Reactive Potential for the Simulation of Active Brazing of a Ceramic–Metal Interface

• Published in: Journal of physical chemistry. C Vol. 129; no. 24; pp. 11051 - 11058
• Main Authors: Rothchild, Eric, van Duin, Diana M., Kowalik, Malgorzata, Winter, Ian, Grillet, Anne, van Duin, Adri C. T., Chandross, Michael
• Format: Journal Article
• Language: English
• Published: American Chemical Society 19.06.2025
• Subjects: C: Physical Properties of Materials and Interfaces
• ISSN: 1932-7447; 1932-7455
• DOI: 10.1021/acs.jpcc.5c00228

Contact between liquid metals and ceramics is common to many manufacturing processes but is difficult to model using molecular dynamics due to chemical complexity, high temperature, and a need for charge transfer during simulations. We present a new seven-element (Fe/Ni/Co/Ag/Al/Zr/O) ReaxFF force-field that has been developed to simulate liquid metal–metal and liquid metal–oxide interfaces, with the goal of modeling the brazing of a metal alloy and alumina. This ReaxFF force-field is specifically intended to accurately describe surface tensions and interfacial reactions that control the reactive wetting process that forms the braze joint and contributes to run-out and underfill defects. Results from simulations with this force-field predict a Zr suboxide layer forming on the alumina–filler metal interface and intermetallic formation at the filler metal–solid metal interface. The ReaxFF force-field has some weaknesses, namely, the high melting point of Ag and the instability of the Ag–alumina interface; however, it shows reasonable heats of formation for a wide range of metal and oxide structures, surface tensions for liquid Ag, and reactions at both the filler metal–Kovar and filler metal–alumina interfaces.