Superplastic behavior of Al-coated Mg alloy sheet

JOURNAL OF ALLOYS AND COMPOUNDS

卷:601

Article

Tokunaga, Toko^1,2  Matsuura, Kiyotaka³  Ohno, Munekazu³ 

[1] Japan Soc Promot Sci, Kita Ku, Sapporo, Hokkaido 0608628, Japan

[2] Hokkaido Univ, Grad Sch Engn, Kita Ku, Sapporo, Hokkaido 0608628, Japan

[3] Hokkaido Univ, Fac Engn, Kita Ku, Sapporo, Hokkaido 0608628, Japan

关键词: Mg alloy;    Composite material;    Cladding;    Superplasticity;    Mechanical property;   

DOI  :  10.1016/j.jallcom.2014.02.099

来源: Elsevier

【 摘 要 】

An Al-coated Mg alloy sheet is fabricated by hot forging an Al-coated Mg alloy plate produced by hot extrusion of a Mg alloy billet together with an Al plate. The sheet consists of recrystallized fine grains both in the Mg alloy substrate and Al coating layer. A thin intermetallic compound layer of Al3Mg2 formed at the Al/Mg interface in the hot-extruded plate. The subsequent hot forging reduces the thickness of the intermetallic layer but induces cracks in the intermetallic compound. This sheet exhibits a large tensile elongation of 550% at 573 K and at a strain rate of 1.0 x 10 (3)s (1). Notably, a tensile test of an Al specimen exhibited only 40% elongation, while that of a Mg alloy specimen exhibited 800% elongation. It is suggested that the large elongation of Al as the coating layer on the Mg alloy is attributable to the good bonding of the Al coating layer and the Mg alloy substrate. The cracks in the intermetallic layer disappear during the tensile tests at elevated temperatures and no cracks are observed in the elongated specimens, which indicates growth of the intermetallic and reparation of the cracks occurred during the low strain-rate hot deformation of the Al-coated Mg alloy sheet. (C) 2014 Elsevier B.V. All rights reserved.

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