Development and application of arc additive manufacturing experimental platform integrating GTAW and GMAW

Wire arc additive manufacturing (WAAM) is a pivotal technology within the “Made in China 2025” strategy. Compared with laser/electron beam-based additive manufacturing methods, WAAM is characterized by superior deposition efficiency and material utilization. Despite its industrial potential in manufacturing medium-to-large metal components, widespread adoption in academic research and small-to-medium enterprises is currently constrained by the prohibitive costs and closed-source architectures of commercial systems. Conversely, existing low-cost open-source platforms often fail to meet necessary standards for motion control precision, forming stability, and system extensibility, particularly regarding the integration of multiple welding processes. To bridge this gap and provide a robust tool for process validation and engineering education, this study employed an open-source control architecture to design and construct a cost-effective, desktop-level experimental platform integrating gas tungsten arc welding (GTAW) and gas metal arc welding (GMAW) processes.

The experimental platform was developed using a modular, open-source architecture featuring a moving gantry three-axis mechanical structure. Thereafter, GTAW and GMAW torches were integrated onto the Z-axis to optimize cost and spatial efficiency. High-torque 86 × 80 stepper motors (4.5 N·m) powered by high-subdivision drivers and ball screw transmission were selected to ensure positioning precision and structural rigidity. The control system adopts a master–slave configuration, where a personal computer generates G-code trajectories and an Arduino Uno running Grbl firmware executes real-time motion control, thereby synchronizing arc ignition/extinction (M8/M9 commands) and gas supply via relay modules. To mitigate oxidation during local shielding, a novel dual-path gas system integrating standard torch delivery with a micropore supply embedded within the base fixture was designed. Single-bead deposition experiments using Q345B steel substrates and an ER50-6 wire were conducted to systematically investigate the effects of travel speed (0.24–0.48 m/min) and wire feed speed (5.0–7.0 m/min) on bead geometry and forming quality.

Experimental analysis revealed a distinct linear correlation between the process parameters and bead geometry. Specifically, increasing the wire feed speed from 5.0 to 7.0 m/min significantly expanded the bead from 3.889 to 6.115 mm and increased reinforcement from 1.252 to 4.029 mm, driven by the enhanced deposition rate. However, excessive wire feed speed (7.0 m/min) compromised stability, causing severe spatter and undercutting, while excessive travel speed induced snake-like defects and discontinuity. Travel and wire feed speeds of 0.36 and 6.0 m/min, respectively, were identified as the optimal parameter combinations. This setting achieved a dilution rate of 5%–15%, facilitating the fabrication of complex structures such as single-bead multilayer walls without macroscopic defects. Microstructural analysis confirmed the presence of a matrix of proeutectoid ferrite, acicular ferrite, bainite, and pearlite. Notably, regional variations were also observed: the bottom zone featured coarse grains due to substrate quenching, the middle zone formed interlaced acicular ferrite under moderate cooling, and the top zone contained side-plate ferrite and pearlite induced by solute enrichment.

The developed platform successfully integrated GTAW and GMAW processes within a low-cost, open-source framework, achieving a balance between cost-effectiveness and control precision. By enabling the fabrication of well-formed metal components with excellent microstructures, the platform demonstrated its viability as a versatile and economical solution for WAAM process exploration, educational demonstrations, and fundamental research in universities and research institutions.