Infrared Camera Supports Real-Time Process Control for Laser Metal Deposition and Cladding

The need for in-process monitoring of metal 3D printing processes is well-recognized but integration of cameras, sensors and systems to make this possible can be a hurdle. Madrid-based New Infrared Technologies (NIT) has developed a compact system for monitoring melt pools in directed energy deposition (DED) or laser metal deposition (LMD) 3D printing and laser cladding. The company’s Clamir system uses a high-speed infrared camera to continuously measure the melt pool in real time, and adjust the laser power to maintain the integrity of the print.

According to NIT business development manager Guillermo Guarnizo, the Clamir system’s objective is to maintain a melt pool that is “as stable as possible” by achieving a consistent meltpool width. Just that measurement alone is enough data for the closed-loop system to effectively alter the laser power in real time to keep the melt pool within established limits.  

This is a change from how DED typically operates, with the laser under constant power. Over the course of the build, a consistent power setting can cause regions of the part to overheat and excess material to build up, leading to poor surface finish. Parts can end up deforming or needing additional postprocessing work to correct these issues. In cladding operations, constant laser power can even degrade the base material and prevent good adherence. Variable laser power based on real-time process monitoring can correct for these issues in situ, leading to better part quality and consistency.

Applying the Clamir system demands only a minimal hardware requirement. The solution consists of a camera, processor and control unit within a single housing that is mounted to the 3D printer’s laser head. As material is deposited, the middle wavelength infrared (MWIR) camera captures images of the melt pool at a rate of 1,000 frames per second. The width of the melt pool is measured with each image and compared to a value set by the user or automatically determined by the system; if the melt pool is found to be wider than expected, the Clamir control will reduce the laser power to prevent material overflow and heat deformation.

“It allows for printing of finer structures without building up excess material,” Guarnizo says, which is a benefit to downstream processes as well as 3D printing. According to the company, the use of the Clamir system helps to reduce defective parts and increase productivity, while also reducing CO₂ emissions and saving energy.

See a side-by-side comparison of LMD with and without Clamir in this video, provided by Trumpf: 

NIT won the Industrial & Enabling Tech category of the European Commission’s Innovation Radar contest in 2018 for Clamir and I3LasWeld, a similar platform for real-time classification of laser welding defects. Since then, New Infrared Technologies has worked with a number of equipment providers including Trumpf, Laserline and Precitec to incorporate Clamir into their equipment; the solution is also available to individual users. Most current customers are based in Europe, but the company is seeking to expand its presence in North America in 2023.