Effect of cyclic oxidation on the tensile behavior of a Fe-Cr-Si coated Nb-base alloy

• DOI: 10.1016/j.corsci.2017.11.023
• Publication Date: 2017-11-24T09:47:50Z
• Authors: Mahesh K. Kumawat; Md. Zafir Alam; Dipak K. Das
• Keywords: Base (topology)

Abstract The room temperature tensile properties of Fe-Cr-Si coated C103 alloy are evaluated after cyclic oxidation at 1100–1300 °C for 30–180 min. The strength increased marginally (by 10–20 MPa) after oxidation at 1100 °C, whereas the ductility decreased by ∼50%. Oxidation at 1300 °C for 180 min caused a greater increase in strength (by 10–15%) and deterioration in ductility to 9%. Localized embrittlement of the substrate sub-surface regions in the vicinity of cracks formed in the coating, HfO 2 precipitation at grain boundaries, and intergranular cleavage caused lowering of ductility during cyclic oxidation. Nevertheless, the coating prevented catastrophic oxidation and is indispensable for hypersonic applications.