Revisiting the Dissolution Behavior of Interfacial Oxides in Hot-Compression Bonding of a Fe-Cr-Ni Stainless Steel

Interfacial oxides can be removed by thermodynamic decomposition in the metallic solid-state bonding. Despite adequate observations, the dissolution behavior is not yet well understood. Based on the hot-compression bonding experiments of a Fe-Cr-Ni stainless steel, first-principles calculations are adopted to reveal the diffusion of oxygen in the Cr₂O₃/FCC-Fe heterostructure to identify the dissolution process. The results show that the heterogeneous interface favors the formation of oxygen vacancies, and the oxygen prefers to diffuse through the facet of coordination tetrahedron of Cr atoms than their bridge-site. The dissolution of the oxides is dominated by the diffusion of dissociated oxygen to the interface due to its high activation energy of 720 kJ·mol^-1, while the heterogeneous interface provides a favorable transport channel to allow the oxygen diffuse into iron matrix.