Properties and influence of microstructure and crystal defects in Fe2VAl modified by laser surface remelting

Laser surface remelting can be used to manipulate the microstructure of cast materials. Here, we present a detailed analysis of Fe2VAl following laser surface remelting. Within the melt pool, elongated grains grow nearly epitaxially from the heat-affected zone. These grains are separated by low-angle grain bound-aries with 1 degrees-5 degrees misorientations. Segregation of vanadium, carbon, and nitrogen at grain boundaries and dislocations is observed using atom probe tomography. The local electrical resistivity was measured by an in-situ four-point-probe technique. A smaller increase in electrical resistivity is observed at these low angle grain boundaries compared to high-angle grain boundaries in a cast sample. This indicates that grain boundary engineering could potentially be used to manipulate thermoelectric properties. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Automated summary

Laser surface remelting of Fe2VAl results in the growth of elongated grains nearly epitaxially within the melt pool, with low-angle grain boundaries exhibiting segregation of vanadium, carbon, and nitrogen. The study suggests that grain boundary engineering can potentially be used to manipulate thermoelectric properties, as indicated by a smaller increase in electrical resistivity at low-angle grain boundaries compared to high-angle grain boundaries in cast samples.