A phase-field study on the formation of the intermetallic Al2Au phase in the Al-Au system

作者：Wang Fei^*; Nestler Britta

来源：Acta Materialia, 2015, 95: 65-73.

DOI：10.1016/j.actamat.2015.05.002

• Al-Au
• Phase-field
• Intermetallic
• Lateral spreading
• Vertical growth

The growth mechanism of the intermetallic Al2Au phase in the Al-Au system during the process of soldering is investigated by a multiphase phase-field model. With the aid of the assessed thermodynamic data (Li et al., 2004), the binary phase diagram of the Al-Au system is reconstructed by assuming a regular solution model for the intermetallic Al2Au phase. The simulation setup is composed by placing an Al-liquid droplet on top of an Au-solid substrate. To capture the phase boundary evolution of the droplet and substrate interface with respect to the surrounding vacuum phase, the binary phase diagram is extended to a ternary model system at one particular temperature between the melting points of Al and Au. Due to diffusion of Al and Au at the droplet/substrate interface, intermetallic phase is formed. In simulations, we investigate the lateral and vertical growth velocities of the intermetallic phase as a function of the surface energy of liquid-intermetallic. Further, the instability of the liquid(Al)solid(Au) interface is analyzed by examining the shrinking speed of the liquid-solid interface affected by the diffusivity of Au.

• 出版日期2015-8-15