Scanning and transmission electron microscopy microstructure characterization of mechanically alloyed Nb-Ti-Al alloys.

Results are presented of an investigation of the microstructure development during mechanical alloying and following consolidation of an Nb15Ti15Al alloy. The alloy was synthesized from elemental as well as pre-alloyed powders. The microstructure of this material was examined by transmission electron microscopy, scanning electron microscopy and X-ray diffraction. The use of pre-alloyed TiAl powder for synthesis of the Nb15Ti15Al alloy meant that a much shorter time was required to complete the mechanical alloying process compared with the synthesis of elemental powders. The investigation indicates that three phases were present in the consolidated materials: the Nb solid solution, the Nb(3)Al intermetallic phase and the dispersoid.