Properties of a TiAl turbocharger wheel produced by electron beam melting

Powder of alloy Ti-48Al-2Cr-2Nb was used to fabricate turbocharger wheel prototypes by electron beam melting. This additive manufacturing technology uses an electron beam to generate parts by selectively melting the powder in a layer-by-layer way based on CAD data. The parts were fully densified with only minor percentages of build flaws. A loss of Al of about 1.4 wt% is observed, while the levels of impurities are comparable between the powder and the part. Furthermore, the microstructure was investigated after EBM and after EBM + heat treatment. It is characterized by equiaxed grains after EBM. An additional heat treatment transformed this microstructure into a fully lamellar one showing that the microstructure was homogenized.