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

• Published in: Corrosion science Vol. 127; pp. 260 - 269
• Main Authors: Guo, Yueling, Jia, Lina, Kong, Bin, Zhang, Fengxiang, Liu, Jinhui, Zhang, Hu
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Ltd 01.10.2017; Elsevier BV
• Subjects: Alloys; Induction melting; Intermetallics; Laser beam melting; Melting; Microstructure; Nb-Si alloy; Niobium base alloys; Oxidation; Oxidation resistance; Rapid solidification; Scale (corrosion); Selective laser melting; Spallation; Vacuum induction melting; Intermetallics; Oxidation; Selective laser melting; Rapid solidification; Nb-Si alloy
• ISSN: 0010-938X; 1879-0496
• DOI: 10.1016/j.corsci.2017.08.022

•Weight gain of oxidised Nb-Si alloys was reduced by selective laser melting.•A more compact oxide scale was grown on selective laser melted alloy.•Microstructure refinement promoted the formation of a continuous SiO2 layer.•Microstructure refinement improved the oxidation resistance of Nb-Si alloys. 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 50h, the weight gains of Nb-Si based alloys via SLM and vacuum induction melting (VIM) were 96.48mg/cm2 and 198.91mg/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.