Thermal analysis of synchronous induction-assisted laser deposition of Ti-6Al-4V using different laser-induction interaction modes

Synchronous induction-assisted laser deposition (SILD) can be used to address issues that arise from the extreme thermal behavior that occurs during direct energy deposition (DED). However, the incorporation of induction heating simultaneously renders the thermal behavior during SILD more flexible and complicated. This study established a 3-D transient finite element model to elucidate the thermal behavior during SILD with a simplified inductive heat source. The experimental and analytical results were in close agreement. The effect of the interaction mode of the heat sources on the thermal behavior was analyzed using the verified model; further, the results confirmed that the interaction mode of the heat sources significantly affected the thermal behavior, especially in the case of the “alternate” mode. It should also be noted that although it was more difficult to balance the thermal behavior, the cooling rate at the β transus temperature of Ti-6Al-4 V decreased from 82 ℃/s to 23 ℃/s; further, the maximum temperature gradient in front of the solid-liquid interface decreased from 5.8 × 10⁵ ℃/m to 4.4 × 10⁵ ℃/m in the “alternate” mode, which was relative to the “without induction heating” and “synchronous” modes.