To explore the feasibility of using wire arc additive manufacturing(WAAM)for forming and repairing marine components during ship navigation,this study conducted deposition experiments of ER50-6 steel and investigated ...To explore the feasibility of using wire arc additive manufacturing(WAAM)for forming and repairing marine components during ship navigation,this study conducted deposition experiments of ER50-6 steel and investigated the interference of ship-based vibrations on the WAAM equipment and influence of the characteristics of the arc droplets and sample morphology.The results revealed that the WAAM equipment vibrated with the external vibrations from the surrounding environment,and the welding gun and base plate produced dissimilar vibrations,which yielded unstable arc shapes resembling a bell,trumpet,fan,broom,and other irregular shapes.The mode of the droplet transfer ranged from the stable spray transfer mode to extensive amounts of large droplet transfer and short-circuit transfer.Although the morphology of the obtained sample deteriorated,the fully dense and defect-free interior demonstrated the applicability of ship-based WAAM.展开更多
Plasma sprayed coatings are built up by the accumulation of splats formed by the impacting,spreading and solidifying of molten droplets on the substrate.A three-dimensional computational model including heat transfer ...Plasma sprayed coatings are built up by the accumulation of splats formed by the impacting,spreading and solidifying of molten droplets on the substrate.A three-dimensional computational model including heat transfer and solidification is established to simulate the formation process of a single splat using the computational fluid dynamics(CFD)software,FLUENT.The fluid flow and energy equations are discretized and solved according to typical finite volume method on an unstructured grid.A volume of fluid(VOF)tracking algorithm is used to track the droplet flow with free surface.In order to understand the splat formation mechanism,the process of splat formation caused by impacting and spreading of a molten nickel droplet on a polished mild steel surface is simulated.On this basis,the simulations of impact of a molten droplet on substrate with different conditions including the surface morphology,thermal conductivity,initial temperature of the substrate and the thermal contact resistance are presented.The results clearly show the effect of those parameters on the shape of the final splat and splash behaviors.展开更多
基金supported by Zhejiang Provincial Fundamental Re-search Funds of China(Grant.No.2021J010).
文摘To explore the feasibility of using wire arc additive manufacturing(WAAM)for forming and repairing marine components during ship navigation,this study conducted deposition experiments of ER50-6 steel and investigated the interference of ship-based vibrations on the WAAM equipment and influence of the characteristics of the arc droplets and sample morphology.The results revealed that the WAAM equipment vibrated with the external vibrations from the surrounding environment,and the welding gun and base plate produced dissimilar vibrations,which yielded unstable arc shapes resembling a bell,trumpet,fan,broom,and other irregular shapes.The mode of the droplet transfer ranged from the stable spray transfer mode to extensive amounts of large droplet transfer and short-circuit transfer.Although the morphology of the obtained sample deteriorated,the fully dense and defect-free interior demonstrated the applicability of ship-based WAAM.
文摘Plasma sprayed coatings are built up by the accumulation of splats formed by the impacting,spreading and solidifying of molten droplets on the substrate.A three-dimensional computational model including heat transfer and solidification is established to simulate the formation process of a single splat using the computational fluid dynamics(CFD)software,FLUENT.The fluid flow and energy equations are discretized and solved according to typical finite volume method on an unstructured grid.A volume of fluid(VOF)tracking algorithm is used to track the droplet flow with free surface.In order to understand the splat formation mechanism,the process of splat formation caused by impacting and spreading of a molten nickel droplet on a polished mild steel surface is simulated.On this basis,the simulations of impact of a molten droplet on substrate with different conditions including the surface morphology,thermal conductivity,initial temperature of the substrate and the thermal contact resistance are presented.The results clearly show the effect of those parameters on the shape of the final splat and splash behaviors.
