Wettability and pressureless infiltration mechanism in SiC-Cu systems

The wetting behavior of copper alloys on SiC substrates was studied by a sessile drop technique. The microstructure of SiCp/Cu composites and the pressureless infiltration mechanism were analyzed. The results indicate that Ti and Cr are effective elements to improve the wettability, while Ni, Fe, and Al have minor influence on the improvement of wettability. Non-wetting to wetting transition occurs at 1210 and 1190°C for Cu-3Al-3Ni-9Si and Cu-3Si-2Al-1Ti, respectively. All the copper alloys react with SiC at the interface forming a reaction layer except for Cu-3Al-3Ni-9Si. High Si content favors the suppression of interfacial reaction. The infiltration mechanism during pressureless infiltration is attributed to the decomposition of SiC. The beneficial effect of Fe, Ni, and Al is to favor the dissolution of SiC. The real active element during pressureless infiltration is Si.