Non-isothermal oxidation kinetics of FeSiAl alloy powder for microwave absorption at high temperature

Exploring efficient microwave absorbers at high temperature is a hot topic in the practical application. Non-isothermal oxidation kinetics of FeSiAl alloy powder sized of ∼45 μm were investigated by thermogravimetry analysis (TG) and differential scanning calorimetry (DSC) under linear temperature control program (ranging from 30 to 1200 °C) at different heating rates (5, 10, 15, 20 and 25 K/min) in air. It can be found that the melt point of FeSiAl alloy powder is about 1165 °C. The oxidation of FeSiAl alloy powder can be divided into two stages including solid-oxidation stage (before melting) and liquid oxidation stage (after melting). Non-isothermal kinetic analysis of oxidation of FeSiAl alloy powder were performed by using Flynn-Wall-Ozawa (FWO) method. Besides, the surface morphology of particles present a smooth trend by scanning electron microscope. And the microwave absorption performance of FeSiAl alloy powder is confirmed to be a good potential candidate in case of high temperature with the lowest refection loss value of −25.14 dB and effective absorbing bandwidth in range of 4-18 GHz adjusting the thickness.