The precise recording of temperatures is crucial for the quality of 3D-printed components. Researchers at Carnegie Mellon University want to set new standards here with a groundbreaking technique.
Using a commercially available color camera with a Bayer sensor, the team succeeded in analyzing in detail the physics of the melt pool during the laser powder bed process. By measuring specific color values and their relationship to each other, they can precisely calculate the temperature.
This ratiometric approach overcomes limitations of conventional infrared measurement technology, which often has problems with surface properties and visibility factors. According to the scientists, the method’s high frame rate and resolution provide a new view of complex processes.
In addition to accurate temperature measurements, the method also provides new parameters for simulating the 3D printing process. Based on the distribution of peak temperatures in the melt pool, material evaporation and microstructure of the final component can be studied.
A major advantage of the approach is its independence from the emissivity and transmissivity of the metal vapor. These material parameters no longer have to be determined at great expense.
The researchers have already been able to achieve promising results with the camera technique in recording temperature curves. They see great potential to transfer their method to other 3D printing processes and thus improve the quality and efficiency of additive manufacturing in aviation or mechanical engineering.
The team published details of the novel single-camera method in an article entitled “High-resolution melt pool thermal imaging for metals additive manufacturing using the two-color method with a color camera” in the journal Additive Manufacturing.