Mechanical and fracture behavior of powder metallurgy processed Ti3Al-based alloys

This work considers structural and compression mechanical properties of three Ti3Al-based alloys processed by powder metallurgy. Mechanically alloyed powders were compacted by hot-pressing to non-porous homogenous compacts. Prior to compression tests, all compacts were homogenized by a solution treatment at 1050 degrees C (alpha + beta region) for 1h, followed by water quenching. The compression tests were performed from room temperature to 500 degrees C in vacuum at a strain rate of 2.4 x 10(-3) s(-1). Detailed microstructural characterization has been evaluated by scanning electron microscopy (SEM), followed by electron dispersive spectroscopy (EDS) and X-ray diffraction analysis. Fracture topography was examined by SEM. The Ti3Al-Nb alloy exhibits the highest ductility in the whole temperature range, whereas addition of Mo to Ti3Al-Nb alloy yields the highest ultimate compression strength. A correlation between ductility and the fracture mode exists for all materials. (c) 2006 Springer Science + Business Media, Inc