Vendors in the additive industry continue to develop programs for in-process monitoring.

This latest offering comes from Wayland Additive. During the development of its Calibur3 platform with NeuBeam technology, the design team developed in-process monitoring as a key function.

The original plans to launch the Calibur3 machine in January were delayed due to the Covid-19 lockdown restrictions. So, the global virtual launch is now scheduled for March 16th 2021. The physical launch, which will see Wayland welcoming visitors to the now complete Development Suite for production partnerships in Huddersfield, has been postponed until May 19th sensitive to the latest travel regulations and guidelines.

The approach to in-process monitoring (IPM) uses three independant but complementary IPM processes. The collective benefits of infrared cameras, structured light scanning, and electron imaging provide extensive and detailed data on every part that comes off a Calbur3 system.

• Every Calibur3 includes a high-speed CMOS camera working in the NIR range and operating at four Megapixels at 100 FPS, up to a maximum of 25,000 FPS at small resolution. The IR camera measures temperatures in the range of 600 to 1500°C to provide absolute temperature measurements and cooling rates as identify phase changes. In this way the IR Camera can provide real time temperature mapping. Measured temperatures can be presented in 3D for visualization and the resulting plot can be interactively panned, zoomed and rotated — also in real-time.

This type of thermal mapping can be used to monitor part dimensional accuracy, powder spreading during the build, energy absorption and any out-of-plane defects not visible to the naked eye. This capability is particularly advantageous for rapid material development.

• The structured light scanning system in the Calibur3 is based on the synchronization of a second CMOS camera and a light projector system. This system permits multiple fringe patterns to be projected onto the build area and captured by the camera. The system can calculate the z-axis (height) of every point on the build and thus produce an accurate height surface map of the powder bed. Any out of plane defects, on any layer in the build, caused by powder spreading or part swelling for instance, can then be easily detected and quantified.

This system allows post-build defect and quality analysis to assist with process development, but Wayland’s technology roadmap will see this integrated into closed loop machine control algorithms over the next couple of years.

• The backscattered electron detector — or electron imaging — process detects the primary electrons that have been scattered back from the nuclei of atoms in the target material. Different element compositions and phases will interact differently with the electrons and thus appear distinct within the build chamber. The BED process can also detect localized ionization in the vicinity of the meltpool. This capability is unique to Wayland Additive’s NeuBeam process and the active charge neutralization system.

This monitoring process provides data about the element composition and the grain structure within the parts that can be analyzed and used to support traceability and demonstrate internal quality of the parts.

This comprehensive monitoring approach improves the quality of the parts off the machine, and supports and improves operator experience. Operators can monitor the full process including the cooling cycle, which can be altered to change the microstructure of parts to suit their needs.

Wayland Additive
www.waylandadditive.com