Development and experimental study of resistance seam additive manufacturing equipment

Novel resistance seam additive manufacturing (RSAM) equipment leveraging the resistance seam welding technology was explored to address the major limitations, including expensiveness, operational complexity, and thermal stresses, of conventional high-energy beam additive manufacturing techniques, such as those driven by lasers. This innovative solid-phase additive manufacturing technology is remarkable, as it ensures cost-effectiveness, reduced material consumption, operational simplicity, and minimized thermal input. Additionally, it effectively facilitates the production of tungsten carbide-incorporated AlCoCrFeNi_2.1 (WC-AlCoCrFeNi_2.1) cemented carbide using the AlCoCrFeNi_2.1 eutectic high-entropy alloy as a binder.

Thereafter, a series of orthogonal experiments were conducted to optimize the production of the WC-AlCoCrFeNi_2.1 hard alloys via RSAM. These experiments were aimed at analyzing the effects of various factors on the surface roughness and microhardness of the manufactured alloys.

Overall, the findings revealed that the optimal process parameters included a welding pressure of 0.4 MPa, a welding current of 5 kA, and a welding speed of 2 mm/s. Under these conditions, the resulting structure exhibited high stability and minimal defects, indicating that these parameters achieved high-quality results. Furthermore, the impacts of WC-powder particle size on the surface roughness and microhardness of the resistance additive samples were thoroughly investigated, and the findings revealed that reducing the WC-powder particle size significantly enhanced the surface finish. Specifically, when the WC-powder particle size was reduced to less than 5 μm, the surface of the produced alloy appeared notably smoother and more uniform. This enhanced surface quality was also accompanied by a significant increase in the average microhardness, which reached 1 911.2 HV. These results highlight the benefits of utilizing finer WC powders, particularly those with particle sizes of less than 5 μm, to achieve superior results in RSAM. Furthermore, a comparative analysis of the performance of WC-10%AlCoCrFeNi_2.1 hard alloy produced through resistance additive manufacturing and that of a traditional WC-10%Co hard alloy was performed based on critical mechanical properties, including hardness and elastic modulus. The results showed that the WC-10%AlCoCrFeNi_2.1 alloy exhibited significantly superior hardness than the WC-10%Co alloy, with notable improvements of 32.1%, 0.9%, and 28.6% in the xz, xy, and yz directions, respectively. In addition, the elastic modulus of the WC-10%AlCoCrFeNi_2.1 alloy was higher, with average increases of 14.2%, 3.7%, and 20.2% in the xz, xy, and yz directions, respectively.

These findings show the potential of the RSAM technology as a viable, advantageous approach for producing high-performance WC-based cemented carbides. Employing the AlCoCrFeNi_2.1 eutectic high-entropy alloy as the binder phase, this strategy achieved superior cost-effectiveness, environmental friendliness, and production efficiency compared with conventional manufacturing processes. Notably, the implications of this study transcend cemented carbides. The demonstrated adaptability of RSAM to various material systems, including ceramics, intermetallics, and multi-principal element alloys, offers new possibilities for fabricating advanced hard alloys and other high-performance materials. These achievements establish a robust foundation for subsequent studies on process optimization, multi-material fabrication, and industrial applications, with anticipated impacts on advancing additive manufacturing and material science.