Influence of stirring speed on the synthesis of Al/SiC based functionally gradient materials

In the present study, thick aluminum-silicon carbide based functionally gradient materials, with starting weight of 18% SiC were successfully synthesized, using different stirring speeds and an innovative gradient slurry disintegration and deposition technique, The results revealed, in common, an increase in: (a) the weight percentage of SiC particulates. (b) the clustering tendency of SiC, (c) porosity and (d) microhardness, and a reduction in grain size with increasing distance from the base of the functionally gradient material ingots. The results of X-ray diffraction studies indicated no evidence of interfacial reaction products. Furthermore, results revealed an increase in stirring speed increases the homogeneity of SiC particulates' distribution, thus resulting in a decrease in the average gradient of reinforcement along the deposition direction. An attempt is made in this study to establish the trend between processing parameter such as stirring speed with the gradient of SiC particulates realized in the ingots. (C) 2002 Elsevier Science Ltd. All rights reserved.