Structure and mechanical properties of B2 ordered refractory AlNbTiVZrx (x = 0–1.5) high-entropy alloys

Abstract

Structure and mechanical properties of the AlNbTiVZr x (x = 0; 0.1; 0.25; 0.5; 1; 1.5) refractory high-entropy alloys were investigated after arc melting and annealing at 1200°C for 24 h. The AlNbTiV alloy had a B2 ordered single phase structure. Alloying with Zr resulted in (i) change of the degree of order of the B2 phase; and (ii) precipitation of the Zr 5 Al 3 and C14 Laves ZrAlV phases. The density of the AlNbTiVZr x alloys varied from 5590 kg m −3 for the AlNbTiV alloy to 5870 kg m −3 for the AlNbTiVZr 1.5 alloy. The compression yield strength at 22°C increased with an increase in the Zr content from 1000 MPa for the AlNbTiV alloy to 1535 MPa for the AlNbTiVZr 1.5 alloy. The plasticity raised from 6% for the AlNbTiV alloy to > 50% for the AlNbTiVZr 0.5 alloy and then dropped to 0.4% for the AlNbTiVZr 1.5 alloy. At 600°C, the strongest alloy was also the AlNbTiVZr 1.5 , whereas, at 800°C, the AlNbTiVZr 0.1 alloy demonstrated the maximum strength. The plasticity of the AlNbTiV alloy at 600°C increased up to 14.3%, while the Zr-containing alloys had lower plasticity. At 800°C, all the AlNbTiVZr x alloys could be plastically deformed up to 50% of strain without fracture. Ordering in the alloys and the reasons of a complicated dependence of mechanical properties of the AlNbTiVZr x alloys on the Zr content and temperature were discussed.

Effects of Mo, Nb, Ta, Ti, and Zr on Mechanical Properties of Equiatomic Hf-Mo-Nb-Ta-Ti-Zr Alloys

“…There are some researches working on the addition of Al [27,28], Mo [29], Ti [30], V [31], or Zr [32], but few of them focus on the elevated-temperature mechanical performance and the overall effect of the constituent elements. To understand the elemental effect on mechanical properties, equiatomic HfMoNbTaTiZr alloy is firstly designed as a base alloy by adding the high modulus refractory element Mo to HfNbTaTiZr.…”

Enhanced Strength of a Mechanical Alloyed NbMoTaWVTi Refractory High Entropy Alloy

“…will be introduced during the preparing process, which will lead to the formation of precipitated phases [4,8,9]. In fact, several recent studies have revealed that in many cases, dual-phase microstructures can be observed in some HEAs [10,11] and the second phase significantly enhances the strength of HEAs by precipitation strengthening [12,13,14,15,16,17]. Therefore, the precipitated phase, caused by introduction of interstitial elements, may benefit the mechanical properties of HEAs in some cases.…”

Compositional Dependence of Phase Selection in CoCrCu0.1FeMoNi-Based High-Entropy Alloys

“…HEAs are defined as alloys containing at least five major elements wherein every major element has an atomic fraction between 5% and 35% [9]. Various studies on HEAs, including composition, processing, crystal structure and microstructure, and physical and mechanical properties, have been performed in the past years [5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23]. …”