Abstract: To explore the feasibility of using wire arc additive manufacturing (WAAM) to form and repair marine components during ship navigation, WAAM equipment was placed on a vibration platform, and the sinusoidal frequency conversion vibrations were used to simulate the ship vibration environment. Thereafter, this study conducted the deposition experiment of ER50-6 carbon steel to investigate the interference of vertical vibrations ranging within 5-25 Hz on the WAAM equipment and the influence of vibration on the morphology, microstructure and properties of the formed parts. The results revealed that the WAAM equipment vibrated with the external environment of vibrations, and the welding gun and base plate produced dissimilar vibrations led to the instability of the arc and the molten pool, the deviation of the droplet, and the change of the heat transfer and solidification behavior during the forming process, causing the changes in the morphology, microstructure and properties of the formed parts. The average grain size of the sample formed without vibration is 7.46 μm, and the tensile strength, lower yield strength and elongation are 495 MPa, 370 MPa, and 29.87%, respectively. In contrast, the average grain size, tensile strength, yield strength and elongation of the samples under different vibration conditions are 5.71 μm to 8.53 μm, 490-500 MPa, 370-385 MPa, 29.17%-34.57%, respectively. In general, all successfully formed parts could meet the performance requirements. However, some vibrations caused the morphology of the formed samples to deteriorate or even failed to form smoothly, thus failing to meet the production and manufacturing requirements, which is the biggest problem to be solved in the future to realize wire arc additive manufacturing on board.

Key words: ship, wire arc additive manufacturing, vibration, steel, morphology, properties