In wire-feed AM, a metal wire is used as supply material to build components – typically large ones of moderate complexity. Depending on the energy source used for deposition, wire-feed AM can be classified into three groups: wire and laser additive manufacturing (WLAM), electron beam freeform fabrication (EBF3) and wire and arc additive manufacturing (WAAM) [1, 2].
WAAM: Wire + Arc Additive Manufacturing
gas metal arc welding (GMAW) [1]
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plasma arc welding (PAW) [1]
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Wire and arc additive manufacturing (WAAM) is a popular wire-feed AM technology subdivided in three groups depending once more on the heat source and melting strategy [3-5]:
- gas metal arc welding (GMAW) ;
- gas tungsten arc welding (GTAW) ;
- or plasma arc welding (PAW).
GMAW is a process in which an electric arc forms between a consumable wire electrode and the work-piece. The wire is normally perpendicular to the substrate. GTAW and PAW use a non-consumable tungsten electrode to produce the melt track. Plasma arc generates relatively finer tracks compared to GTAW [6], usually causes less weld distortion and promote higher building rates [7].
A typical WAAM system (GMAW-based) comprises [8]:
- a computer interface – used to control the equipment and collect experimental results;
- a robot controller – used to coordinate robotic motions and welding processes.
- a programmable GMAW power source – to control the welding parameters;
- a large industrial robot – to move the welding torch;
- and monitoring equipment – to measure the bead/weld profile.
WLAM: Wire + Laser Additive Manufacturing
Wire laser AM [1]
Wire and laser additive manufacturing (WLAM) produces fully dense metal components using laser energy. The WLAM system normally consists of
- a laser;
- an automatic wire-feed system;
- a computer controlled worktable or a robot system;
- and some accessorial mechanisms (e.g. shielding gas, preheating or cooling system).
The metal wire is melted into a melt pool generated by the laser on the substrate to form a metallurgical bound [9].
The relative motion between the laser processing head and wire feeder relatively to the substrate is carried out by a robot arm or a computer controlled worktop.
EBF³: Electron beam freeform fabrication
(or Wire + Electron Beam Additive Manufacturing)
Electron beam freeform fabrication [10-13] (patented by NASA) builds complex, near-net-shape parts requiring substantially less raw material and finish machining than traditional manufacturing methods [14]. The process introduces metal wire into a molten pool that is created and sustained using a focused electron beam in a high vacuum environment. The electron beam couples effectively with any electrically conductive material, including highly reflective alloys such as aluminium and copper.
Take away
Wire-feed AM is a promising technology for producing larger components with moderate complexity, such as stiffened panels. It is more environmentally friendly and does not expose operators to powder hazards. Compared with the powder-based process, it has a much higher deposition rate.
The few challenges involved with using WAM include residual stress and distortion from excessive heat input, relatively poor part accuracy caused by the staircase effect and poor surface finish.
The few challenges involved with using WAM include residual stress and distortion from excessive heat input, relatively poor part accuracy caused by the staircase effect and poor surface finish.
References
[1] Donghong Ding, Zengxi Pan, Dominic Cuiuri, Huijun Li Wire-feed additive manufacturing of metal components:
technologies, developments and future interests Int J Adv Manuf Technol DOI 10.1007/s00170-015-7077-3
[2] Karunakaran K et al (2010) Low cost integration of additive and subtractive processes for hybrid layered manufacturing. Robot Comput Integr Manuf 26:490–499
[3] Ding J et al (2011) Thermo-mechanical analysis of wire and arc additive layer manufacturing process on large multi-layer parts. Comput Mater Sci 50:3315–3322
[4] Dickens P, et al (1992) Rapid prototyping using 3-D welding. In Proc. Solid Freeform Fabrication Symp: 280–290
[5] Spencer J et al (1998) Rapid prototyping of metal parts by three dimensional welding. Proc InstMech Eng B J EngManuf 212:175–182
[6] AiyitiWet al (2006) Investigation of the overlapping parameters of MPAW-based rapid prototyping. Rapid Prototyp J 12:165–172
