NumericalSimulation of the Electromagnetic Stirring Process for 7075 Aluminium Alloy Magnetohydrodynamic Molten Droplet-based Additive Manufacturing
Author of the article:CHEN Hao, WANG Yongxin, LUO Xian, HU Rui, HUO Da
Author's Workplace:State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an 710072, China
Key Words:magnetohydrodynamic; molten droplet-based additive manufacturing; 7075 aluminium alloy; electromagnetic stirring; numerical simulation
Abstract:
This work proposed a strategy in which an electromagnetic stirring process was added to magnetohydrodynamic molten metal droplet-based additive manufacturing to increase the melt composition uniformity and remove impurity gas. By numerical simulation analysis, the stirring magnetic field traits of three different types of coil winding configurations were systematically investigated, and the optimal electromagnetic stirring model was determined on the basis of the trajectories and velocity distributions of the flow field. The results show that when windings with the same phase are arranged adjacently in pairs and subsequently ordered according to phase differences, the resulting travelling wave magnetic field electromagnetic stirring model is more suitable for molten droplet additive manufacturing processes, as it exhibits complete spatial penetration characteristics in the molten metal flow field and provides the highest stirring intensity. The influence of the current amplitude and frequency on the stirring intensity was also investigated. Increasing the coil current amplitude and frequency can enhance the stirring intensity to a certain extent. The simulation results indicate that the optimal process parameters are a current amplitude of 300 A and a coil frequency of 5 Hz.