CT-Assisted Solid Freeform Fabrication

摘要

Computed Tomography (CT) is a radiographic inspection method that uses a computerto reconstruct a cross sectional image of an object from a set of in line X-ray transmission measurements. CT was introduced in the early 1970's as a neurological examination technique and later extended to industrial applications by Advanced Research and Applications Corporation (ARACOR) and others. The original medical acronym, CAT, is still widely used and is likely to be familiar to the reader. The technology provides an ideal examination technique whenever the primary goal is to locate and size planar or volumetric detail in three dimensions. Because of the relatively good penetrability of X rays, as well as the sensitivity of absorption cross sections to the density and atomic number of matter, CT permits the nondestructive physical and, to a limited extent, chemical characterization of the internal nature of objects. And since the method is X-ray based, it applies equally well to metallic and non-metallic specimens, solid and fibrous materials, smooth and irregularly surfaced parts.