THE AGEING CHARACTERISTICS OF TERNARY ALUMINIUM-ZINC-MAGNESIUM ALLOYS

Journal Article · Fri Nov 01 04:00:00 EST 1957 · J. Inst. Metals

OSTI ID:4322827

Polmear, I J

A systematic study was made of the aging characteristics of a wide range of ternary aluminum--zinc-magnesium ailoys with basic zinc contents of 4, 6, and 8% zinc and magnesium contents within the range 0 to 3%. Hardness/aging-time curves were determined at regular temperature intervals between --20 and +240 deg C tests being carried out for periods of up to 2 years' duration. The most significant factor in the development of high strength properties in alloys based on the aluminum--zinc --magnesium system appears to be the pronounced effect that small quantities of magnnesium have on the age-hardening capacity of aluminum- zinc alloys. This is thought to arise from the preferential interaction of zinc and magnesium atoms which might be expected from atomic-size considerations and from thermodynamic relationships. The experimental results show clear evidence of the existene of two stages in the aging processes of most of the ternary alloys. Identification of the phases was not possible, but it is concluded that they consist of G.P. zones and an intermediate precipitate. The temperature ranges of stability of the G.P. zones have been established and are shown to extend with increasing degree of supersaturation in respect of both the zinc and magnesium contents. These results will serve as a basin for further studies. (auth)

• Research Organization: Aeronautical Research Labs., Melbourne
• NSA Number: NSA-12-015566
• OSTI ID: 4322827
• Journal Information: J. Inst. Metals, Journal Name: J. Inst. Metals Vol. Vol: 86
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ALUMINUM ALLOYS
ATOMS
DIAGRAMS
HARDNESS
HEAT TREATMENTS
LOW TEMPERATURE
MAGNESIUM ALLOYS
MINERALOGY, METALLURGY, AND CERAMICS
PHASE DIAGRAMS
QUANTITY RATIO
STABILITY
TEMPERATURE
TENSILE PROPERTIES
TESTING
ZINC ALLOYS