Effects of temperature on pressure infiltration of liquid Al and Al-12wt.%Si alloy into packed SiC particles

The effects of temperature on pressure infiltration of packed SiC particles by liquid Al and the eutectic Al-12wt.%Si alloy have been investigated over the temperature range 923-1273 K. Below 1173 K. the threshold pressure P-0 for infiltration of pure Al slightly (and linearly) decreases with temperature. At that temperature a sharp drop occurs, followed by a faster decrease of P-0. The contact angle theta derived from the threshold pressure data shows a similar behavior. Results for the Al-Si eutectic alloy are very similar for temperatures below 1173 K, but, above this temperature.. the threshold pressure decreases faster than for pure Al. These results are consistent with contact angle data derived from sessile drop experiments. In addition compact permeability is significantly reduced for T > 1173 K, a result likely related to the reaction between aluminum and SiC. (c) 2005 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.