Wetting and interfacial behavior of molten Al–Si alloys on SiC monocrystal substrates: effects of Cu or Zn addition and Pd ion implantation

C-terminated 6H-SiC (0001) single crystal substrates implanted with Pd ions with an energy of 20 keV and three fluences of 5 × 1015, 5 × 1016 and 5 × 1017 ions/cm2 at room temperature. The wetting experiments of SiC by molten Al–10Si, Al–10Si–4Cu and Al–10Si–10Zn were performed by using the sessile drop method in a high vacuum at 1323 K to determine the effects of the third element (Cu and Zn) addition and Pd ion implantation on the wettability of Al–10Si/SiC system. The experimental results showed that the wettability of Al–10Si/SiC system can be improved significantly by adding the 4% Cu with the final contact angle decreasing from ~ 60° to ~ 40°. The final contact angle of Al–10Si/SiC system decreased sharply from ~ 60° to ~ 26° after the addition of 10% Zn, which can be mainly derived from the evaporation behavior of Zn at the interface. The spreading time for reaching the equilibrium or slow spreading stage of the three Al–10Si(– 4Cu, – 10Zn)/SiC systems was prolonged more or less with the increase of Pd implantation dose, which can be mainly attributed to the variation of interfacial interactions between drops and Pd-implanted SiC substrates. Moreover, the final contact angles of Al–10Si/SiC and Al–10Si–4Cu/SiC systems decreased while that of Al–10Si–10Zn/SiC system almost kept constant with increasing the Pd implantation dose.