A non-isothermal multi-phase field approach to model the meltpool and IMC grains interaction in Ti-Au material

This study introduces a combined phase-field multi-physics approach to simulate laser-induced phase transformations and microstructural evolution in the Ti-Au alloy system, which is crucial for advancing additive manufacturing processes. By varying laser parameters, such as irradiance and scan speed, we used simulations to quantify phase areas and free energy dynamics, revealing intricate interplays between heat flow and chemical diffusion. The simulations show that under maximum heat flux conditions (150 kW/cm 2 at 4 nm/ms), meltpool depth reached 180 nm, surpassing the 158 nm depth observed at 134.6 kW/cm 2 . Moreover, the growth of Ti 3 Au intermetallic compound (IMC) formed due to the interfacial reaction was studied. IMC layer thickness peaked at 364 nm under higher irradiance, marking a 25% increase over lower irradiance conditions. Analysis of Lewis Number revealed that meltpool diffusion occurs more slowly than heat transfer. • Composition and thermal fields constituting the driving force. • Featuring meltpool dynamics and intermetallic grains evolution. • Linking process parameters to the material structure evolution. • Methodology to distinguish heat flow and chemical diffusion fronts.