Real-time measurement of temperature and volume of the weld pool in wire-arc additive manufacturing

Abstract The quality of the material deposition and contour accuracy produced by WAAM (Wire Arc Additive Manufacturing) depends on process parameters such as the temperature and the volume of the weld pool. The control of the welding process can be substantially improved by obtaining real-time signals of the weld-pool temperature and volume. In this paper, we present a new optical sensor that can measure the quantities through the welding arc. We have developed a ratio pyrometer with narrowband filters that suppresses the radiation from the plasma. We present our new sensor in this paper and demonstrate its capability to measure the weld-pool temperature pyrometrically and the weld-pool area by digital image processing as a real-time signal through the arc. In addition, we estimate the weld-pool volume from its area and the known material inflow.