Microstructure Formation of Al/TiAl3 Composite Fabricated by Infiltration-combustion Synthesis (特集 多元系混合粉の焼結過程および焼結機構) Microstructure Formation of Al/TiAl_3 Composite Fabricated by Infiltration-combustion Synthesis
Infiltration-combustion reaction between Ti green compact and molten Al was studied. The infiltration height change obtained by in-situ measurement, showed a linear proportion to the root of immersing time, but an incubation period was observed in the initial stage of the immersion. Using thermocouple embedded in the Ti green compacts, the combustion temperature of Ti powder and molten Al was determined to be about 1360K, which is lower than the calculated adiabatic temperature, 1580K, of the combustion synthesis of TiAl<SUB>3</SUB>. In the preform immersed into molten Al for 30s, granular products were observed at the surfaces of Ti particles. By the observation on the helium-gas-quenched sample, it was confirmed that disintegrated Ti particles and spherical particles of TiAl<SUB>3</SUB> were formed. The crevice between the as-reacted TiAl<SUB>3</SUB> particles was found to be filled with molten Al by the further infiltration to form Al/TiAl<SUB>3</SUB> composite. The final microstructure of this reaction is a cermet type one with about 74 vol% of TiAl<SUB>3</SUB> and the average particle size is about 12μm.
粉体および粉末冶金 44(12), 1100-1106, 1997-12-15
Japan Society of Powder and Powder Metallurgy