Enhancing mechanical performance of Ti2ZrNbHfVAlx refractory high-entropy alloys through laves phase

Refractory high-entropy alloys (RHEAs) have attracted significant interest because of their exceptional mechanical characteristics. This study examines the mechanical characteristics, microstructure and strengthening mechanism of Ti2ZrNbHfVAlx alloys (x = 0, 0.2, 0.4, 0.6, 0.8, 1, and 1.2). The results demonstrate that the introduction of Al causes a transformation in the phase structure of the alloys, resulting in the BCC phase and the Laves phase, characterized by a distinctive dendritic microstructure. The compressive yield strength is positively correlated with the rising Al content, while also resulting in a noticeable decrease in ductility due to the presence of the Laves phase. One of the alloys, the compressive yield strength of Ti(2)ZrNbHfVAl1.2 RHEA is as high as 1789.94 MPa, the compressive strain is 10.60 %, and the specific yield strength (SYS) of 269.67 kPa m3 kg(-1). Moreover, the Vickers hardness exhibits a rise from 317.29 to 533.73 HV. The high compressive yield strength mostly originates from solid solution and the second phase strengthening. The current investigation not only offers a resolution for attaining a harmonious combination of strength and ductility but also gives a valuable understanding of the advancement of RHEAs with exceptional mechanical characteristics.