Effect of coil current on temperature distribution on extruder in extrusion based metal additive manufacturing using induction heating

The use of induction heating as an energy source in extrusion‐based metal additive manufacturing is gaining attention for its clean, safe, and precise heating. Melting aluminum filament within the extruder and depositing it can be challenging and requires careful control of temperature distribution which, in turn, depends on current and frequency. This study simulates a 2D axisymmetric model consisting of 8 mm outer radius extruder with 0.9 mm inner radius and induction coil using COMSOL Multiphysics software. The temperature distribution on extruder has been analysed by varying the coil current from 200 A to 300 A in steps, while keeping the frequency constant at 55 kHz. Simulation results show that at 200 A, as the extruder's outer surface reached 650 °C, the inner surface attains 610 °C temperature, which is sufficient to melt aluminum filament required for printing. A 40 °C temperature drop has been observed at the inner surface at 200 A, compared to 68 °C at 250 A and 99 °C at 300 A. Further, experimental validation confirmed the simulation results of less temperature drop at 200 A as compared to other current levels. Hence, this current level is preferred for printing aluminum with the developed setup, offering better thermal uniformity, smooth extrusion of molten materials and consistent layer deposition.