Wire and Arc Additive Manufacturing (WAAM) presents a compelling alternative to the widely promoted powder-based additive manufacturing methods. While powder-based processes have gained attention for producing high-precision components, WAAM offers significant advantages in speed, cost-effectiveness, and the ability to produce larger, heavier components, making it particularly suitable for industries like aerospace and maritime.
This analysis highlights the economic and operational benefits of WAAM over powder-based methods. WAAM equipment is significantly more affordable, with a setup cost of around $120,000 compared to the $750,000 typically required for powder deposition systems. Consumables are also more economical, with wire electrodes available at a fraction of the cost of metal powders. Moreover, WAAM's deposition rate, reaching up to 10 kg per hour, far outpaces the slower rates of powder-based processes.
Both methods require protection against oxidation, but WAAM’s use of welding torches and flexible enclosures provides a cost-effective solution compared to the expensive metal enclosures needed for powder methods. The case study concludes that while powder-based processes are ideal for small, delicate parts, WAAM is the superior choice for manufacturing large-scale components quickly and cost-effectively.
Essential products like Flexible Welding Enclosures® and PurgEye® Weld Purge Monitors® enhance the WAAM process, ensuring a controlled environment and preventing oxidation during metal deposition. As WAAM continues to develop, it is poised to become the preferred method for large-scale additive manufacturing.
Cost of Equipment
In additive manufacturing, a popular misconception persists that powder-based methods are superior to wire-based alternatives. This belief has primarily been fuelled by aggressive marketing and focus on the powder method’s success in producing high-precision components, such as body implants. However, regarding speed, cost-effectiveness, and the ability to make more significant components, Wire and Arc Additive Manufacturing (WAAM) is the clear winner.
The cost of equipment is a significant factor in any manufacturing process. Powder deposition technology requires a substantial financial investment. A typical system includes a metal enclosure housing all operating systems, including a laser or electron beam heat source, computer numerical control (CNC) equipment, and powder dispensing mechanisms. The total cost for such a setup can reach approximately $750,000.
In contrast, wire deposition is far more economical. It uses standard arc welding equipment and a 5-axis articulated robot, bringing the total cost to around $120,000. This significant difference makes WAAM a more accessible option for industries looking to implement additive manufacturing without breaking the bank.
Cost of Consumables
The cost of consumables further highlights the economic advantage of wire-based additive manufacturing. Only a limited number of metallic alloy systems are available for powder-based processes, with materials like Ti-6Al-4V, some stainless steels, Inconel 625/718, and Al-Si-10Mg being the most common. The cost of these powders can be prohibitive, with stainless steel powders priced around $400 per kilogram.
On the other hand, the wire-based process benefits from the widespread availability of wire electrodes used in traditional fusion welding. These wires are produced in large quantities, keeping costs low—stainless steel filler wire, for example, is readily available for about $30 per kilogram. This cost advantage makes WAAM more economical and versatile, given the broader range of materials available.
Deposition Rate
When it comes to deposition rates, WAAM again outperforms powder-based methods. Powder deposition rates are notoriously slow, averaging around 0.1 kg per hour. While technological advancements may improve these rates over time, they limit the process’s applicability, especially for more significant components.
In comparison, the wire arc process can achieve deposition rates of up to 10 kg per hour across a wide range of metal alloys. This high rate of deposition makes WAAM particularly suitable for quickly and efficiently producing larger, heavier parts.
Protection of the Deposit
Both powder and wire additive manufacturing processes require protecting molten metal from oxidation and contamination. In powder-based methods, this protection is typically achieved by conducting the process within a metal enclosure that can be purged with inert gas. The electron beam technique, used in some powder methods, is performed in a vacuum, eliminating the need for additional shielding.
WAAM, however, relies on the welding torch to provide a protective flow of inert gas, such as argon. To enhance protection, flexible enclosures can contain the torch and manipulation system, ensuring a controlled environment throughout the deposition process. These flexible enclosures are a cost-effective solution compared to the metal enclosures required for powder methods.
Conclusion
While powder-based additive manufacturing processes have their place in producing small, delicate, and exact components, Wire and Arc Additive Manufacturing (WAAM) offers distinct advantages for more significant, heavier parts. WAAM is more cost-effective in terms of equipment and consumables and provides a much faster deposition rate. For industries such as maritime and aerospace, where large-scale components are standard, WAAM is the superior choice.
The use of flexible enclosures and advanced oxygen monitoring systems, like the PurgEye® Weld Purge Monitor®, further enhances the process by ensuring a clean, controlled environment during deposition. As WAAM continues to evolve, it is set to become the go-to method for large-scale additive manufacturing applications.
