Development of an infrared sensor-based system for interlayer temperature control in CMT-based wire arc additive manufacturing

:: Artigo completo

Abstract
Wire arc additive manufacturing is an emerging process that has garnered increasing attention from both industry and academia due to its capability to produce complex parts with minimal material waste and high industrial flexibility. However, to ensure that the fabricated parts are functionally applicable in industrial environments, several technological and scientific barriers must be overcome. In this context, sophisticated welding processes are commonly employed, with GMAW (Gas Metal Arc Welding), particularly its dynamic feeding variant CMT (Cold Metal Transfer), being the most utilized. Despite the sophistication of these processes, many challenges remain. One of the primary challenges in wire arc additive manufacturing is the "CAD to Part" relationship, which refers to the fidelity between the digital model (CAD) and the final produced part. Achieving this fidelity requires welding parameters to be aligned with the deposition path, thereby controlling bead geometry relative to the predetermined path. Among the parameters critical to controlling the deposition trajectory, interlayer temperature stands out due to its significant influence on both welding parameters and trajectory, as well as its impact on the mechanical and metallurgical properties of the final part. This work aims to present the development of an arc opening control system based on interpass temperature, using an infrared sensor integrated into an additive manufacturing robotic cell. To achieve this, a mapping of the GMAW-CMT welding process was initially conducted by depositing single weld beads on a plate at different temperatures to identify the threshold at which temperature significantly affects bead geometry. Subsequently, an IR sensor compatible with the function was selected, along with other necessary devices for system development (Arduino UNO R3 and Relay Module). The communication protocols required for integrating these devices with each other and with the robot controller (Yaskawa Motoman HP20D - DX100) were then identified. Finally, these devices were integrated using an algorithm developed in C#. To validate the system, a cylinder consisting of 180 layers was fabricated using the WAAM process. The system aimed to maintain consistent layer height by controlling the interpass temperature, varying the idle time. The results demonstrated that the interpass temperature has a significant influence on the weld bead geometry, the developed system provides accurate interpass temperature measurement and effective control of layer height through interpass temperature monitoring, thus achieving improved accuracy in the CAD to Part relationship.
Keywords: WAAM-CMT; Robotics; Automation; Welding; Industry 4.0.

Referência:
GALEAZZI, D.; SCHWEDERSKY, M. B.; SILVA, R. H. G.; SILVA, F. C.. Development of an infrared sensor-based system for interlayer temperature control in CMT-based wire arc additive manufacturing. 28th ABCM International Congress of Mechanical Engineering (COBEM), November 9-14, 2025. Curitiba, PR, Brazil