By: Dr. Richard Grylls, LENS Product Manager
It’s as simple as melting metal powder with a laser! Yet to achieve repeatable results with a LENS metal 3D printer for the highest performance applications, you need to monitor, understand, control and record the key process variables with high precision and reliability. Simple applications might be satisfied by an operator checking laser power once a day, for example, but for a critical application this isn’t sufficient. Not only do primary process variables, such as laser power, need to be tracked, but secondary variables, such as melt-pool temperature, can also be important for high-performance applications. Optomec has been at the forefront of developments in this area for fifteen years, and systems such as the closed-loop control Melt-Pool Sensor have been in use almost that long. For the last five years, Optomec and Stratonics Inc. have partnered together to adapt Stratonics ThermaViz Thermal Imaging system for use with the LENS system. The ThermaViz system is mounted to look straight down at the melt-pool through the focusing lens, so it gives a highly magnified view of the melt-pool, and is able to give a temperature map of the melt pool down to less than 20 microns resolution. Until 2012, this system was only available on the LENS MR-7 system, but in 2012, thanks to a redesign of both the LENS camera box, and the ThermaViz unit itself, we were able to start offering it on the LENS 850R as well. Additionally, software and hardware improvements now allow the ThermaViz system to measure temperatures down to ~600C – no mean feat considering the very low infra-red radiation intensity at that temperature. Stratonics and Optomec are continuing to rapidly innovate in this area – look out for more new product offerings in 2013, including options for a wider field of view, and more innovative software features!