Effects of SiC on the Strengthening Activated Tungsten Inert Gas (SA-TIG) Welded of Magnesium Alloyn^Jun ShenCollege of Material Science and Engineering, Chongqing University, Chongqing, ChinaMshenjun@cqu.edu.cnn^Sizeng LiCollege of Material Science and Engineering, Chongqing University, Chongqing, Chinan^Dajun ZhaiCollege of Material Science and Engineering, Chongqing University, Chongqing, China

摘要

The effects of SiC particles on the morphologies, microstructures, and mechanical properties of tungsten inert gas welded AZ31 magnesium alloy joints with TiO_2 flux coating were studied. The results showed that an increase in the amount of the Ti_2 coating improved the weld penetration and the depth/width (D/W) ratio of the TIG welded AZ31 magnesium alloy seams. The a-Mg grains of FZ of welded joints refined gradually with the addition of micro-sized SiC (<30%) ano-sized SiC (<40%) particles in coatings, and then coarsened when more SiC particles added. In addition, the microhardness of the FZ and ultimate tensile strength of the welded joints increased with the addition of SiC particles, and nano-sized particles have more strong efficiency on the improvement of mechanical properties compared with micro-sized SiC particles.