Evaluation of hardness of the interfacial reaction products at the alumina–stainless steel brazed interface by modeling of nanoindentation results

We have analyzed the 304 stainless steel (SS)–(Ag–Cu–Ti)–alumina brazed interface using scanning electron microscopy, electron probe microanalysis and nanoindentation. The SS interface exhibits increased bond strength and a larger diffusion zone compared to the alumina interface. In order to explain the nature of variation in hardness, we have fitted a second-degree Hermite polynomial-based model to the experimental observations of the nanoindentation results, across the reaction product zone of both interfaces.