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Purpose -The purpose of this paper is to investigate the feasibility of using a pulsed Tungsten inert gas arc to fully melt and consolidate stainless steel powder onto a stainless steel substrate. The technology aims to bridge the gap between selective laser sintering or laser melting and wire fed weld deposition by providing good quality and better resolution at a lower cost. Design/methodology/approach -Current settings between 5 and 30 A and frequencies between 0 and 200 Hz were used to consolidate stainless steel powder onto a substrate. Results were catalogued based on surface roughness using white light interferometery to develop a process map. Findings -Velocity independent thresholds of current (17 A minimum) and frequency (20 Hz minimum) were found, with better quality achieved at higher pulse frequencies. The microstructure of the samples were examined showing grain sizes of <3 mm for equiaxed grains and up to 20 mm for the columnar grains. Vickers hardness measurements showed only a 20 point average hardness increase in the HAZ compared to the substrate.Research limitations/implications -The study showed that although it was possible to deposit stainless steel tracks, it was not possible to reduce the track resolution to less than 400 mm at any of the process settings. Originality/value -The research aims to investigate the use of a readily available, low cost, heat source to consolidate metal powder. The suitability of such a heat source for rapid prototyping is investigated using a variety of objective tests to provide a balanced view of its capabilities and limitations.

Additive manufacturing has the capability to build three-dimensional objects directly from a computer model to create complex internal or external geometries. The aim of this research was to design the foundations of a new additive manufacturing technology that could deposit shapes directly in free space without the use of any support structures and eliminate the limitation of