Hierarchical open cellular porous TiAl manufactured by space holder process

Open-cellular porous TiAl was synthesized by a chemical reaction between titanium and aluminum with a space holder powder (NaCl). Self-propagation of the combustion reaction occurred throughout the specimen when the NaCl addition was below 40vol%, while such a propagating behavior was not observed with higher NaCl additions. TiAl was synthesized after the reaction. Pores were formed in places where the NaCl particles were present. This process shows the hierarchical structure with a bimodal size distribution. [Display omitted] •We developed a processing route for open-cell structured TiAl intermetallics.•The porosity exceeded 80%.•The pores with the same size of the NaCl powder were made after leaching NaCl.•Hierarchical porous structure with a bimodal pore size distribution was obtained.