Use of inoculants to refine weld solidification structure and improve weldability in type 2090 AlLi alloy

The refinement of weld solidification structures will be useful not only because it is known to reduce the tendency to hot cracking, but also because the mechanical properties of the fusion zone are likely to be improved. In the current work, welds were produced in a type 2090 AlLi alloy using two filler materials based on types 2319 and 4043. Grain refinement was induced in the weld fusion zones through inoculation with Ti, Ti+B and Zr. Microstructural characterization showed that all three reduced grain size considerably, with Zr being the most effective. The structural refinement was found to reduce hot cracking susceptibility (measured by Varestraint testing), enhance post-weld age-hardening response and also improve tensile properties, especially ductility. The results showed that in the peak-aged condition the tensile elongations in the inoculated welds equalled or exceeded that in the base material.