Wire arc additive manufacturing (WAAM) is a crucial technique in the fabrication of 3D metallic structures. It is increasingly being used worldwide to reduce cost and time. Generally, AM technology is used to overcome the limitations of traditional subtractive manufacturing (SM) for fabricating large-scale components with lower buy-to-fly ratios. It became interesting for scientists and manufacturers due to its ability to produce fully dense metal parts and large near-net-shape products. WAAM is mostly used in modern industries, like aerospace industry. There are three heat sources commonly used in WAAM: metal inert gas welding (MIG), tungsten inert gas welding (TIG), and plasma arc welding (PAW). MIG is easier and more convenient than TIG and PAW because it uses a continuous wire spool with the welding torch. Unlike MIG, tungsten inert gas welding (TIG) and plasma arc welding (PAW) need an external wire feed machine to supply the additive materials. WAAM is gaining popularity in the fabrication of 3D metal components, but the process is hard to control due to its inherent residual stress and distortion, which are generated by the high thermal input from its heat sources. Distortion and residual stress are always a challenge for WAAM because they can affect the component’s geometric accuracy and drastically degrade the mechanical properties of the components.

1. WIRE ARC ADDITIVE
MANUFACTURING

2. WIRE ARC ADDITIVE MANUFACTURING
2

3. CONTENT
• Introduction
• Process
• Process parameters
• Classification
• Benefits
• Quality improvement
• Applications
• Conclusion
• Reference
3

4. INTRODUCTION
• Wire Arc Additive Manufacturing - WAAM
• Origin of the process can be traced back to the 1925s
• Crossover between Fused Deposition Modelling (FDM) and welding
process
• Promising fabrication process for various engineering metals
• Widely used in Defence Applications
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5. WAAM SYSTEM DESIGN CONCEPTS
CAD
Modelling
3D Slicing
Path
Planning
Process
Control
Fabrication
Process
Process
Monitoring
Bead
Modelling
Path Re-
planning
Process
Control
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6. PROCESS
• Wire as feedstock
• Electric Arc as heat source
• Adds material layer by layer
• Motion can be provided either by
1. Robotic System
2. Computer Numerical Controlled Gantries
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7. PROCESS(cont.)
Figure 1. Experimental Setup
(Source: A. Horgar et al., 2018)
Figure 2. Deposited Layers
(Source: A. Horgar et al., 2018)
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8. PROCESS PARAMETERS
• Wire feed speed(WFS)
Rate at which wire is fed through the torch
• Travel speed(TS)
Speed of the bead relative to the surface and typically it is
controlled by the speed of the torch
• Current, Voltage
Automatically adjusted depending on the WFS to produce a
suitable arc of the correct energy and length for welding
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9. ENERGY SOURCE
Gas Metal Arc
Welding (GMAW)-
based
Gas Tungsten Arc
Welding (GTAW)-
based
Plasma Arc
Welding (PAW)-
based
CLASSIFICATION
9

10. GMAW-based
• Commonly used process
• Consumable wire electrode
• Typical deposition rate: 3-4kg/hour
• Poor arc stability
• Spatter
• Aluminium and steel
• Arc wandering when Titanium is used
10

11. GTAW-based
• Non-consumable electrode
• Separate wire feed process
• Typical deposition rate: 1-2kg/hour
• Wire and torch rotation are needed
• Complicated Robot Programming
• Titanium
11

12. PAW-based
• Non-consumable electrode
• Separate wire feed process
• Typical deposition rate: 2-4kg/hour
• Wire and torch rotation are needed
• Complicated Robot Programming
• Titanium
12

13. METALS USED
• Titanium Alloys
• Aluminium Alloys and Steel
• Nickel-based super alloys
• Magnesium Alloys
• Bimetals
13

14. BENEFITS
• Capital Cost
• Open Architecture
• Part Size
• Deposition Rate
• Reduced post-machining time
• Complex geometries
14

15. COMMON DEFECTS
• Deformation and Residual Stress
• Porosity
• Crack
• Delamination
• Oxidation
• Surface finish
15

16. QUALITY IMPROVEMENT
Post-process
treatment
Heat Treatments Work Hardening
Interpass Gas
Cooling
16

17. POST-PROCESS TREATMENTS
• Ageing
• Solution Treatments
• Combinations
• Peening
• Ultrasonic
• Cold rolling
• Cooling Gas
17

18. APPLICATIONS
• Aerospace
• Automotive
• Marine
• Architecture
• Tools
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19. PRODUCTS
Figure 3. World’s first 3D printed Ship’s propeller
(Source: Google Images)
Figure 4. WAAM to 3D print Stiffeners directly on
Airplane Fuselage Panels
(Source: Google Images)
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20. CONCLUSION
• Suitable to the manufacturing of medium to large scale components
• WAAM is a candidate to replace the current method of manufacturing
aerospace components from billets or forgings
• Substantial reductions in material waste and lead time
• Current lack of a commercially available platform limits the industrial
evaluation and adoption
• It is an inherently non-equilibrium thermal process
• The WAAM process will see a wide application in the future years
20

21. REFERENCE
• A. Horgar, H. Fostervoll, B. Nyhus, X. Ren, M. Eriksson, O.M.
Akselsena (2018). Additive manufacturing using WAAM with AA5183
wire, Journal of Materials Processing Tech. 259: 68-74
• A. Queguineur, G. Ruckert, F. Cortial, J. Y. Hascoet (2017). Evaluation
of wire arc additive manufacturing for large-sized components in
naval applications, Welding in the World 62: 259-266
• Bintao Wua, Zengxi Pana, Donghong Ding, Dominic Cuiuria, Huijun
Lia, Jing Xuc, John Norrisha (2018). A review of the wire arc additive
manufacturing of metals: properties, defects and quality
improvement, Journal of Manufacturing Processes 35: 127-139
21

22. REFERENCE(cont.)
• Busachi A., Erkoyuncu J., Colegrove P., Martina F., Ding J. (2015).
Designing a WAAM Based Manufacturing System for Defence
Applications, Procedia CIRP 37: 48-53
• Han S., Zielewski M., Holguin D. M., Parra M. M., Kim N. (2018).
Optimization of AZ91D Process and Corrosion Resistance Using Wire
Arc Additive Manufacturing, Applied Sciences 8: 1306
• S. W. Williams, F. Martina, A. C. Addison, J. Ding, G. Pardal, P.
Colegrove (2016). Wire + Arc Additive Manufacturing, Materials
Science and Technology, 32:7, 641-647
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“IT IS OUR FUTURE!”
Jose Cocovi Mold Line Manager at Michelin