[7] Mannion B, Heinzman J (1999) Plasma arc welding brings better control. Tooling Prod 5:29–30
[8] Ding D et al (2014) A tool-path generation strategy for wire and arc additive manufacturing. Int J Adv Manuf Technol 73:173–183
[9] Heralic A (2012) Monitoring and control of robotized laser metal wire deposition. Doctoral thesis, Chalmers University of Technology
[10] Zalameda JN, et al. (2013) Thermal imaging for assessment of electron beam free form fabrication (EBF3) additive manufacturing deposits. SPIE Defense, Security, and Sensing, International Society for Optics and Photonics
[11] Taminger KMB et al (2006) Electron beam freeform fabrication for cost effective near-net shape manufacturing. NATO AVT 139:16–1
[12] Rännar LE et al (2007) Efficient cooling with tool inserts manufactured by electron beam melting. Rapid Prototyp J 13: 128–135
[13] Wanjara P et al (2007) Electron beam freeforming of stainless steel using solid wire feed. Mater Des 28:2278–2286
[14] Taminger KMB et al (2003) Electron beam freeform fabrication: a rapid metal deposition process. In: Proceedings of third annual automotive composites conference, Society of Plastic Engineers, Troy, MI; 9–10
[15] DuPont J et al (1995) Thermal efficiency of arc welding processes. Weld J Incl Weld Res Suppl 74:406s
[16] Stenbacka N, et al (2012) Review of Arc Efficiency Values for Gas Tungsten Arc Welding. IIW Commission IV-XII-SG212, Intermediate Meeting, BAM, Berlin, Germany, 18–20 April
[17] Rännar LE et al (2007) Efficient cooling with tool inserts manufactured by electron beam melting. Rapid Prototyp J 13: 128–135
[18] S. W. Williams, F. Martina*, A. C. Addison, J. Ding, G. Pardal and P. Colegrove, Wire þ Arc Additive Manufacturing Materials Science and Technology DOI 10.1179/1743284715Y.0000000073
[1] Donghong Ding, Zengxi Pan, Dominic Cuiuri, Huijun Li Wire-feed additive manufacturing of metal components:
technologies, developments and future interests Int J Adv Manuf Technol DOI 10.1007/s00170-015-7077-3
[2] Karunakaran K et al (2010) Low cost integration of additive and subtractive processes for hybrid layered manufacturing. Robot Comput Integr Manuf 26:490–499
[3] Ding J et al (2011) Thermo-mechanical analysis of wire and arc additive layer manufacturing process on large multi-layer parts. Comput Mater Sci 50:3315–3322
[4] Dickens P, et al (1992) Rapid prototyping using 3-D welding. In Proc. Solid Freeform Fabrication Symp: 280–290
[5] Spencer J et al (1998) Rapid prototyping of metal parts by three dimensional welding. Proc InstMech Eng B J EngManuf 212:175–182
[6] AiyitiWet al (2006) Investigation of the overlapping parameters of MPAW-based rapid prototyping. Rapid Prototyp J 12:165–172
[7] Mannion B, Heinzman J (1999) Plasma arc welding brings better control. Tooling Prod 5:29–30
[8] Ding D et al (2014) A tool-path generation strategy for wire and arc additive manufacturing. Int J Adv Manuf Technol 73:173–183
[9] Heralic A (2012) Monitoring and control of robotized laser metal wire deposition. Doctoral thesis, Chalmers University of Technology
[10] Zalameda JN, et al. (2013) Thermal imaging for assessment of electron beam free form fabrication (EBF3) additive manufacturing deposits. SPIE Defense, Security, and Sensing, International Society for Optics and Photonics
[11] Taminger KMB et al (2006) Electron beam freeform fabrication for cost effective near-net shape manufacturing. NATO AVT 139:16–1
[12] Rännar LE et al (2007) Efficient cooling with tool inserts manufactured by electron beam melting. Rapid Prototyp J 13: 128–135
[13] Wanjara P et al (2007) Electron beam freeforming of stainless steel using solid wire feed. Mater Des 28:2278–2286
[14] Taminger KMB et al (2003) Electron beam freeform fabrication: a rapid metal deposition process. In: Proceedings of third annual automotive composites conference, Society of Plastic Engineers, Troy, MI; 9–10
[15] DuPont J et al (1995) Thermal efficiency of arc welding processes. Weld J Incl Weld Res Suppl 74:406s
[16] Stenbacka N, et al (2012) Review of Arc Efficiency Values for Gas Tungsten Arc Welding. IIW Commission IV-XII-SG212, Intermediate Meeting, BAM, Berlin, Germany, 18–20 April
[17] Rännar LE et al (2007) Efficient cooling with tool inserts manufactured by electron beam melting. Rapid Prototyp J 13: 128–135
[18] S. W. Williams, F. Martina*, A. C. Addison, J. Ding, G. Pardal and P. Colegrove, Wire þ Arc Additive Manufacturing Materials Science and Technology DOI 10.1179/1743284715Y.0000000073