Effects of Thermal Camera Resolution on Feature Extraction in Selective Laser Melting

Selective Laser Melting (SLM) is a common additive manufacturing process which uses a laser energy source to fuse metal powder layer by layer. Engineering properties and microstructure are related to the part’s thermal history. It is important to measure the thermal history in-situ to qualify parts and provide the sensing which is necessary for process control. A common measurement tool for this purpose is a thermal camera that records the thermal emission of the part’s surface. This study investigates the effects of spatial sampling resolution of thermal cameras when monitoring the temperature in SLM processes. High-fidelity simulation of an SLM process is used to quantify the effects of the camera’s sampling in space. Next, the effect that spatial resolutions have on feature extraction, namely peak temperature and melt pool morphology, is investigated by applying feature extraction methodologies to the down-sampled simulation data. Finally, some methods of refining the down-sampled data are applied and their effects are discussed.