Metallurgical and Materials Transactions A ( IF 1.985 ) Pub Date : 2019-11-11 , DOI: 10.1007/s11661-019-05531-3
Honglin Zhang, Xing-Qiu Chen, Bin Xu, Mingyue Sun, Dianzhong Li

The removal of interfacial oxides is essential in solid-state bonding to obtain high-performance joints. A recent work reported that the dissolution of MnCr2O4 at the hot compression bonding (HCB) interface of 316LN stainless steel improved the mechanical properties of joints. The evolution behaviors of interfacial oxides behind it should be further understood. In this study, the thermodynamic stability of MnCr2O4 and decomposition mechanisms of interfacial oxides in HCB was studied by combining the first-principles calculations with thermodynamics approach. The results obtained within GGA + U method were compared with experiments and in a good agreement with previous calculated results. The predicted stability region of MnCr2O4 was built by drawing the Mn-Cr-O phase diagram. The transition of its possibly coexisting binary oxides was understood in detail with respect to the environmental conditions. The interfacial oxides evolution in HCB process was proposed based on the variation of oxygen chemical potential. It predicted that MnCr2O4 forms during the heating period of HCB with the presence of binary oxides of Mn and Cr. All possible interfacial oxides decompose into metal phases and oxygen atoms when $$\Delta \mu_{\text{O}}$$ is below − 386.97 kJ/mol.

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