Toshio Yamauchi and Yoshinori Nishida
National Industrial Research Institute of Nagoya, Nagoya
In order to make infiltration mechanism clear, pressure change and ram speed were measured when SiC whiskers reinforced aluminum composites were fabricated by squeeze casting. Preforms were deformed due to compression stress during infiltration by aluminum. To analyze the correlation between applied pressure and infiltration front in the preform, the distribution of hardness along infiltration direction in the composite was measured and distribution of volume fraction was calculated by the hardness. The volume fraction increased along the infiltration direction after starting point of compression. Infiltration of preforms by aluminum finished in the course of pressure rise up to 100 MPa. A theoretical expression is derived to describe fluid flow in the preform during the infiltration, on the condition that the pressure on the preform surface starts to rise from zero and when the applied pressure exceeds the compression strength of preform, deformation starts. The starting point of deformation, distribution of volume fraction in the composites can be calculated by the theory in good agreement with experiments. This theory is valid in every cases of the fabrication of composites by squeeze casting.
(Received November 2, 1993)
infiltration mechanism, aluminum composite, squeeze casting, preform deformation, SiC whisker
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