Mechanical properties of Al_2O_3/Si composites fabricated by pressureless infiltration technique

摘要

Two-phase interpenetrating systems with residual microstresses have been shown to exhibit high fracture toughness and strength. In this work, the microstress-induced strengthening concept was applied to Al_2O_3/Si composites. The Composites were fabricated by pressureless infiltration of porous Al_2O_3 preforms with a molten Si. The materials obtained exhibited superior fracture toughness, strength and hardness when compared with technical aluminas having the same volume fraction of Al_2O_3 but containing aluminosilicate glass phases instead of silicon.