Microstructures and Mechanical Properties of Tungsten Inert Gas Welded Magnesium Alloy AZ91D Joints
Microstructures and Mechanical Properties of Tungsten Inert Gas Welded Magnesium Alloy AZ91D Joints
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钨极惰性气体保护焊镁合金AZ91D接头的显微组织和力学性能
DOI：
10.2355/isijinternational.46.1200
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发表时间：
2006
影响因子：
1.8
通讯作者：
J. Li
中科院分区：
文献类型：
--
作者：
Daqian Sun;D. Sun;S. Yin;J. Li
研究了焊缝成分和热输入对钨惰性气体（TIG）焊接镁合金AZ91D接头组织和力学性能的影响。当镁合金焊缝Al含量从6.9 wt%增加到9.8 wt%时，焊缝金属中脆性Al12Mg17相的面积分数从6.2 wt%增加到7.3%，焊缝金属的强度和伸长率从215 MPa和7.9%下降到192 MPa和4.9%。当热输入从73.6 kJ增加到147.2 kJ时，焊缝金属的晶粒变粗，部分熔化区宽度从120 μm增加到210 μm。与母材AZ91D相比，焊接接头的力学性能较差。接头的强度和伸长率分别约为母材强度（156 MPa）和伸长率（4.8%）的70%和73%。节理断裂主要发生在晶界Al12Mg17相较宽的PMZ。
Effects of weld composition and heat input on microstructures and mechanical properties of tungsten inert gas (TIG) welded magnesium alloy AZ91D joints have been investigated. Increasing magnesium alloy weld Al contents from 6.9 to 9.8 wt%, the area fraction of brittle Al12Mg17 phases in the weld metals increased from 6.2 to 7.3% and the strength and elongation of the weld metals decreased from 215 MPa and 7.9% to 192 MPa and 4.9%. Increasing the heat inputs from 73.6 to 147.2 kJ resulted in the grain coarsening of the weld metals and the partially melted zone (PMZ) width increasing from 120 to 210 μm. The mechanical properties of welded joints are poor compared with those of the base metal AZ91D. The strength and elongation of the joints are about 70% and 73% of the strength (156 MPa) and elongation (4.8%) of the base metal, respectively. The joint fractures mainly occurred in the PMZ with broader Al12Mg17 phases at the grain boundaries.