EVALUATION OF THE WETTABILITY OF AL-PB AND AL-SN ALLOYS WITH SIC AND AL2O3 PARTICULATES BY MEANS OF PRESSURE INFILTRATION

The wettability of SiC and Al2O3 particulates by Al-Pb and Al-Sn alloys has been evaluated by means of pressure infiltration. All infiltrations were carried out in air. The resulting threshold pressures decrease logarithmically with the content of the alloying element, similarly to the experimental data for the surface tension of these alloys reported in the literature. In the case of SiC, the threshold pressure decreases with the alloy content at a higher rate than the surface tension. In contrast, although the results for the alumina particulates are less clear, the tendency seems to be the opposite. These results are interpreted in terms of differences in wettability of silicon carbide and alumina particulates by oxidized aluminium-tin and aluminium-lead alloys.