Effect of hydrogen on the structure of quenched orthorhombic titanium aluminide-based alloy and phase transformations during subsequent heating

Abstract

Abstract-The effect of hydrogen on structure formation and changes in the volume fractions of phases in an alloy based on orthorhombic titanium aluminide (O phase) alloy upon its quenching is studied. X ray diffrac tion analysis is used to determine the lattice parameters of phases. It has been shown that hydrogen is dis solved mainly in the β 0 phase. Differential thermal analysis is used to determine stages and temperature ranges of phase transformations during heating; it was found that introduced hydrogen shifts the β 0 → O and reverse O → β 0 transformations into the low temperature range; the enthalpies of transformation are calcu lated.

Phase Transformations in the Quenched Alloy Based on Orthorhombic Titanium Aluminide during Heating

“…To obtain the necessary set of properties, the O-alloys are heated during thermal and deformation treatments [12,[15][16]. During heating, phase transformations are realized in the O-alloys with the participation of the phases noted above, the staging of which [17][18][19] is largely determined by the phase composition obtained in the alloy before heating, for example, during quenching.…”