Metallurgy of Iron and Nickel Alloys Welded with Power Beam Processes

The laser and electron power beam processes enable deep penetration and high travel speed welds. The resultant solidification rates can be significantly higher than the traditional arc processes and may lead to unexpected discontinuities and microstructures. Investigating these differences is crucial to furthering both a fundamental understanding and applied engineering of power beam process metallurgy. The current work investigated power beam welding of dissimilar iron and nickel alloy pairs. In these pairings the nucleation and growth of the weld metal at the fusion boundaries was of particular interest. Changes in phase and morphology with change in weld composition were investigated and characterized with optical microscopy, electron backscatter diffraction, and microhardness maps.