Achieving high ductility of Ti2AlNb sheet without sacrificing the tensile strength without post heat treatment

Abstract

So far, one main shortcoming restricting the wide application of Ti2AlNb sheet is the poor ductility. To solve this problem, we hot packed rolled the Ti2AlNb compact prepared by spark-plasma-sintering the pre-alloyed powders at the α2+B2+O phase field in this work. The sheets were rolled by different thickness reductions and passes. Results showed that the packs made of 304 stainless steel effectively protected the Ti2AlNb sheet from cracking, and the obtained sheets had good surface formation quality. B2 grain size and the texture intensity increased with increasing the rolling pass. The sheets rolled by all schemes had excellent ductility and relative high strength without applying any post heat treatment. An extreme high elongation of 13.91% with a tensile strength of 1063.27 MPa was obtained after four rolling passes. The nano O phases had excellent ability to coordinate transformations and account for the excellent ductility of the sheet. The α2 phases mainly strengthen the strength of the sheet; maintaining its high strength. This work may provide a new insight to develop commercial high ductility Ti2AlNb alloys.