Possibilities of non-contact temperature measurement in additive direct metal laser sintering technology

The DMLS (Direct metal laser sintering) additive technology is very suitable for the production of metal prototype parts and especially for the production of parts with complicated geometry, which is very difficult or nearly impossible to produce in another way. Temperature monitoring during the 3D printing process is very important to maintain the quality and optimize the printing process. This can reveal areas with a non-standard printing process that can present potential defects and the consequent risk of component failure during operation. The non-contact method of temperature measurement is used for the analysis of temperatures during the printing by the DMLS method. The evaluation of effective emissivity of the printing powder material and effective transmittance of the IR window for the used infrared cameras are the necessary steps. Temperature measurement during the printing process is performed using two infrared cameras with different technical parameters. The evaluation of infrared camera measurements is performed using standard and HoldMax thermograms, and time courses of the temperature in selected areas of the printed part. The presented results show the possibilities of individual infrared cameras for the analysis of the printing process. The utilized infrared cameras complement each other in a suitable way and together they provide essential information about the course of the printing process.