Rapid reactive synthesis of TiAl3 intermetallics by thermal explosion and its oxidation resistance at high temperature

Porous TiAl3 intermetallics were synthesized from Ti-75 at.％ Al elemental powder mixtures using an energy-saving and rapid reactive method of thermal explosion (TE). The results demonstrated that the actual tem-perature of the compact climbed rapidly from 673 ℃ to 1036 ℃ within 24 s, indicating that an obvious TE reaction occurred during sintering process. The video graphs suggested that the TE in Ti–Al system behaved instant occurrence and overall heating whether from axial or radial direction. The silver wires and NaCl particles that pressed on the surface of the sample disappeared due to the heavy heat released during TE reaction. Only pure TiAl3 phases were synthesized in TE products and the open porosity of 55.4％ was easy to obtain. After high-temperature treatment at 1000 ℃, large amounts of sintering-neck formed and then improved the com-pressive strength of porous TiAl3 materials. Moreover, the mass gain curve of porous TiAl3 intermetallics oxi-dized at 650 ℃ for 120 h exhibited the parabolic oxidation rate law. XPS analysis confirmed that the strong O 1s peak was 531.4 eV which was the typical binding energy of Al2O3. Therefore, the excellent oxidation resistance of porous TiAl3 foams would be considered as good candidate materials for prolonging the service life at high temperatures.