Additive manufacturing of a quasicrystal-forming Al95Fe2Cr2Ti1 alloy with remarkable high-temperature strength and ductility

Abstract

Abstract This work investigated the phase formation, thermal stability, and mechanical behavior of a metastable quasicrystal-forming Al95Fe2Cr2Ti1 alloy prepared by selective laser melting (SLM). The powder of this alloy was obtained by gas atomization using recycled material (Al cans) which brings several economic and social advantages. It showed chemical composition, particle size distribution, flowability, and morphology adequate for the SLM process. Samples were produced by SLM in different build directions (0°, 45°, and 90°) with a high relative density of 99.3–99.8%. SLM processing of quasicrystal-forming Al95Fe2Cr2Ti1 powder led to the formation of a microstructure including the presence of nm-sized quasicrystalline precipitates in a dendritic α-Al matrix mainly in the center of the molten pool while the heat-affected zones showed coarser but also nanometric quasicrystalline and crystalline phases. Similar phase formation and hardness of 180.33 HV were observed at the top and bottom of the samples, independent of the build direction. Due to the formation of ultrafine precipitates and refined grains the samples exhibited a high compressive strength at room temperature and 400 °C. The material exhibited a remarkable 140 ± 13 MPa yield strength along with extensive compression ductility at 400 °C, which is higher than what is observed for AlSi SLMed alloys and conventionally processed high-temperature Al alloys. These results show a new opportunity to fabricate higher-performance high-temperature quasicrystal-forming alloys with freedom of geometry design and lower cost.