Almost every industry has seen explosive growth in additive manufacturing (AM or 3D printing) of metal components, either for prototyping or low to medium volume manufacture of often high value and safety critical parts. The powder bed method of fusing successive layers of fine metal powder using a laser or electron beam is one core technology. Alternative methods include direct metal deposition via a nozzle, the latter technique sometimes being combined with subtractive milling and drilling in a machining center. In some systems, dissimilar metals can be combined in the same build cycle to create specific thermal or electrical properties.
The great advantage of AM is that it can produce parts with internal features that are impossible to manufacture by conventional methods, such as curved, conformal cooling channels close to the surface of a mold. AM is also chosen where weight needs to be saved, such as in aerospace and medical component production. Using a touch probe, the resulting filigree structures hidden inside are difficult to inspect without damaging them, therefore call for noncontact methods.