Effects of welding current on properties of A-TIG welded AZ31 magnesium alloy joints with TiO2coating
- Resource Type
- Article
- Authors
- SHEN, Jun; ZHAI, Da-jun; LIU, Kai; CAO, Zhong-ming
- Source
- Transactions of Nonferrous Metals Society of China; August 2014, Vol. 24 Issue: 8 p2507-2515, 9p
- Subject
- Language
- ISSN
- 10036326
The effects of welding current on the macro-morphology, microstructure and mechanical properties of tungsten inert gas (TIG) welded AZ31 magnesium alloy joints with TiO2coating were investigated. The results showed that the increase of welding current led to the increase in the depth/width ratio and deteriorated the surface appearance of the welded seams with TiO2coating. The grain size of α-Mg and the amount of granular β-Mg17Al12particles in the welded seams also increased. The welded joints with TiO2coating exhibited a deeper weld penetration and larger grain size compared with the welded joint without TiO2coating. When the welding current was less than 130 A, the ultimate tensile strength of the welded joints with TiO2coating increased with the increase in welding current and then decreased when the welding current was greater than 130 A. The average microhardness of the heat-affected zone and fusion zone decreased gradually with the increase of welding current.