Optimization of wire feed for GTAW based additive manufacturing

The problem of deposition accuracy is encountered during gas tungsten arc welding (GTAW) based additive manufacturing when wire is fed in side direction. A mathematical model was developed to calculate the wire flying distance in arc zone, according to which displacement compensation was designed to ensure the size accuracy. When arc length was 5 mm and vertical distance of wire tip to tungsten electrode was larger than 3 mm, the horizontal distance between melting wire tip and axis of tungsten electrode was 3.5 mm. The displacement compensation was verified to be effective by forming cross-angle. The model can also be used to achieve bridging transfer, which is beneficial for smooth layer appearance. (C) 2016 Elsevier B.V. All rights reserved.