Application of thermal modelling to laser beam welding of aluminium alloys

Microstructural characterization and grain refinement of AA6082 gas tungsten arc welds by scandium modified fillers

“…The decrease in grain size is observed to be marginal up to 0.5% Sc, where as further addition of Sc has resulted in grater refinement of grain size. These observations are consistent with the observations made by Norman et al [32] during MIG welding of 7000 series alloys using AleSc fillers. The minimum level of Sc required to achieve grain refinement, therefore, depends on the presence of the L þ Al 3 Sc phase field, which in turn depends on the alloy composition [22].…”

Effects of Sc and Zr on mechanical property and microstructure of tungsten inert gas and friction stir welded aerospace high strength Al–Zn–Mg alloys

“…TIG welding was performed manually on Fronius welding machine parallel to the rolling direction of the alloy plates, using 3 mm newly developed Al-6.0Mg-0.25Sc-0.10Zr (wt%) welding wires, which can effectively reduce the risk for solidification hot cracking and improve the tensile property of fusion zone compared with conditional commercial filler materials, such as ER 5556, ER5183, ER5356, 5087, 5180 and 5093 [14]. Before TIG welding, the alloy plates were subjected to surface treatment.…”

“…4(b), are observed at fusion boundary and in HAZ, but they are hardly found in fusion zone in Al-Zn-Mg-Sc-Zr alloy weld joint. Norman [14] indicates that a critical minimum concentration of $0.4 wt% Sc in fusion zone is required to form primary Al 3 Sc x Zr 1 À x particles and produces grain refinement even in the presence of 0.15 wt% Zr. This behavior mirrors that previously reported in binary Al-Sc alloys where the transition in grain size is more pronounced, but occurs at a higher Sc concentration of 0.55 wt% [9].…”

“…Tungsten inert gas welding process is the most widely used welding technology for aerospace aluminum alloys [13,14]. However, until the past decade the aerospace industry has not seriously considered fusion welding high strength 7000 series aluminum alloys, as an alternative to mechanical fastening, because such alloys have generally been regarded as unweldable.…”

“…However, until the past decade the aerospace industry has not seriously considered fusion welding high strength 7000 series aluminum alloys, as an alternative to mechanical fastening, because such alloys have generally been regarded as unweldable. Norman [14,15] and Sundaresan [16] Contents lists available at ScienceDirect developed new aluminum filler wires added with scandium which can improve the quality of solidification structure produced in fusion zone, reduce weld solidification cracking susceptibility, enhance the weldability and mechanical property of fusion welded joint, thereby those filler materials can be used to produce welds in aerospace 7000 series Al alloys with property levels that are acceptable for many aerospace applications. Currently, existing literature basically focuses on the effects of Sc additions into filler materials on welding performance and the relationship between the property and microstructure of TIG welded joints.…”