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Title: Characterization of AZ31B wrought magnesium alloy joints welded by high power fiber laser

Abstract

A 6 kW fiber laser is used to weld AZ31B wrought magnesium alloy and the characterization of welded joints are studied by the observations of bead size, microstructure and mechanical properties. The accepted joints without macro-defects can be obtained when the laser power is in the range of 2.5 to 4.0 kW. Typical hexagonal dendrites are observed in the fusion zone, whose average semi-axis length increases with increasing heat input or decreasing welding speed. The minimum ultimate tensile strength of welded joints reaches 227 MPa, 94.6% of the base metal. And when the heat input reduces to 48 J/mm or lower, the joints are fractured in the base metal, showing stronger failure strength compared to the base metal. For the joints ruptured in the weld metal, the fracture surface is characterized by a ductile-brittle mixed pattern consisting of both dimples and cleavages. Finally, the formation mechanism of pore in the welds is discussed and summarized by the pore morphologies on the fracture surface. - Highlights: {yields} Accepted joints of AZ31B Mg alloy are produced by high power fiber laser. {yields} Optimal welding parameters are summarized by experimental observations. {yields} Obvious hexagonal dendrites are observed in the fusion zone. {yields} Themore » joints are stronger than base metal as the heat input is lower than 48 J/mm. {yields} Pore formation mechanism of welded joints is discussed and summarized.« less

Authors:
; ;
Publication Date:
OSTI Identifier:
22066335
Resource Type:
Journal Article
Journal Name:
Materials Characterization
Additional Journal Information:
Journal Volume: 62; Journal Issue: 10; Other Information: Copyright (c) 2011 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1044-5803
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; CLEAVAGE; DENDRITES; FRACTURES; HEXAGONAL LATTICES; LASER WELDING; MAGNESIUM ALLOY-AZ31B; MORPHOLOGY; SURFACES; TENSILE PROPERTIES; WELDED JOINTS

Citation Formats

Zemin, Wang, Gao Ming, E-mail: mgao@mail.hust.edu.cn, Haiguo, Tang, and Xiaoyan, Zeng. Characterization of AZ31B wrought magnesium alloy joints welded by high power fiber laser. United States: N. p., 2011. Web. doi:10.1016/J.MATCHAR.2011.07.002.
Zemin, Wang, Gao Ming, E-mail: mgao@mail.hust.edu.cn, Haiguo, Tang, & Xiaoyan, Zeng. Characterization of AZ31B wrought magnesium alloy joints welded by high power fiber laser. United States. doi:10.1016/J.MATCHAR.2011.07.002.
Zemin, Wang, Gao Ming, E-mail: mgao@mail.hust.edu.cn, Haiguo, Tang, and Xiaoyan, Zeng. Sat . "Characterization of AZ31B wrought magnesium alloy joints welded by high power fiber laser". United States. doi:10.1016/J.MATCHAR.2011.07.002.
@article{osti_22066335,
title = {Characterization of AZ31B wrought magnesium alloy joints welded by high power fiber laser},
author = {Zemin, Wang and Gao Ming, E-mail: mgao@mail.hust.edu.cn and Haiguo, Tang and Xiaoyan, Zeng},
abstractNote = {A 6 kW fiber laser is used to weld AZ31B wrought magnesium alloy and the characterization of welded joints are studied by the observations of bead size, microstructure and mechanical properties. The accepted joints without macro-defects can be obtained when the laser power is in the range of 2.5 to 4.0 kW. Typical hexagonal dendrites are observed in the fusion zone, whose average semi-axis length increases with increasing heat input or decreasing welding speed. The minimum ultimate tensile strength of welded joints reaches 227 MPa, 94.6% of the base metal. And when the heat input reduces to 48 J/mm or lower, the joints are fractured in the base metal, showing stronger failure strength compared to the base metal. For the joints ruptured in the weld metal, the fracture surface is characterized by a ductile-brittle mixed pattern consisting of both dimples and cleavages. Finally, the formation mechanism of pore in the welds is discussed and summarized by the pore morphologies on the fracture surface. - Highlights: {yields} Accepted joints of AZ31B Mg alloy are produced by high power fiber laser. {yields} Optimal welding parameters are summarized by experimental observations. {yields} Obvious hexagonal dendrites are observed in the fusion zone. {yields} The joints are stronger than base metal as the heat input is lower than 48 J/mm. {yields} Pore formation mechanism of welded joints is discussed and summarized.},
doi = {10.1016/J.MATCHAR.2011.07.002},
journal = {Materials Characterization},
issn = {1044-5803},
number = 10,
volume = 62,
place = {United States},
year = {2011},
month = {10}
}