Effects of Si addition on properties of Fe–Cr–W–Ti–Y2O3 alloy fabricated by mechanical alloying

Highlights: • Effects of Si addition on the properties of Fe-based alloy had been investigated. • Si addition was beneficial for enhancing the resistance to oxidation of the alloy. • Tensile strength was increased when Si was added. - Abstract: Effects of Si element on characteristics of Fe–Cr–W–Ti–Y2O3 alloy, including relative density, tensile strength, oxidation resistance and microstructure had been investigated. The results showed that the alloy with Si addition appeared superior properties than alloy without Si. The relative density and tensile strength of alloy without Si were only around 85% and 300 MPa, while that of alloy adding Si could reach up to 96.8% and 692.7 MPa after sintering at 1350 °C. Mass gain of alloy adding Si was approximately one tenth that of alloy without Si when oxidized at 650 °C and 850 °C. These superior properties were attributed to action of Si in sintering and oxidation processes. It would activate the sintering for more dense alloy, and form protective oxidized film preventing diffusion of oxygen and metal atoms