Non-destructive testing is a critical undertaking in quality and safety of products in industries. Computer tomography has become one of the most effective instruments in the inspection of the components without harming them. This article addresses the operating principle of ndt computed tomography, and its involvement in industrial inspection. The awareness of this technology assists manufacturers to stick to quality as well as minimize risks of failure.
How NDT computed tomography works and its use in industrial inspection
How industrial CT scanning works
Industrial CT scan involves the use of X-rays in producing detailed cross-sectional images of objects in several angles. By rotating the component, hundreds of digital radiographs are collected in a single scan cycle by the system. These is the main principle of the industrial CT technology:
- X-ray projection: X-ray beams are directed through the component and the amount of energy transmitted on the component is detected by the detectors.
- Rotational scanning: This is where the part rotates 360 degrees with thousands of radiographs of varying orientation being taken.
- Reconstruction algorithms: Specialized software manipulates the raw data to form three-dimension digital models.
- Voxel-based representation: The output is in the form of volumetric data in which every voxel lists the density of the material at that point.
- Grey scale analysis: The various densities can be observed as a varying shade and the internal regions and abnormalities can be seen.
Internal defect detection capabilities
Industrial CT exposes defects not visible to human sight or conventional methods of inspection. The technology offers extensive internal inspection excluding disassembling and any destructive cutting. The following are defects that can be detected using the CT scanning:
- Porosity detection: Internal voids and gas pockets of cast or additively manufactured components.
- Crack identification: Fine cracks that may extend in case of stress during the service environment.
- Inclusion location: Foreign particles held in materials during the manufacturing process.
- Wall thickness variations: Locations where the material distribution is not as per the specifications in the design.
- Assembly verification: This is a confirmation that the internal parts fall into place in the assembled products.
Geometric measurement and dimensional analysis
In addition to the inspection of flaws, CT scanning delivers accurate dimensional information of complicated internal designs. These surfaces are hidden and would not be available with traditional measurement tools without sectioning these areas in a destructive manner. The industrial CT has the following capabilities in making measurements:
- Nominal to actual comparison: Color maps showing differences between scanned parts and CAD models.
- Internal feature measurement: Measures of hidden channels, undercuts and internal structures of the complex nature.
- Wall thickness mapping: Full visualization of material distribution in components.
- First article inspection: Checking of new parts fully against design specifications.
- Reverse engineering: Production of the digital models using the models that are already existing and physical.
Frequently asked questions
What are the size parts that can be scanned in with industrial CT?
Depending on the equipment specifications, systems accept parts as small electronic parts as large automotive castings.
How long does a CT scan take?
The duration of scans ranges between minutes in the case of small parts to hours with complex and high-resolution analysis of larger parts.
What is capable of being inspected using CT?
CT inspection applies to metals, plastics, ceramics, composite and multiple materials assemblies.
Destructive to parts CT inspection?
No, CT is fully non-destructive and parts which are tested may be used afterwards.
What detail is revealed by CT?
The resolution has the ability to achieve microns revealing minute details such as small pores, narrow cracks, and exact differences in dimensions.