Model-based temperature offset compensation for additive manufacturing by directed energy deposition

Laser based directed energy deposition (DED), also known as laser metal deposition or laser cladding, is an additive manufacturing technology for building 3D freeform parts. Reliable temperature measurements are of obvious interest and importance for the control of these processes. We propose a model-based method for the correction of temperature measurements from an imperfectly aligned sensor, which is a pyrometer in our process. We show that the proposed method can improve the reliability of the pyrometer-based temperature measurements even if the pyrometer is carefully aligned and calibrated according to industrial standards. We apply the proposed method to a powder-based directed energy deposition process. Due to its simplicity, the proposed method can easily be adapted to other additive manufacturing process types. Copyright (C) 2020 The Authors.