Manufacturing B 4 C-(Al, Si) composite materials by metal alloy infiltration Academic Article uri icon

abstract

  • Abstract The chemical interaction of porous B 4 C with molten Al during the infiltration step and the post-infiltrating heat treatment leads to the formation of a whole range of binary and ternary phases which affect directly the microstructure and the mechanical properties of the composite material. The formation of Al 4 C 3 is undesirable because its presence causes a substantial decrease of the mechanical properties. In the present work, the effect of alloying aluminum with silicon on the formation of undesirable aluminum carbide in the infiltrated composites was investigated experimentally. The presence of Si improves the wetting and accelerates the penetration of the molten alloy into porous preforms. The addition of 40 wt.% Si to Al ensures that the final concentration of Si within the molten Al is higher than the threshold value (about 12 wt.%) that is necessary for preventing the formation of …

publication date

  • December 20, 2003