Structural and mechanical evaluation of the effect of oxygen boost diffusion on a gamma titanium aluminide of Ti–45Al–2Nb–2Mn–1B

Air oxidation, vacuum heating and a subsequent oxidation (DT treatment) of Ti–45Al–2Nb–2Mn–1B (at.%) titanium aluminide resulted in several oxide layers and a hard Ti3Al as an interlayer between the substrate and the oxide layers. Surface characterization was carried out using X-Ray Diffraction (XRD), Glow Discharge Spectroscopy (GDS), electron microscopy, microhardness tests, ball-on-disk tests and profilometry.

Phase identification and fracture strength of plasma brazed joints of Ti-45Al-2Nb-2Mn-1B with Ti-Ni-Cu filler metals

Plasma brazing of gamma based Ti-45Al-2Nb-2Mn-1B titanium aluminide was investigated using Ti-NiCu filler metals. The joints consisted of irregular or equiaxed grain of a2-Ti3Al phases which contained needle-like or fine particles of s3-Al3NiTi2 particles. With increasing Ni from 15 to 25 wt% in filler metals, the shear fracture strength of the joints increased from ~120