Industrial inspection services are a critical part in the manufacturing process. Metrology and inspections are used for first article testing, both part to part comparisons and part to CAD comparisons, and for quality control. Unfortunately, many traditional metrology and inspection methods, such as coordinated measuring machines (CMM) and cartesian measurement arms involve touch probing, which is expensive and time consuming, and in some cases, destroys the part in the process.
However, it is becoming more common in the industrial inspection industry to use the same CT scan calibration that is used in the medical field to inspect industrial parts closely, from images that are captured with digital x-rays. This gives manufacturers the benefit of having the key part information turned around quickly and relatively inexpensively and while not harming the part itself, in the same way that the CT scan calibrations can be used to closely inspect the inside of the human body, without harming the person.
How CT scan calibrations work in the industrial world.
When a part is being inspected through CT scan calibration, it is rotated in a full circle while hundreds to thousands (depending on the level of detail needed) of digital x-ray photos are captured, inside and out, from every angle. These images are then compiled to create a 3-D video of the part, which can be used for analysis and testing. Once the 3-D image of the part is captured, the physical part itself is no longer needed for analysis.
A Few Practical Uses for CT Scan Calibration in the Industrial World
- Failure analysis. The 3-D video of the part and its function are used to create a digital walk-through of the part in operation, to evaluate how it functions and to ensure that it works as it should. This also enables engineers to gain key metrics, such as the density, porosity, and measurements of the inside of the part.
- Porosity analysis. The 3-D image of the part can be used to measure the ratio of air to material that the part is composed of, which gives engineers detailed porosity metrics. This can be used to determine the volume and placement of the internal cavity.
- Wall thickness analysis. The CT scan of the part can be used to calculate the internal and external measurements of the part, which determines the thickness of the walls. This is important for ensuring that the product is matching the design specifics of the part.
- Part to part comparison. When the CT scan is taken of two identical parts (or parts that should be identical), the measurements for each part can be closely compared to ensure there are no differences. This is often used with reverse engineering, to make sure the prototype is exactly like the original.
- Part to CAD comparisons.
After a part is manufactured based on a CAD model ofit, the CT scan of the part can be used to compare any distinctions between the CAD plans in the part itself. This is important to ensure quality of the prototype.
- First article inspections. Before a retailer purchases a large quantity of parts from the manufacturer, they often use CT scans of the first part to ensure quality of it.
- Fiber analysis. Using the data set created from a CT scan of the part give engineers the ability to analyze the part all the way down to the fibers. By collecting the length, diameter, and percent direction of the fibers, they can gain detailed information about the part that was never available before with conventional metrology techniques.
- Reverse engineering. The internal and external measurements of a CT scan can be used to reverse engineer a part that is needed for manufacturing, but is no longer available.
When CT Scanning is Valuable for Part Inspection
Any time detailed metrics are needed for a part, CT scans of it can easily produce the information. This method is commonly used during the pre-production and prototype stage of manufaction while the part is in development. It is used for lot inspection to ensure quality before the assembly line really cranks up. It is used in the failure inspection phase to prevent costly recalls. It is used for reverse engineering, to recreate old parts. Every stage of manufacturing benefits from CT scanning calibration.