Inside Addition

A newly machined part or prototyped component may look and even perform just fine in quality or durability testing, but for those designers who need early proof of structural integrity from the inside out, Battelle (www.battelle.org) is offering a transparent solution.

The non-profit R&D giant recently purchased two 3M X-ray computed tomography (CT) machines to scan mechanical and electromechanical systems, molds, tools, and virtually any type of precision machined part.  Part of Battelle’s Radiographic Imaging Center (www.battelle.org/radiographic), the CT monoliths enable micro-focus imaging for resolution down to 50 microns, or the width of a human hair. They’re also capable of imaging steel parts that are between 1- and 2.5-in. thick in a scanning envelope that is 7-in. wide x 9.3-in. high.  The process works, in effect, by taking a multitude of 2D images around a part (think slices), then mathematically reassembling them, or adding them together, to create a 3D object (think loaf).  Voids or inclusions become visible, even though there’s no clue from the exterior of the part.  (To stay with the bread analogy, you wouldn’t want a loaf with big gaps in it, nor would you want a non-raisin bread to have shriveled grapes inside.)

The scanners can render cross-sectioned views and supply data files capable of being tweaked in many CAD environments.  Contract services run $600 for 2D radiograph scans to $2,400 for CT scans, with additional inspection or consulting on order of $150 an hour.