Decreasing the infiltration threshold pressure of Al–12 wt% Si into alumina particle compacts by Sn or Pb layers

Pressure infiltration of liquid aluminum alloys into ceramic preforms is a widely used method to fabricate aluminum based composites. Aiming to improve infiltration performance, a novel method is proposed that consists of placing a thin film of a low melting point metal having a surface-tension substantially smaller than that of the alloy. In particular, the effects of a thin layer of tin or lead on infiltration of Al–12 wt% Si into alumina compacts are investigated. The threshold pressure is significantly reduced with respect to that for the alloy, although it is slightly higher than that for pure tin or lead. The performance and characteristics of the method are discussed in some detail.