Mitigation of rotational instabilities using multi-turn solenoid in induction heating-based wire additive manufacturing process

Induction heating-based wire additive manufacturing (IH-WAM) has emerged as a promising heat source for processing high melting point materials. The Lorentz force generated by the interaction between the induced current and the magnetic field strongly influences metal transfer mechanism, often leading to delayed transfer and non-uniform deposition due to its rotational effect. In the current work, the role of magnetic flux density in controlling metal transfer dynamics to achieve favourable material deposition is targeted. The application of a multi-turn solenoid positioned near the induction coil is proposed as a novel approach to mitigate the rotational effect of Lorentz force. A simulation-based study is conducted to determine the optimal orientation of the multi-turn solenoid. A detail investigation is carried out to assess the influence of critical process parameters like wire feed rate, applied solenoid current and number of solenoid turns by analysing the temperature distribution within the fed stock wire. The magnetic field and the corresponding Lorentz force interaction between induction coil and the solenoid is performed to understand the mechanism. The baseline simulation without the solenoid exhibits good agreement with the existing experimental results, validating the developed model. However, the potentiality of magnetic field controlled by using a multi-turn solenoid at optimal design of IH-WAM, shows the way of its reliable application in additive manufacturing of high melting point metals.