Hot deformation of ultrafine-grained TiC-reinforced AlCrFeNbMoTiV refractory high entropy alloys

Abstract. In the present work, the hot deformation behavior of the AlCr0.2FeNbMoTiV2 refractory high-entropy alloy was studied by means of its constitutive modeling. The samples were fabricated using mechanical alloying and spark plasma sintering, resulting in an ultrafine-grained microstructure consisting of a main bcc solid solution, Laves phase, and TiC and Al2O3 precipitates. Compression tests between 950 and 1100 ºC and 5·10-4 and 10-2 s-1 of strain rate were performed in order to determine the constitutive equations. Additionally, the samples were subjected to a heat treatment at 1350 ºC for 16 h, presenting a considerable increment in the specific yield strength (from 33 to 94 MPa·g-1·cm3 at 1000 ºC) accompanied by a slight increase of the grain size (from 0.35 to 1.2 µm). Overall, the heat-treated AlCr0.2FeNbMoTiV2 alloy presented one of the highest specific yield strength values among refractory high entropy alloys.