Microstructures and electrothermal properties of AlxCrFeNi multi-component alloys

AlxCrFeNi multi-component alloys were fabricated by vacuum arc-melting to study the effect of homogenization on microstructures of as-cast and homogenized alloys using X-ray diffraction, scanning electron microscopy and transmission electron microscopy. Besides, electrical resistivity and thermal conductivity of as-cast and homogenized alloys were also investigated. The results showed that no obvious differences of crystal structures and phase compositions between these as-cast and homogenizing alloys were presented. However, transmission electron microscope indicated that the ordered B2 NiAl intermetallic nanoparticles, which were distributed on the disordered BCC [Fe, Cr] solid solution of as-cast Al1.2CrFeNi alloy, disappeared after homogenization. For AlxCrFeNi alloys, the electrical resistivity increased with Al addition and dramatic increase of thermal conductivity was presented with increasing the homogenization temperatures. However, homogenization could decrease both electrical resistivity and thermal conductivity of as-cast alloys. The main factors influencing the changes of electrothermal properties of AlxCrFeNi alloys were the electron scattering affected by crystal defects, phase boundaries and temperatures.