Research on Hot Deformation Behavior of Mo‐Containing Ti2AlNb‐Based Alloy

Abstract

Herein, the hot compression deformation behavior and microstructure instability of the different Mo‐containing Ti2AlNb‐based alloys are investigated in the temperature range of 900−1150 °C and strain rate range of 0.001−1 s−1. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) are used to characterize the microstructure evolution during the deformation process. The results reveal that Mo element addition can refine the lamellar α2/O phase of Ti2AlNb‐based alloy. In addition, it has a certain influence on the phase‐transition temperature of the alloy, which leads to the narrowing of the O + B2 + α2 phase region. During the hot compression process, the spheroidization of the lamellar structure in Ti2AlNb−0.5Mo alloy is mainly through the transformation of O→B2 + α2, whereas the microstructure of Ti2AlNb−2Mo alloy is mainly converted from the O phase to the B2 phase. In addition, it is found that the high content of Mo element causes the segregation of Al element and leads to poor plasticity and stability of the Ti2AlNb−2Mo alloy. As such, the hot deformation performance of the Ti2AlNb−0.5Mo alloy is significantly better, which provides theoretical guidance for the composition design of the Ti2AlNb‐based alloy.