Cold-pressing and vacuum arc melting of γ-TiAl based alloys

Abstract

Beta (β) solidifying γ-TiAl intermetallic alloys of nominal composition Ti-48Al, Ti-48Al-2Nb, Ti-48Al-2Nb-0.7Cr alloys have been cold pressed and vacuum arc melted. The Al loss was due to compaction method used prior to the melting technique, since it was evident after compaction that Al particles migrated to the surface in contact with the die facets after cold pressing. Electron backscatter diffraction (EBSD)-orientation mapping demonstrated that the α-precipitation from the parent β-phase follows the Blackburn orientation relationship (BOR). Microstructural characterization of the alloys was studied by scanning electron microscopy (SEM) equipped with energy dispersion spectroscopy (EDS) for micro-analysis. X-ray diffraction (XRD) technique was used to detect phase compositions.