Abnormal distribution of microhardness in tungsten inert gas arc butt-welded AZ61 magnesium alloy plates

Journal Article · Thu Jul 15 00:00:00 EDT 2010 · Materials Characterization

DOI:https://doi.org/10.1016/J.MATCHAR.2010.04.003· OSTI ID:22066260

Nan, Xu ^[1]; Weidong, Xie; Linzhi, Wang; Dan, Wang; Dong, Min ^[1]

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1. College of Material Science and Engineering, Chongqing University, Chongqing 400044 (China)

In this study, the effects of heat input on the distribution of microhardness of tungsten inert gas (TIG) arc welded hot-extruded AZ61 magnesium alloy joints were investigated. The results show that with an increase of heat input, the distributions of microhardness at the top and bottom of the welded joints are different because they are determined by both the effect of grain coarsening and the effect of dispersion strengthening. With an increase of the heat input, the microhardness of the heat-affected zone (HAZ) at the top and bottom of welded joints and the fusion zone (FZ) at the bottom of welded joints decreased gradually, while the microhardness of the FZ at the top of welded joints decreased initially and then increased sharply. The reason for the abnormal distribution of microhardness of the FZ at the top of the welded joints is that this area is close to the heat source during welding and then large numbers of hard {beta}-Mg{sub 17}(Al,Zn){sub 12} particles are precipitated. Hence, in this case, the effect of dispersion strengthening dominated the microhardness.

• OSTI ID: 22066260
• Journal Information: Materials Characterization, Vol. 61, Issue 7; Other Information: Copyright (c) 2010 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 1044-5803
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
HEAT AFFECTED ZONE
MAGNESIUM BASE ALLOYS
MICROHARDNESS
MICROSTRUCTURE
PARTICLES
PLATES
TUNGSTEN
WELDED JOINTS
WELDING
ZINC ALLOYS