Microstructure,thermal properties,and corrosion behaviors of FeSiBAlNi alloy fabricated by mechanical alloying and spark plasma sintering

An equiatomic FeSiBAlNi amorphous high-entropy alloy (HEA) was fabricated by mechanical alloying (MA). A fully amorphous phase was obtained in the FeSiBAlNi HEA after 240 h of MA. The bulk FeSiBAlNi samples were sintered by spark plasma sintering (SPS) at 520 and 1080°C under a pressure of 80 MPa. The sample sintered at 520°C exhibited an amorphous composite structure comprising solid-solution phases (body-centered cubic (bcc) and face-centered cubic (fcc) phases). When the as-milled amorphous HEA was consoli-dated at 1080°C, another fcc phase appeared and the amorphous phase disappeared. The sample sintered by SPS at 1080°C exhibited a slightly higher melting temperature compared with those of the as-milled alloy and the bulk sample sintered at 520°C. The corrosion behav-iors of the as-sintered samples were investigated by potentiodynamic polarization measurements and immersion tests in seawater solution. The results showed that the HEA obtained by SPS at 1080°C exhibited better corrosion resistance than that obtained by SPS at 520°C.