Excellent combination of compressive strength and strain of AlCrFeNi MPEAs via adding Ti and V

In the current work, the influences of 12% X (X = Ti, V and Ti+V) on the structure and mechanical properties for AlCrFeNi matrix are compared in parallel. After mixing different component, parent phases (NiAl + Cr-Fe) of (AlCrFeNi)88%X12% multi-principal element alloys (MPEAs) can't result in phases separation. Nevertheless, 12 at% Ti-and V-mixed MPEAs lead to extra strengthening through new precipitating phases of L21 (Ni2TiAl) and BCC (Fe-V). For (AlCrFeNi)88%Ti6%V6%, the two precipitating phases promote the sy-nergistic strengthening of the strength and compressive strain. Ti is more effective than V in enhancing grain boundary energy of matrix, because Ti can induce more negative enthalpy of mixing, which makes the aggregation easier. Following identical mixing content, V causes pronounced solid solution strengthening but does not benefit the grain boundary strengthening, triggering an increase in ultimate strength of AlCrFeNi88%V12%. Significantly, the effectiveness of coordination strengthening is boosted by mixing 6%Ti + 6%V. (AlCrFeNi)88%Ti6%V6% has excellent compressive yield strength and strain, which is 1403.4 MPa and 23.1%, respectively. Our present analysis suggests that strengthening mechanism is applicable to explain the differences in nano interstitial structure, low Ti diffusion and non-equilibrium pinning effect of cooperative reinforcement of BCC (Fe-V) and L21(Ni2TiAl) phases.(c) 2023 Elsevier B.V. All rights reserved.

Automated summary

This study compares the influences of 12% Ti, V, and Ti+V on the structure and mechanical properties of AlCrFeNi matrix. Mixing Ti and V leads to additional strengthening through new precipitating phases, while Ti is more effective than V in enhancing grain boundary energy. V causes solid solution strengthening but does not benefit grain boundary strengthening. The combination of Ti and V enhances the coordination strengthening. The AlCrFeNi alloy with 88% Ti, 6% V, and 6% Ti+V exhibits excellent compressive yield strength and strain.