Fabrication of nano-TiC reinforced high Nb-TiAl nanocomposites by electron beam melting

Electron beam melting (EBM) has been successfully applied to fabricate TiC reinforced high Nb-containing TiAl matrix (TiC/Nb-TiAl) nanocomposite. The optimised combination of focus offset and line energy in the melt stage have been developed to achieve a uniformly distributed nano-TiC particles within the TiAl matrix. The EBM TiC/Nb-TiAl nanocomposite has a microhardness of 393 ± 31 HV , that is 24% higher than that for high Nb-TiAl alloy alone. It is interesting to note that the uniformly distributed nano-TiC particles lead to the formation of equiaxed α -phase in TiAl matrix, instead of those commonly observed γ-phase in previous EBM γ-TiAl work. 0.2 2