The laser-based additive manufacturing processes (LAM) becomes more and more frequently used in industrial environment due to the known benefits regarding geometrical complexity, customizability and economization of material input. However, in many cases every part must be tested non-destructively. Online process monitoring should prevent cost-expensive CT analysis and provide detailed documentation for every part. A novel process monitoring system based on a two-channel-pyrometer camera is used to observe the temperature field in the commonly used LAM processes laser metal deposition (LMD) and laser powder bed fusion (LPBF). Different indicators from the temperature field in the process zone are investigated regarding their ability to characterize the process quality. The measured melt pool geometry is compared to metallographic measurements to demonstrate the accuracy of the measurement. The deviation between the measured melt pool width of the monitoring system and the width of the metallographic cross section is 4% in LMD and 5% in LPBF.
- Describe the relation between process state, temperature field and resulting part quality
- Demonstrate the high precision in temperature and melt pool geometry measurement with high speed in different laser based additive manufacturing processes like LMD or SLM
- Show first experimental results of closed loop control in laser-based additive manufacturing processes