Wire Arc Additive Manufacturing (WAAM) is attracting significant attention in industry and academia due to its ability to capture the benefits of additive manufacturing for production of large components of medium geometric complexity. Uniquely, WAAM combines the use of wire and electric arc as a fusion source to build components in a layer-by-layer approach, both of which can offer significant cost savings compared to powder and alternative fusion sources, such as laser and electron beam, respectively. Meanwhile, a high deposition rate, key for producing such components, is provided, whilst also allowing significant material savings compared to conventional manufacturing processes. However, high quality production in a wide range of materials is limited by the elevated levels of heat input which causes a number of materials processing challenges in WAAM. The materials processing challenges are fully identified in this paper to include the development of high residual stresses, undesirable microstructures, and solute segregation and phase transformations at solidification. The thermal profile during the build poses another challenge leading to heterogeneous and anisotropic material properties. This paper outlines how the materials processing challenges may be addressed in WAAM by implementation of quality improving ancillary processes. The primary WAAM process selections and ancillary processes are classified by the authors and a comprehensive review of their application conducted. Strategies by which the ancillary processes can enhance the quality of WAAM parts are presented. The efficacy and suitability of these strategies for versatile and cost effective WAAM production are discussed and a future vision of WAAM process developments provided.

https://purehost.bath.ac.uk/ws/files/183236429/StrategiesAndProcessesForHighQualityWireArcAdditiveManufacturing_Manuscript.pdf

Invited review article: Strategies and processes for high quality wire arc additive manufacturing

https://profdoc.um.ac.ir/articles/a/1055852.pdf

Welding processes for wear resistant overlays

Wire and arc additive manufacturing : Opportunities and challenges to control the quality and accuracy of manufactured parts

The invention relates to a welding device (1) or an electricity supply (2) comprising a control device (4) which is preferably formed by a microprocessor control device having a memory unit, a power component (3), in particular an inverted electricity supply and additional components such as a welding torch (10), a wire feed device (11) etc, which are connected by an appropriate interface to said welding unit (1) or the electricity supply (2). An additional module (27) for recovering a biometric body characteristic of a person, such as for example an electronic finger print, speech recognition, iris recognition, facial feature recognition, dynamic handwriting recognition or transponder recognition is connected to the control device (4) or welding device (1) or said electrical supply (4).

Assessing and/or determining of user authorizations using a transponder, a finger print recognition routine or the like

An electric arc welding apparatus for depositing molten metal from an advancing welding wire into a weld puddle in an open root between two juxtapositioned plates where the root extends in a welding path and is formed by converging walls terminating in generally parallel walls spaced to define a gap, which apparatus comprises a contact holder with a wire outlet, a switching power supply directing welding current to the wire as the wire passes from the outlet toward the open root, with the advancing wire defining an electrode stick out between the contact holder and the weld puddle, a circuit for sensing the length of the stick out, and control means for adjusting the welding current as a function of the sensed stick out length.

Method and apparatus for electric arc welding

(2004). Development of hot wire TIG welding methods using pulsed current to heat filler wire – research on pulse heated hot wire TIG welding processes. Welding International: Vol. 18, No. 6, pp. 456-468.

Development of hot wire TIG welding methods using pulsed current to heat filler wire – research on pulse heated hot wire TIG welding processes

A semi-automatic hot wier TIG (Tungsten Inert Gas) welding equipment comprising: a portable TIG arc torch; a portable filler wire feed torch; a hot wire switching power source for energizing the TIG arc torch, the filler wire feed torch and a base metal; a filler wire feeding device for feeding the wire to the wire feeding torch at a desired rate; a welding condition control device for controlling wire heating power so as to provide wire heating power commensurate to the wire feed rate; means for measuring the resistance value of the wire extension section between the terminal end of the wire and the terminal end of the filler wire feed torch; and means for controlling said filler wire feeding means to change the wire feed rate in response to the detected wire extension According to the present invention, the welding operations are performed while the filler wire feed torch is held in one hand and the TIG arc torch is held in the other hand, so that the position where the arc and wire are inserted can be desireably adjusted Adjustment of the welding conditions such as regulation of the welding arc current and adjustment of wire feed rate can be readily performed during welding

Semi-automatic hot wire tig welding equipment

An ultra-flat non-consumable electrode welding torch which allows performing a welding operation through a narrow gap between adjacent piping such as welding of a piping of a boiler panel, to be mounted on a compact automatic welding head, and a welding head provided with such a welding torch are provided.

Non-consumable electrode welding torch and welding head with the torch

A welding head which can easily move the torch portion of the welding head in the circumferential direction and the vertical moving direction of the outer circumference of the to-be-welded tubes even in a narrow gap, comprises a torch rotating ring 1 that rotates on the outer circumferences of the tubes 22 by matching with the central axis of the to-be-welded tubes 22 and a torch vertical moving ring 2 disposed concentrically with the ring 1 inside the ring 1, provided with a torch base 10 for supporting a torch 7 on the front ends, a first gear group for driving and rotating the ring 1 around the tubes 22, a second gear group that is disposed in parallel to the first gear group and drives and rotates the ring 2 around the tubes 22, a drive shaft 27 for driving the two gear groups, and a torch rotating motor 4 for driving the drive shaft 27, and a third gear group that can drive the ring 2 while rotating it in the same direction as or in reverse to that of the ring 1 at a speed equal to or higher or lower than that of the first gear group for rotating the ring 2 around the tubes 22 and vertically moving the torch 7, and a torch vertical moving motor for driving this third gear group

Toshiharu Myoga

Papers

Development of hot wire TIG welding methods using pulsed current to heat filler wire – research on pulse heated hot wire TIG welding processes

Semi-automatic hot wire tig welding equipment

Non-consumable electrode welding torch and welding head with the torch

All position automatic welding head and method for operating the same