EBSD investigation of microstructure and microtexture evolution on additively manufactured TiC-Fe based cermets-Influence of multiple laser scanning.

ABSTRACT

Sustainable TiC-Fe-based cermets have been fabricated by adopting an Additive Manufacturing route based on laser powder bed fusion technology (L-PBF). The objective is to produce crack-free cermet components by employing novel multiple laser scanning techniques with variations in laser process parameters. Electron backscatter diffraction analysis (EBSD) was used to study the microstructure and microtexture evolution with variations in laser process parameters. The investigation revealed that adjusting the preheating scan speed (PHS) and melting scan speed (MS) influenced the growth and nucleation of TiC phases. Lowering these speeds resulted in grain coarsening, while higher scan speeds led to grain refinement with larger sub-grain boundaries. Moreover, a high scanning speed increases the degree of dislocation density and internal stress in the fabricated cermet parts. Notably, it is revealed that decreasing the laser scan speed enhanced the proportion of high-angle grain boundaries in the cermet components, signifying an increase in material ductility.