Room temperature mechanical properties and high temperature oxidation resistance of a high Cr containing Nb-Si based alloy

A high Cr containing Nb-Si based alloy (Nb-12Si-24Ti-10Cr-2Al-2Hf) was prepared by non-equilibrium rapid directional solidification, and then was heat treated at 1400 °C for 10 h. The microstructure was greatly improved by these processes. Big block-like Nb5Si3 was avoided and vermicular one as a strengthening phase uniformly distributed in the toughening NbSS matrix. Exciting fracture toughness (17.9 MPa m1/2) and tensile strength (771 MPa) were achieved for this high Cr containing Nb-Si based alloy. Oxidation behaviors of this alloy at 1200 °C and 1250 °C were also studied.