Morphology evolution mechanism of single tracks of FeAl intermetallics in selective laser melting

Single tracks of selective laser melted FeAl intermetallics were studied in this paper in order to manufacture a perfect part. The morphology evolution of single tracks with the variation in laser scanning speed was analysed, and the bottom heating of substrate or premelted layer was proposed to obtain a better flattening degree of molten FeAl droplets. Reasonable mechanisms for morphology evolution were provided. It is revealed that with increasing the laser scanning speed, the surface tension gradient plays an important role in morphology evolution, while the bottom heating of substrate or premelted layer can counteract the contraction effect of FeAl particles induced by laser scanning speed.