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 be cause 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. Micro structural characterization showed that all three reduced grain size consid erably, with Zr being the most effective. The structural refinement was fou nd to reduce hot cracking susceptibility (measured by Varestraint testing), enhance post-weld age-hardening response and also improve tensile properti es, especially ductility. The results showed that in the peak-aged conditio n the tensile elongations in the inoculated welds equalled or exceeded that in the base material. (C) 2000 Elsevier Science S.A. All rights reserved.