Deformation behavior and microstructure evolution of as-cast Ti2ZrMo0.5Nb0.5 high entropy alloy

A high entropy alloy (HEA) with a composition of Ti2ZrMo0.5Nb0.5 was prepared by vacuum induction melting technology. The mechanical properties at room temperature and elevated temperature (900 degrees C-1150 degrees C), microstructure evolution and hot deformation behavior during hot deformation are studied. The as-cast alloy is composed of equiaxed grains with the yield strength, the apparent plastic strain of 1306 MPa and 44%, respectively. By TEM analysis, the ZrTi2 Laves C15 phase is found corresponding the precipitation strengthening effect accompanied with the solid solution strengthening as a ramification of the high-entropy alloy. Then the hot compression tests were carried out. The deformed alloy still maintains the same single BCC structure as the as-cast state. It is noted that when the temperature is 900 degrees C, the structure of the alloy mainly exhibits dynamic recovery (DRV) characteristics, and when the temperature reaches 1000 degrees C, there are clear dynamic recrystallization (DRX) characteristics in the structure, which are analyzed as the features of continuous dynamic recrystallization (CDRX). Keeping the temperature at 1150 degrees C, when the strain rate is 0.1 s(-1), the characteristics of discontinuous dynamic recrystallization (DDRX) appear, and as the strain rate decreases, CDRX becomes the main recrystallization mechanism again. (C) 2021 The Author(s). Published by Elsevier B.V.

Automated summary

A high entropy alloy (HEA) with a composition of Ti2ZrMo0.5Nb0.5 was prepared and studied for its mechanical properties, microstructure evolution, and hot deformation behavior. It was found that the recrystallization mechanism of the alloy varies with temperature and strain rate during hot compression tests.