Characterisation of Additively Produced SS316L
摘要
Microstructural characterisation and mechanical property evaluation of additively manufactured SS316L was performed in order to establish microstructure property correlations in it. Detailed microstructural evaluation of the laser powder bed fused part revealed the presence of layered structure of solidified melt pools on the transverse plane and long columnar grains on the built plane. At higher magnification, fine elongated shaped grains were also observed inside those grains, which were seen to be growing from the melt pool boundaries. The parts were free from gross defects such as macro-voids and lack of fusion. However, few pores, spherical particles (inclusion) and micro-cracks were also seen to be present inside the material. Results of the chemical analysis across the spherical particles and micro-cracks revealed the presence of Mn, Si, Al and O in them. Tensile tests of the processed specimens revealed higher values of strength with slight reduction in ductility as compared to conventionally processed part. Fractography results showed cup and cone type of fracture with dimples on their surfaces. Interestingly, a few elongated voids were also seen in the fractographs, which indicated their initiation from the defects like micro-cracks and pores.