THE EFFECT OF HEAT TREATMENT AND MICROSTRUCTURES ON THE CORROSION PROPERTIES OF ALCOCRFENI HIGH ENTROPY ALLOYS

Abstract

High-entropy alloys have emerged as promising materials in NaCl environment operations due to their superior strength, ductility, and corrosion resistance. This paper investigates the microstructure, mechanical properties, and corrosion behavior of an AlCoCrFeNi HEA alloy after annealing. treatment at 1000 °C and 1200 °C . The alloy was produced via arc melting in an argon environment and underwent 48 hours of annealing in a high-temperature tube furnace to achieve uniform heat distribution. Results showed that higher annealing temperatures led to a greater degree of microstructural refinement and uniformity achieved by the reduced Ni3Al phase fraction as well as enhanced phase stability. The HEA with 1200 °C exhibited exceptional mechanical properties, having an average yield strength of 947 MPa and an average ultimate tensile strength of 1263 MPa, which surpasses Inconel 718 while maintaining considerable levels of ductility. Due to the highly stable Cr2O3 passive film, the 1200 °C annealed HEA was found to outperform SS316 L and 1000 °C HEA in corrosion resistance. The 1200 °C HEA was also observed to provide lower cost than Inconel 718 and lower reliability than SS316L for offshore environments when compared to conventional materials due to better performance in strength-to-corrosion ratio and economic efficiency.