and aged condition, have a proof stress, tensile strength, and elongation of 11 tons,/in./sup 2/, 17 tons/in./sup 2/, and 14%, respectively, thus giving a value of approximately 7 for the strength: weight ratio. Higher strengths can be attained, but only at the expense of ductility; e.g. when the magnesium content was increased to approximately 1.75%, sheets cold rolled and subsequently aged had a strength of 28 tons/in./sup 2/ with an elongation of only 6.5%, and with approximately 2.25% copper the corresponding values were 32 and 5. Although these figures are not promising for commercial purposes, the alloys have an advantage in that the proof stress is high and that it is possible to obtain a value of approximately 12 for the strength: weight ratio. (auth)

• Research Organization: University Coll., Cardiff, Eng.
• NSA Number: NSA-14-022060
• OSTI ID: 4168381
• Journal Information: J. Inst. Metals, Vol. Vol: 88; Other Information: Orig. Receipt Date: 31-DEC-60
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

METALS, CERAMICS, AND OTHER MATERIALS
ADDITIVES
ALUMINUM ALLOYS
CHEMICALS
COPPER
DUCTILITY
EFFICIENCY
ELEMENTS
HEAT TREATMENTS
HOT WORKING
IMPURITIES
LITHIUM ALLOYS
MAGNESIUM
MATERIALS TESTING
MECHANICAL PROPERTIES
QUANTITATIVE ANALYSIS
ROLLING
SHEETS
STRESSES
TEMPERATURE
TEMPERING
TENSILE PROPERTIES
TIN
WEIGHT
ZINC-