| Countergravity, pressure-assisted liquid metal infiltration of suitably packed porous compacts of platelet shaped single crystals of alpha (Hexagonal) silicon carbide was used to study (i) particulate wettability and threshold phenomenon during ingression of liquid Al alloy (2014) through SiC compacts, (ii) the kinetics of infiltration, and (iii) the effects of fluid flow and SiC distribution on the solidification microstructures of the matrix. The major experimental variables included: infiltration pressure (280 to 825 kPa), infiltration time (3 to 30 min.), powder preheat time (3 to 15 min.), size of SiC (45 to 500 microns), and surface chemistry of SiC (plain, Cu coated and Ni coated).;Application of external pressure in excess of a pressure threshold (P... |
