Industrial CT scanning for castings, parts and assemblies

The part sits on a rotary stage between an X-ray source and a flat panel detector. It turns through 360 degrees while the system captures projections, and reconstruction software turns them into a stack of voxels, each holding a density value. Analysis software then segments material from air, measures features and colors defects by size. Resolution is tied to geometry. The whole part has to stay in the field of view, so a larger part means larger voxels. A practical rule many labs use is that the voxel size is roughly the part's largest dimension divided by the detector width in pixels, and reliable detection of a pore usually needs it to span at least 2 to 3 voxels. A 20 mm connector can be scanned at a few microns. A 400 mm casting usually lands somewhere around 150 to 300 microns, unless the lab scans regions of interest at higher magnification.

CT is common wherever internal quality matters and parts fit inside a cabinet. Typical work includes first article inspection of castings, porosity acceptance under customer specifications, failure analysis of returned parts, additive manufacturing process qualification, electronics and battery CT scanning, medical device components, plastic injection moldings and aerospace parts with internal passages. Materials range from polymers and composites to aluminum, titanium and thinner steel sections. For large castings where a full volume is not required, radiographic testing is often faster and cheaper, and our comparison of CT vs X-ray inspection explains the trade off.

Metrology CT is a separate service level from general inspection CT. If dimensions will be used for acceptance, ask how the lab traces its measurements and what uncertainty it states for your feature sizes. Guides such as ASTM E1570 (CT examination practice) and ASTM E1695 (CT system performance measurement) are commonly referenced, but always confirm which standard or customer specification governs your job.

1. You send part details: material, dimensions, weight, quantity, the question you need answered and any acceptance criteria.
2. The lab proposes voxel size, scan setup and whether a full scan, region of interest scan or several scans are needed.
3. Parts ship to the lab, or a short visit is arranged for sensitive parts.
4. Scanning takes from minutes for small parts in production mode to several hours for high resolution scans.
5. Reconstruction and analysis follow: porosity, CAD comparison or wall thickness as ordered.
6. You receive a report, images and, if requested, the volume data with a free viewer.

Standard turnaround is commonly 3 to 10 business days. Expedited service is often available at a premium.

Price follows machine time and analyst time. Larger and denser parts need higher energy and longer scans. Finer voxel sizes mean more projections, longer exposure and bigger datasets. Analysis is often the bigger line item than the scan itself, especially porosity reports and CAD comparisons with custom alignment. Batches of identical parts lower the per part price once a fixture and scan template exist. The industrial CT scanning cost guide goes deeper.

Ask whether CT is inside the lab's ISO/IEC 17025 scope, and for aerospace work whether the lab holds NADCAP accreditation that covers computed tomography and personnel qualified under NAS 410. Ask what personnel certification scheme the operators hold (ASNT SNT-TC-1A or CP-189 based, or a central scheme), how system performance is verified and, for metrology, how measurement uncertainty is established. When results go to your customer, confirm who signs the report.