Microstructure, phase formation and properties of rapid solidified Al–Fe–Cr–Ti alloys

Improvements in the mechanical strength of Al–Fe–Cr–Ti alloys have been demonstrated when non-equilibrium microstructures are developed. This paper investigated the effect of cooling rate and composition on the phase formation, microstructure and properties of new Al 96.6 Fe 1.5 Cr 1.7 Ti 0.2 and Al 91.6 Fe 4.9 Cr 2.2 Ti 1.3 (at.-%) alloys. Wedge-shaped samples produced by suction casting were characterised by optical, scanning electron microscopy, differential scanning calorimetry, X-ray diffraction, energy dispersive X-ray spectroscopy and microhardness. The results showed that the morphology and size of the phases precedent of the flower-like phases change from small, spherical particles to large flower-like phases with decreasing the cooling rate. The presence of intermetallic phases Al 13 Fe 4 , Al 13 Cr 2 and Al 3 Ti in the Al 91.6 Fe 4.9 Cr 2.2 Ti 1.3 alloy, resulted in a hardness 1.6 times higher compared to the Al 96.6 Fe 1.5 Cr 1.7 Ti 0.2 alloy.