Investigation of pulse advance cold metal transfer on aluminium wire arc additive manufacturing

This study sought to investigate the effect of process parameters on linear wall dimensions when using the pulse advance cold metal transfer process for aluminium wire arc additive manufacturing. Firstly, a process envelope was developed and the limit of the wire feed speed to travel speed ratio determined. A limiting range of wire feed speeds was also identified. The results showed that the key factor for wall dimensions is the wire feed speed to travel speed ratio. It was observed that increasing the ratio increased the effective wall width, total wall width, layer height and surface waviness. Microstructure analysis conducted showed that walls were characterised mainly by equiaxed and dendrite grains. It was observed that the porosity increased with increasing wire feed speed to travel speed ratio. Using this process, an effective wall width range of 4.9-8 mm was achieved.