Characterization of TiAl-Be Alloys Produced by Electric Current Activated Sintering

N. Ergin, O. Ozdemir Sakarya University, Technology Faculty, Department of Metallurgy and Materials Engineering, 54187 Esentepe Campus, Sakarya, Turkey

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In this study, TiAl-Be intermetallic alloys were produced by electric current-activated sintering (ECAS) method in open air under the uniaxial pressure of 200 MPa at a current of 1100-1200 A, applied for 2 minutes. Aluminum powder with 15 μm size (99%), titanium powder with less than 45 μm size (99.5%) and beryllium powder with size less than 44 μm size (99%) were used in order to produce the samples. The elemental powders were mixed in the stoichiometric ratio of 1:1, corresponding to molar proportion of TiAl intermetallic phases, and then the mixed powders were synthesized. While three phases were found in the TiAl samples after the microstructural examination, multi-phases were observed in the TiAl-5 wt.% Be samples. XRD studies revealed that the TiAl intermetallic alloys include TiAl, Ti3Al and TiAl3 phases. In addition to these three phases, Be2Ti phase was also found in the TiAl-5 wt.% Be alloys. The relative densities of the TiAl and TiAl-5 wt.% Be samples, measured according to Archimedes' principle, were approximately 96.4% and 94.5%. Micro-hardness of TiAl and TiAl-5 wt.% Be samples was approximately 426 ± 34 and 478 ± 62 HV0.1, respectively.

DOI: 10.12693/APhysPolA.127.1103 PACS numbers: 81.05.Bx, 81.20.Ev, 81.40.Cd