When people think about 3D printing, many assume all printed parts are exactly the same. Additive manufacturers today, however, understand that there is still a considerable amount of variation with 3D printing, and, as a result, advanced inspection methods and tools must be used to ensure printed parts are meeting industry standards.
Because 3D printing is not as repetitive or consistent as it’s often portrayed to be, it requires regular testing and calibration. For this reason, GE developed a scatter|correct function to be used in conjunction with cone beam CT in its v|tome|x m microCT scanner to eliminate the guesswork in additive manufacturing.
Cone beam CT, which images an entire part as it rotates just once between an X-ray source and a detector, is up to 100 times faster than fan beam CT. That’s partially because a fan beam CT scanner X-rays thin slices of a work piece as it rotates and moves linearly in steps through the beam. Those thin slices then have to be reconstructed and combined to represent the full 3D volume. The downside to cone beam CT is that it’s subject to scatter on images.
When GE works with super dense metals, such as chromium cobalt, the radiation causes the materials to scatter resulting in a blurry image. The scatter effect can make it more challenging to get an accurate measurement. Steel, aluminum, composites and multi-material parts are also prone to create scatter on images.
For industrial process control, excellent CT quality at high sample throughput is evident. GE’s proprietary scatter|correct option is a combination of hardware and software advances, allowing users to scan large sample batches in reasonable time as well as significantly reduce scattering artifacts to improve the precision of failure analysis and 3D metrology inspection tasks. The scatter|correct smart function is applied to the first part scanned in a series and the CT scanner applies it to every subsequent part for a clear image and accurate measurement. By combining high precision fan beam CT quality with high throughput of fully automated cone beam CT, the significantly increased inspection productivity allows CT to migrate from R&D applications to serial inspection on the production floor.
Read the full article in Manufacturing Engineering.