Influence of the surfacing mode on the microstructure of the deposited metal produced by wire arc additive manufacturing using Al-Mg alloy

This paper presents studies of the influence of the parameters of the pulsed arc surfacing mode on the microstructure of the deposited metal produced by Wire Arc Additive Manufacturing (WAAM) using the Al-Mg alloy (AMg5 wire) with an argon gas-shield, which is being intensively developed today. The dependence of the influence of the surfacing mode on the relative size of the grain and its shape is established. With an increase in the frequency of current pulses in the range from 13 to 55 Hz, the average conditional grain size increases from 98 to 236 mu m. The conditional grain eccentricity also increases. The dependence of the average conditional grain size on the heat input was not found. With an increase in heat input, a decrease in the grain eccentricity was observed. The dependence of the hardness of the deposited metal on the surfacing mode was not noticed. The average value of hardness lies in the range of 66-68 HV. The results of the work are recommended to be used to select the pulse frequency (which also affects the droplet size) in the development of technologies for wire-arc additive manufacturing from aluminum alloys.