1994 Volume 58 Issue 5 Pages 559-563
Production of Al matrix/TiAl3 dispersion composite materials by an in-situ infiltration-combustion synthesis has been proposed.
According to Semlak and Rhines’ formula for infiltration, the present infiltration-combustion synthesis has been found to consist of two different stages; the initial infiltration and the subsequent enhanced infiltration accompanied by combustion synthesis. The microstructural observation has shown that the present synthesis process consists of the infiltration of Al melt into the green compact, the combustion synthesis reaction and the formation of the porous TiAl3 skeleton, the second infiltration of Al melt into the porous TiAl3 skeleton, which accompanies rearrangement shrinkage of the infiltrated region, and the reinfiltration of Al melt into the non-infiltrated green region. The initial infiltration and the secondary infiltration as analyzed by the Semlak-Rhines equation correspond with the infiltration of the Al melt into the Ti green and the later mixed infiltration process, respectively. The larger particle size of Ti powder (in the present case larger than 100 μm) has been found to discontinuously enhance the second infiltration rate, due to the larger pore space formation, i. e., the larger capillary channel size.
