Monitoring of Single-Track Degradation in the Process of Selective Laser Melting

Selective laser melting machines provide the optimal working parameters for manufacturing during the process. However, the laser interaction with metal powder is an unstable. The gasdynamic flows make powder particles move and escape from the melt pool. This phenomenon leads to an irregular distribution of the material volume being remelted. Since the energy is constant during the process, single-tracks with different geometry are appeared and their superposition forms the 3D-object. To detect the process abnormality of stable track formation there was developed a control system based on morphological analysis of thermal image obtained by IR-camera. The temperature field distribution along the image matrix’s row with the maximum temperature was used as influencing factor on stable track formation. Roughness was reduced from 39.9 to 6.6 µm by using control system with the same process parameters. The obtained results can be applied in industrial SLM machines with the integrated active control system.