By Jesse Garant Metrology Center
For 3d Printed & Additive part types, there are 3 primary areas that have had a large amount of success when adopting CT Scanning. These areas include: Validation of Must Run Parts Typically in high performance Additive applications, printed components cannot fail when in use. Parts and assemblies that fail to function properly could compromise the application they are being used for resulting in an equipment or catastrophic failure. CT inspection can provide another level of reassurance on top of traditional inspection techniques to further reduce the risk of a compromised product escape. Visualizing the internal cross-sectional slices of a CAT scanned part or identifying physical geometry variations has been proven to aid manufacturing companies and their suppliers to ensure a quality product is being used. Going a step further surface profile validation, wall thickness variations, and first article inspection (FAI) can also be completed in a free state environment while preserving the integrity of the original component to allow it to undergo further testing or be approved for use in a production environment. Depending on the overall cost or key function of the product, sometimes CT inspection of every sample can be cost justified in very specific scenarios. For very delicate or high functioning parts residual powders, pores, inclusions, and cracks can also be detected with CT scanning. Over the years CT scanning has proven to be highly beneficial for validating lightweight components, heat exchangers, high performance products, and components that could not be manufactured with subtractive manufacturing means. Although polymer-based materials can be easily inspected with CT scanning, typically the value and the importance of the product is not high enough to warrant such a costly inspection. Therefore most additive parts that are inspected with computed tomography are alloy based and manufactured out of aluminum, titanium, stainless steel, Inconel, copper, or nickel. Printer Performance Validation For Additive part types, X-Ray and CT inspection of test bars and cylinders has proven to be highly beneficial for verifying the performance of a high precision metal additive printer. When the optimum printing parameter needs to be verified for a specific material, just selecting a general operating parameter and material isn't enough in some cases. Sometimes the print settings need to be 100% verified for print quality and by print location. Manufacturing a series of cylinders printed at different locations with different print parameters has proven to be highly beneficial when paired with CT scanning. Not only can CT scanning identify the sample with the lowest number of defects in each area, but it can also verify the print quality through the print bed. Once optimum print settings have been validated, test bars can be printed, scanned, and ran through performance testing to further verify the print quality, compression, and tensile strength. Benefiting from Service Labs As the technology is rapidly being adopted and standards are evolving all the time, utilizing a certified CT service lab ensures proper compliance to the latest standards and requirements. This ensures the project is completed according to a verifiable process and the experienced lab can not only complete the results but communicate the results. As computed tomography data is complex, large in file size, and new for some people; effective communication is key to ensure all parties are properly informed of the results for effective decisions to be made.
