Abstract
To clarify the formation mechanism of the reaction layer, the behaviour of elements composing Si3N4 and brazing filler at the brazed interface was examined by SEM observation and EPMA analysis. The erosion depth of the brazed ceramic surface was also evaluated by surface roughness measurement, in order to examine the relation between the erosion depth and the brazing condition. The results of EPMA analysis suggested that Si3N4 was eroded with diffusion of Si and N to reaction layer. According to the erosion test using Ag-Cu-4 mass%Ti, the isothermal erosion depth of Si3N4 increased proportional to square root of brazing time in the temperature range of 1123 K to 1223 K. The temperature dependence of the rate constants fits an Arrhenius equation yielding activation energies of 127.5 kJ/mol.
