Structure of wetting front in the Ag-Cu-Ti/SiC reactive system

The nanostructure around the wetting triple line in the Ag-Cu-Ti/SiC reacti ve wetting system was studied. The reaction product consisted of an upper s eparated Ti5Si3 layer more than 20 nm thick, and a lower TiC layer less tha n 10 nm thick was observed exceeding the front line of Ag-Cu-Ti brazing met al. At the top of the reaction product, the lower TiC layer was observed to project beyond the front line of the upper Ti5Si3 layer. In Ag-Cu-Ti/Si3N4 system, structural change around the wetting triple line as reactive wetti ng progressed has been reported, however, in the Ag-Cu-Ti/SiC system, the s tructure around the triple line did not change. The difference between the two systems was explained from the viewpoint of a stable phase change with the decrease of Ti activity as reactive wetting progressed. (C) 2000 Kluwer Academic Publishers.