In certain aspects of the disclosure, a method includes creating ink specimens. The method includes solidifying, via solvent evaporation, the ink specimens to identify Ni powders and Ti powders. The method includes debinding and pre-sintering the Ni powders and the Ti powders to form a porous NiTi skeleton. The method includes infiltrating the porous NiTi skeleton with a transient liquid. The method includes reaction sintering the NiTi of the porous NiTi skeleton and the Sn to reactively form TiNiSn. Ternary-phase thermoelectric materials formed by the method are also provided.