Wire Arc Additive Manufacturing (WAAM) Explained

Curious about WAAM and when to opt for this technology vs LPBF? This article gives you the complete overview.

Welcome to the world of Wire Arc Additive Manufacturing, or WAAM for short. This 3D printing technology is gaining traction in manufacturing, and for good reason. The process is fast, accurate, and capable of precisely producing large objects.

How large, you ask? This technology has been used for everything from enormous crane hooks to entire bridges in Amsterdam. However, WAAM is also helpful on a much smaller scale.

In this article, we will explore the WAAM process in detail, including the different types of WAAM, materials used, and steps involved. You'll also learn the advantages and drawbacks of WAAM and its applications in various industries. One important section highlights when to use WAAM vs Laser Powder Bed Fusion for your additive manufacturing project.

What is WAAM?

WAAM process is similar to traditional welding, where the metal wire is melted and added to the base material to form a joint.

However, WAAM is automated and controlled by a computer program and performed by a robot arm to build complex geometries. This manufacturing technology uses an electric arc to melt a metal wire, which is then deposited layer by layer to create a 3D object.

Materials used in WAAM

The materials used in WAAM depend on the application and the properties required for the final object. Some of the commonly used materials in WAAM include:

Steel: Steel is a popular choice for WAAM due to its strength and durability. It is commonly used in the aerospace and automotive industries to produce structural components.

Titanium: Titanium is a lightweight, strong, and corrosion-resistant metal often used in the aerospace and biomedical industries.

Aluminum: Aluminum is a light and strong material for producing components that require high strength and durability.

Copper: Copper is used in the electrical and electronics industry to produce parts requiring good electrical conductivity.

In addition to these metals, WAAM can also use metal alloys and composites – such as nickel alloys - which can provide unique properties such as high strength-to-weight ratios and corrosion resistance.

This 3D-printed bridge in Amsterdam was made with stainless steel. Amsterdam: 3D Printed Bridge by harry_nl is licensed under CC BY-NC-SA 2.0.

Applications of WAAM

WAAM has various applications in various industries. Some of the applications of WAAM include:

Aerospace: WAAM is used in the aerospace industry to produce structural components such as wings, fuselage sections, and engine parts. WAAM can produce large, complex components with high precision, which can reduce the need for assembly and welding. WAAM can also repair and refurbish aircraft components, saving time and costs.

Automotive: WAAM is used in the automotive industry to produce engine parts, exhaust systems, and other components that require high strength and durability. BMW is a believer in the technology, having invested in a WAAM machine for its Additive Manufacturing Campus in Munich.

Energy: WAAM has helped prevent supply chain struggles by making replacement parts for oil refineries. The technology can also produce components for wind turbines.

Art: With WAAM being capable of massive parts, a number of artists have used this technology for eye-catching installations.

Automotive: WAAM is used in the automotive industry to produce engine parts, exhaust systems, and other components that require high strength and durability. BMW recently invested in a WAAM machine.

Other Industries: The energy, defense, and construction industries also use WAAM for various applications, such as ships. Recently, the US Navy invested in WAAM technology to create components for its submarines.

Steps of WAAM

The WAAM process involves several steps, which are as follows:

1. Design: The first step in the WAAM process is the design of the 3D object. The object is designed using computer-aided design (CAD) software, which generates a digital part model. The digital model is then converted into a machine-readable format for the WAAM system. The part will be sliced in many layers and a toolpath for the robot arm will be created.

If you’re using the MakerVerse platform, this is the only step you need to worry about – we take care of the rest with our fully-vetted supply chain to ensure the quality of your part.

2. Preparation: Next is preparing the base material and the wire. The base material is cleaned and prepared for welding, and the wire is loaded into the wire feeder system. The welding torch is also prepared, while the robot or CNC machine is programmed to follow the pre-determined path.

3. Printing: Now, production can begin. The welding torch is moved along the pre-determined path, and an electric arc melts the wire to fuse it to the base material. The process is repeated layer by layer until the final object is complete.

4. Post-Processing: We're not done yet. The object is removed from the WAAM system and undergoes various post-processing steps, such as cleaning, heat treatment, and finishing. The post-processing steps depend on the application and the desired properties of the final object.

Advantages and Disadvantages of WAAM

WAAM offers several advantages over traditional manufacturing methods, which include:

1. Cost-Effective: WAAM is a cost-effective method to producefor producing large, complex objects. WAAM can reduce the cost of material and labor and the need for assembly and manual welding.

2. Time-Saving: WAAM can save time in the production process, producing complex objects in a single step. WAAM can also reduce the time required for post-processing, as it can create objects with near-net shapes.

3. Customizable: WAAM can produce customized objects with high precision and accuracy. WAAM can also produce objects with specific properties such as strength, corrosion resistance, and electrical conductivity.

4. Environmentally Friendly: WAAM can reduce waste and energy consumption. WAAM can also use recycled materials, which can reduce the environmental impact of manufacturing.

Despite its advantages, WAAM has some drawbacks, which include:

1. Accuracy: Wide tolerances and the need for final machining to get functional surfaces

2. Limited Material Options: WAAM can only use materials that are compatible with the welding process, limiting the range of materials that can be used.

3. Surface Roughness: Parts have a rough surface finish, which may require additional post-processing steps such as polishing and sanding.

4. Skill Requirements: WAAM requires skilled operators who are trained in welding and programming. The process is complex and requires a high level of expertise to ensure the quality and accuracy of the final object. Fortunately, MakerVerse possesses the expertise to ensure the industrial quality of your part.

When to Use Wire Arc Additive Manufacturing vs. Laser Powder Bed Fusion

The most established metal additive manufacturing technologies is Laser Powder Bed Fusion. This technology uses an inert gas atmosphere and a laser whose thermal energy is used to melt metal powder which is stored in a powder bed. As this happens repetitively layer by layer, the material is fused together.

There are some clear cases when to use one technology over the other:

Oversized parts: WAAM

WAAM is capable of enormous parts. Earlier, we mentioned how an entire bridge was made with this technology. Through MakerVerse, LPBF parts of up to 65 cm is possible. While that’s enough for many applications, WAAM is the technology of choice for bigger parts.

Precision and Accuracy: LPBF

WAAM might be able to go bigger, but LPBF is capable of higher precision and accuracy. Depending on the materials, accuracy of +/- 0.3 mm is achievable with a minimum wall thickness of 0.8 mm. WAAM’s minimum wall thickness is 4 mm with a resolution of 1 mm.

Cost: WAAM (Usually)

The cost depends on the application and production requirements. However, WAAM can be cheaper due to its ability to print at high deposition rates. For parts requiring the most precision and accuracy, LPBF may be more cost-effective. In any case, it's important to carefully evaluate the benefits and drawbacks of each process and determine which is most suitable for the specific project at hand.

Surface Finish: LPBF

LPBF produces parts with a high-quality surface finishes, which helps cut down on post-processing.

A variety of parts made with LPBF.

Getting Started with WAAM

Wire Arc Additive Manufacturing (WAAM) is a cost-effective method for the production of large, complex objects. WAAM can produce customized objects decent precision and accuracy, making it a valuable method for a wide range of applications.

WAAM opens up new possibilities for producing large, complex objects. We expect that the technology will continue evolving, making it even more widely adopted.