CoNiFeNb 0.45 Eutectic Medium Entropy Alloy with Excellent Mechanical Properties and Corrosion Resistance

Abstract

A novel CoNiFeNb_0.45 eutectic medium entropy alloy (EMEA) with a dual phase structure is designed and synthesized by arc melting and suction casting. The compression strength of the CoNiFeNb_0.45 EMEA is 2.5 GPa and three times larger than the tensile strength of 790 MPa at room temperature and the tensile strength is maintained at 700 °C. The alloy also has excellent corrosion resistance in the 3.5 wt% NaCl solution at room temperature as manifested by a corrosion rate of merely 0.003 mm/y and the activation energy of corrosion of the CoNiFeNb_0.45 EMEA is 53.6 kJ/mol.