Improvement in the oxidation resistance of Nb-Si based alloy by selective laser melting

Nb-18Si-24Ti-2Cr-2Al-2Hf (at.%) alloy was fabricated by selective laser melting (SLM). Results showed that an ultra-fined microstructure was achieved by SLM. After oxidation at 1250 °C for 50 h, the weight gains of Nb-Si based alloys via SLM and vacuum induction melting (VIM) were 96.48 mg/cm2 and 198.91 mg/cm2, respectively. Compared with the VIM alloy, the SLM alloy exhibited a slower oxidation kinetic rate, featured by the formation of a more compact oxide scale without spallation. The improvement in the oxidation resistance was attributed to the microstructure refinement.