Fabrication of metal matrix composite by infiltration process - part 2: experimental study

A method for the fabrication of metal matrix composite (MMC) is reported. Experimental work was carried out to achieve the results of an established mathematical model. The structure and soundness of the MMC produced by this method was studied. In this method pressurized air is used to infiltrate the melt through a porous column of alumina particulate. Firstly, lead is used as the model metal of the matrix, with alumina particles as the reinforcement material. The infiltration pressure used was 0.2 and 0.3 MPa, the void fraction of the porous column was 0.38 and 0.42 and the infiltration time was 2-10 s. The results show a good agreement between the calculated and experimental values of melt penetration height in the porous column. Secondly, an Al(Al2O3)p MMC has been prepared using the same technique in a closed capsule at different pressures of 0.3, 0.5, 0.7 and 1 MPa, and with alumina particles size ranges of 63-250 mu m and a constant infiltration time of 30 s. The results indicate that the particles are uniformly distributed in the matrix for a certain length along the rods produced. Also, the percentage of pores increased with decrease in either the pressure or the particle size range used. (C) 1999 Elsevier Science S.A. All rights reserved.