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Indexed by:期刊论文

Date of Publication:2008-12-01

Journal:TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA

Included Journals:SCIE、EI、ISTIC、Scopus

Volume:18

Issue:SPEC. ISSUE 1

Page Number:S96-S100

ISSN No.:1003-6326

Key Words:Mg-Li-Al alloys; electromagnetic stirring (EMS); solution treatment; artificial aging; hardness

Abstract:The effects of external fields such as electromagnetic field on the structure and heat treatment behavior of Mg-Li-Al alloys were studied. Mg-8Li-3Al alloys cast with and without electromagnetic stirring were used for solution treatment and aging treatment. Experimental results show that the dendritic arms are broken and a large quantity of equiaxed grains appear in the microstructure of specimens with electromagnetic stirring (EMS). With the increase of the quenching temperature(150-350 degrees C), the solution of Mg and Al in solid beta phase increases, and the Brinell hardness of the alloy increased as well. Aging peak and over aging happen because theta(MgLi(2)Al) which precipitates in the beta matrix and strengthens the alloy is unstable and transforms to stable AlLi phase. Aging curves of EMS specimens change in a smaller amplitude.