Microstructure and texture evolution during the manufacturing of in situ TiC-NiCr cermet through selective laser melting process

Abstract

The effects of different selective laser melting (SLM) scan speeds (150 mm.s−1, 95 mm.s−1, 60 mm.s−1, 55 mm.s−1, and 50 mm.s−1) on the microstructure and texture evolution of in situ TiC-NiCr cermet were investigated in the present study. The rotating scan strategy of 60° rotation (Rot-scan) was used to print the samples. Microstructural evolutions were investigated using scanning electron microscopy (SEM). Electron backscatter diffraction (EBSD) and X-ray diffraction analyses were used to identify the micro- and macro-crystallographic preferred orientation (texture). According to the results, the in situ formation of TiC via exothermic reaction resulted in different directions of temperature gradient in the melt pool. Consequently, nucleation and growth occurred in various directions. However, α-fiber texture could be observed in the orientation distribution function (ODF) of the manufactured specimens.