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In this paper, laser powder-bed fusion (L-PBF) additive manufacturing (AM) with a high-temperature inductive platform preheating was used to fabricate intermetallic TiAl-alloy samples. The gas atomized (GA) and mechanically alloyed plasma spheroidized (MAPS) powders of the Ti-48Al-2Cr-2Nb (at. %) alloy were used as the feedstock material. The effects of L-PBF process parameters—platform preheating temperature—on the relative density, microstructure, phase composition, and mechanical properties of printed material were evaluated. Crack-free intermetallic samples with a high relative density of 99.9% were fabricated using 900 °C preheating temperature. Scanning electron microscopy and X-Ray diffraction analyses revealed a very fine microstructure consisting of lamellar α2/γ colonies, equiaxed γ grains, and retained β phase. Compressive tests showed superior properties of AM material as compared to the conventional TiAl-alloy. However, increased oxygen content was detected in MAPS powder compared to GA powder (~1.1 wt. % and ~0.1 wt. %, respectively), which resulted in lower compressive strength and strain, but higher microhardness compared to the samples produced from GA powder.

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Synthesis of the Nb-Si in-situ composite was attempted by mechanical alloying of element powders in vario-planetary ball mill. The particles size distribution was measured by laser diffraction, microstructures were examined with scanning electronic microscope, and the phase constituent were analyzed by X-ray diffraction. The amorphization of the Si during mechanical alloying, large amount of deformation of Nb crystal structure, and after all – the formation of supersaturated solid solution of Nb was observed. To stabilize microstructure and phase composition, a spark plasma sintering was attempted. After SPS microstructure consist of three main phases – Nbss, Nb5Si3 and Nb3Si.