Selective Laser Melting of Commercially Pure Silicon

Selective laser melting (SLM) or Laser-based powder bed fusion (LBPF) is gaining much attention for the fabrication of novel materials with complex shapes, improved functionalities, and properties. An attempt has been made to fabricate hard and brittle silicon via SLM in the absence of any cracks. Two different powder batches were used, where one of the powder batches has 0.3wt% Fe and the other batch with 0.02wt% Fe. The parameter optimization process shows that the SLM Si samples were successfully fabricated from the powders with the minor addition of Fe. The deliberate addition of Fe facilitates heterogeneous nucleation of Si and aids in absorbing the laser energy beam more efficiently. SLM Si samples with 98.5% theoretical density were fabricated with a hardness of around 10.65±40 GPa. The experimental results show that SLM can successfully fabricate Si without cracks and with near theoretical density (of 99%) and complex shapes, which opens their use in wider industrial applications.