Influences of surface polarity and Pd ion implantation on the wettability of Al-12Si(-2 Mg)/SiC systems

N-type 6H-SiC (0001) single crystals were implanted with 20 keV Pd ions at three doses of 5 × 1015, 5 × 1016 and 5 × 1017 ions/cm2 at room temperature. The wetting of SiC single crystal by molten Al-12Si and Al-12Si-2Mg were performed by using the sessile drop method in a high vacuum at 1323 K. The influences of surface polarity and Pd ion implantation on the wettability of Al-12Si(-2 Mg)/SiC systems were investigated. The experimental results showed that the equilibrium contact angles of molten Al-12Si and Al-12Si-2Mg on the C-terminated SiC were respectively lower than those on the Si-terminated SiC, which can be related to the formation of Al4C3 at the interface. The wettability of Al-12Si/C(Si)-terminated SiC systems was improved with the 2 wt% Mg addition due to the decrease of the solid-liquid surface energy (σSL) originated from the enhancement of interfacial interactions. Moreover, the equilibrium contact angles of Al-12Si/C(Si)-terminated SiC systems decreased more or less with the Pd implantation dose increasing, while those of Al-12Si-2Mg/C(Si)-terminated SiC systems gradually increased, which can be mainly attributed to the variation of interfacial interactions of Al-12Si(-Mg)/SiC systems.