The oxidation-resistant Mo30Si60B10 coating for protection of the T2 phase-based molybdenum alloy

This study focuses on fabrication of a Mo 30 Si 60 B 10 coating with elevated silicon content, which enhances working properties of Mo-alloy based on the Т 2 phase (t-Mo 5 SiB 2 ). The Mo 30 Si 60 B 10 coating has a columnar structure. The alloy is characterized by hardness of 17 GPa; Young's modulus of 304 GPa, and elastic recovery of 29 %. Deposition of the coating increased hardness by 40 %; the Young's modulus, by 18 %; and elastic recovery, by 25 %. Oxidation tests at 1200 °C demonstrated that the specific mass loss of the alloy with Mo 30 Si 60 B 10 coating was 1.5-fold lower than that of the uncoated alloy. An 18 μm thick oxide layer based on a-SiВO and containing MoO 2 particles was formed on the alloy surface. The coating contributes to a ∼14-fold reduction of oxide layer thick. The increase in oxidation resistance of alloy after coating deposition is related to sealing of substrate defects and formation of an a-SiВO layer with elevated silicon content. • An alloy with 96 vol% T 2 phase (t-Mo 5 SiB 2 ) was obtained by SHS and HP methods. • Mo 30 Si 60 B 10 coating increased the mechanical properties of the alloy by 18–40 %. • Coating deposition reduces the thick of the oxide layer by 14 times at 1200 °C. • Improved oxidation resistance of the coating is associated with a high Si content.