Shape control of wire arc additive manufacturing for aluminum alloy in different substrate heat sink
In this paper,the heat dissipation condition of the molten pool is used to construct the local differential heat transfer characteristics of the molten pool in terms of the substrate sizes,and the influence of the heat sink conditions(transverse heat transfer-substrate width,longitudinal heat trans-fer-substrate thickness)on the forming geometry and shape are explored experimentally,so that the heat dissipation conditions matching the heat input can be explored from the outside of the molten pool,which is a relatively simple heat transfer process,to achieve shape control in wire arc additive manufacturing.The experimental results show that the effect of the substrate on the morphology of the deposition layer is mainly realized by changing the heat dissipation around the molten pool.When the heat input is insufficient,the single deposition layer will form dewiness and necking defects at the arc striking zone.The larger the size of the substrate,the stronger the heat dissipation capacity,the smaller the width and the higher the height of the deposition layer.The effect of the substrate on the deposition layer gradually decreases with the increase of the deposition height,and eventually stabilizes under different heat sinks.The strategy of increasing the arc-starting current and suspending at arc extinguishing zone to cope with the change of substrate heat sink conditions can avoid the defects such as false welding and molten pool flow and improve the quality of multi-layer deposition geometry forming.
万方数据
维普
