High-density and low-interstitial Ti-23Al-17Nb prepared by vacuum pressureless sintering from blended elemental powders

Abstract

High-quality Ti2AlNb alloys were prepared from blended elemental powders via cold isostatic pressing and pressureless vacuum sintering. When sintered at 1200 °C, the Ti-23Al-17Nb alloy attained a very high relative density (98.7%) and low contents of interstitials (0.1 wt% O, 0.03 wt% N and 0.005 wt% H). Three crystalline phases – B2, α2, and orthorhombic (O) – were observed in a fine and homogeneous microstructure in the sintered samples. The fine microstructure and low interstitials account for the good mechanical properties achieved: approximately 941 MPa of ultimate tensile strength, 862 MPa of yield strength and 11.7% of elongation.