Hot pack rolling of spark-plasma-sintered pre-alloyed powders to fabricate Ti 2 AlNb sheets

Abstract

In this work, spark-plasma-sintered Ti-20.3Al-24.7Nb (at.-%) compact was pack rolled in different phase fields to fabricate Ti₂AlNb sheets with high strength and ductility without post-heat treatment. The nano O phases in the B2 matrix contributed to the high tensile strength and ductility in a single B2 phase field. In the O + B2 phase field, the O phases remarkably increased in size and resulted in high tensile strength of 1407.1 MPa. Maintaining the O phases to nano sizes and cooperation with micro-sized α₂ phases resulted in extremely high elongation of 13.91% in the α₂+O + B2 phase field. The , , , and strengthening effects of the α₂ and O phases under different conditions were analysed in detail.

Highlights

Spark-plasma-sintered pre-alloyed powders are used as the raw compact before hot pack rolled Ti₂AlNb sheet.

Ti₂AlNb sheets with good mechanical properties are obtained without any post-heat treatment.

This ‘SPS pre-alloyed powder + hot pack rolling’ method has great potential in breaking the limit in sheet properties.

The strengthening effects of different factors are analysed.