Which of the following additive manufacturing technique(s) can use a wire as a feed stock material?

The correct answer/options are Directed energy deposition processes and Fused deposition modelling.

Additive manufacturing (AM) processes are classified based on the state of the raw material (feedstock) they use, such as liquid, powder, filament/wire, or sheets. Let's analyze each of the given options to understand which techniques can utilize a wire as feedstock:

1. Fused Deposition Modelling (FDM):
FDM is a material extrusion process where a thermoplastic material is fed through a heated nozzle. While FDM traditionally uses thermoplastic filaments (spooled wires of plastic), the feed mechanism operates by pushing a wire-like filament feedstock into the liquefier. Thus, it uses a wire/filament as feedstock.

2. Directed Energy Deposition (DED):
DED processes use focused thermal energy (such as a laser, electron beam, or electric arc) to fuse materials by melting them as they are being deposited. DED systems typically feed feedstock in either powder or wire form. Wire-based DED (often referred to as Wire Arc Additive Manufacturing or Electron Beam Additive Manufacturing) specifically utilizes a metal wire fed directly into the melt pool. Therefore, DED processes can use a wire as feedstock.

3. Stereolithography (SLA) & Selective Laser Sintering (SLS):
SLA uses a liquid photopolymer resin as feedstock, which is cured by a UV laser, whereas SLS utilizes a bed of fine powder (typically polymer or metal) sintered by a laser. Neither of these techniques can use a wire feedstock.

Consequently, the techniques that can use a wire as feedstock are Directed energy deposition processes and Fused deposition modelling.