Structure and selected properties of Al-Cr-Fe alloys with the presence of structurally complex alloy phases.

The aim of the study was to supplement the data on the AlCrFe alloy with binary phase structure and the AlCrFe alloy with multiphase structure prepared with two different cooling rates from the liquid state. The presence of the structurally complex AlCrFe phase was confirmed by neutron diffraction, scanning electron microscopy with the analysis of chemical composition and transmission electron microscopy. Additionally, the AlCr phase with γ-brass structure was identified for AlCrFe alloy in both cooling rates from the liquid state. Due to the interesting features of structurally complex alloys, the wear resistance, magnetic properties, and corrosion products after performing electrochemical tests were examined. Based on pin-on-disc measurements, a lower friction coefficient was observed for the AlCrFe alloy (µ ≈ 0.55) compared to the AlCrFe multiphase alloy (µ ≈ 0.6). The average hardness of the binary phase AlCrFe alloy (HV = 917 ± 30) was higher compared to the multiphase AlCrFe alloy (HV = 728 ± 34) and the single phase Al-Cr-Fe alloys described in the literature. Moreover, the beneficial effect of rapid solidification on hardness was demonstrated. The alloys AlCrFe and AlCrFe showed paramagnetic behavior, however rapidly solidified AlCrFe alloy indicated an increase of magnetic properties. The studied alloys were characterized by the presence of passive layers after electrochemical tests. A higher amount of oxides on the surface of the AlCrFe alloy was recorded due to the positive effect of chromium on the stabilization of the passive layer.