Parts produced via Metal 3D Printing are weldable but material properties can change locally. More severe are the possible deformations of the part after the welding process. Deformations can, however, be prevented by adequate welding. Material properties on welds of metal 3D printed parts are not yet available today and an important learning curve is still ahead. A redesign of the welding interface is often necessary in order to get the best results.

• Stainless Steel is weldable. It’s not the easiest steel to weld, but weldable.
  
• Aluminum is also weldable. The challenge with Aluminum is the state of the molten mass during the welding process. It has a very low viscosity, which means that the molten material easily “flows out” of the welding spot.
  
• Titanium is in general also weldable, but this is usually done under vacuum and with electron beam welding. However, Electron beam welding, however, is very expensive and something for specialists.
• Inconel has a good weldability in as-built or age-hardened state. The alloy is designed with a high amount of iron to overcome the general low weldability of super alloys and particularly their susceptibility to cracks in heat-affected zone of welds. Inconel is most commonly welded using tungsten inert gas welding.