Pore Channel Formation of Porous TiAl3 Intermetallics Prepared by Thermal Explosion with Space Holder Process

Porous TiAl3 intermetallic compounds were fabricated through thermal explosion(TE) by adding 60% volume of NaCl space holder. The mechanism of pore channel formation and microstructure in TiAl3 sintered disks was investigated. The research on pore channels was from micro to macro, and the formation process of pore channels was systematically described. It was found that the pore structure of TiAl3 was composed of three parts, macropores left by the space holder, thermal explosion micropores, and intergranular micropores. The raw material particle size controlled the morphology of micropores. Three kinds of channels were formed, crack microchannels, thermal explosion microchannels, and macroporous channels. The formation and propagation of crack microchannels were due to the excessive expansion of large Ti particles. The pore window structure between the in-situ pores of large Al particles was the main reason for the thermal explosion microchannel. Crack microchannels and thermal explosion microchannels were the media of macroporous channels. Different channel structures had different effects on the mechanical properties of TiAl3 products. Rich and connected pore channels enhanced direct contact between fluid and pore wall and improved filtration of porous TiAl3 intermetallic compounds.