Effects of milling thickness on wire deposition accuracy of hybrid additive/subtractive manufacturing

A hybrid technique integrating wire arc additive manufacturing (WAAM) and milling was studied using Al5Si aluminium alloy. The results showed both the surface roughness and the machining allowance of this hybrid additive/subtractive manufacturing were reduced in comparison with pure WAAM when the milling thickness was in the range of 0.4-1.2 mm. The accuracy improvement was discussed in terms of the melt flow. It was found that after the surface was milled to a plane, the melt flow changed from the downward along camber surface to the outward and backflow on the plane. This change slowed down the velocity of melt flow, and then reduces the fluctuation of the side profile of deposited thin wall.