METAL MATRIX COMPOSITES DIRECTIONALLY SOLIDIFIED

ALICIA E. ARES; CARLOS E. SCHVEZOV

San Diego, CA

Simposio; ADVANCED COMPOSITES FOR AEROSPACE, MARINE, AND LAND APPLICATIONS; 2014

THE MINERALS, METALS AND MATERIALS SOCIETY

The present work is focused on the study of the effect of the directional solidification on the SiC particles distribution inside the zinc-aluminum matrix during the columnar to equiaxed (CET) phenomenon. The following parameters were measured: cooling rates, temperature gradients, interphase velocities on the solidification microstructure of the MMCs. The following tests were carried out on the composite: optical microscopy, EDS, Vickers microhardness (HV) and Electrochemical Impedance Spectroscopy (EIS) technique. The primary dendrite arm spacing in composite is smaller than in the matrix alloy. The HV values of composites directionally solidified are higher than the HV values of alloys in all structures (columnar, CET and equiaxed). The results also indicate that the corrosion resistance of Zn-Al-SiC composites has demonstrated the improvement in comparison to ZA alloys in 3wt.% NaCl solutions.