Abstract:
Porous Al
2TiO
5-SiC
w composites were prepared by reaction sintering with
γ-AlOOH, TiO
2 and SiC
w as raw materials.The effects of SiC
w on phases, microstructures, porosity and compressive strength of Al
2TiO
5-SiC
w composites were investigated.The results show that the main phases of the reaction products are Al
2TiO
5, Al
6Si
2O
13, TiC and SiO
2.SiC
w reacts completely with TiO
2 to form TiC and SiO
2 because of the fast decomposition of slender SiC
w.With the addition of SiC
w, the microstructures of Al
2TiO
5 composites are significantly refined.The fine regular TiC grains and Al
6Si
2O
13 grains which distribute between the grain boundaries of Al
2TiO
5 can impede the growth of Al
2TiO
5 grains and improve the compressive strength of the porous Al
2TiO
5 composites.Moreover, because SiC
w changes the packing form of the raw materials and increases the pore size, its porosity increases notably.In addition, some SiO
2 existing among the crystalline grains makes the walls of pores denser and increases the compressive strength of Al
2TiO
5 composites, but the compressive strength will decrease when the content of SiC
w is excessive for the appearance of more glass phase.