Microstructure and residual stress improvement in wire and arc additively manufactured parts through high-pressure rolling

Colegrove, Paul A.; Coules, Harry; Fairman, Julian; Martina, Filomeno; Kashoob, Tariq; Mamash, Hani; Cozzolino, Luis Daniel

doi:10.1016/j.jmatprotec.2013.04.012

Cited by 382 publications

(275 citation statements)

References 19 publications

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“…The model assumes very simple stress state with only the longitudinal component being nonzero and it is fully characterised by a single parameter, the deposition stress σ d or, equivalently, the curvature κ. The fact that the normal and transverse stresses can be accepted as zero for all practical purposes has a solid experimental corroboration in this study as well as in other studies [4,6]. While not every detail can be derived with the simple analytical model, it is clear that the main trend and magnitude of stress distribution in the wall can be reproduced.…”

Section: Discussionsupporting

confidence: 84%

“…For experimental studies, a single wall structure (T-shape sample) of a constant thickness and height, built on a rectangular base plate appears to be a standard choice [3][4][5][6]. Depending on the material, exact dimensions of the build-up and the process, the deflection of the back side of the base plate can vary greatly, but a typical reported deflection of the base plate in case of Ti-6Al-4V is 14 mm per 1000 mm longitudinal base length [6].…”

Section: Introductionmentioning

confidence: 99%

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Stress in Thin Wall Structures Made by Layer Additive Manufacturing

Luzin

Hoye

2016

Residual Stresses 2016

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Abstract. Manufacturing of thin wall structures is one of the main applications of additive manufacturing, where it has significant advantages over traditional milling and machining techniques or welded analogues. Such thin walled structures are common in structural aerospace components, and are also frequently made from titanium alloys. For such large-scale components, layer deposition strategy is more advantageous rather than a pixel-wise deposition approach due to the demand for high productivity and size requirements. Several techniques can be used to produce layer-wise buildups, including laser-powered Direct Metal Deposition (DMD) process or gas tungsten arc welding (GTAW). Although, in the general case of arbitrary thin wall structures the stress distribution is complex, for some simple geometries, the stress state is simple and can be well characterized within a model by a single parameter representing a layer deposition stress in the steady-state regime. The model calculations were verified by experimental results on a thin-walled sample component that was manufactured from Ti-6Al-4V by GTAW with the residual stresses measured using KOWARI neutron strain scanner at the OPAL research reactor (ANSTO).

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Section: Discussionsupporting

confidence: 84%

Section: Introductionmentioning

confidence: 99%

Stress in Thin Wall Structures Made by Layer Additive Manufacturing

Luzin

Hoye

2016

Residual Stresses 2016

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“…Compared with the poor energy efficiency of laser and electron beam, the energy efficiency of arc welding processes such as the Gas Metal Arc Welding (GMAW) or Gas Tungsten Arc Welding (GTAW) processes can be as high as 90% in some circumstances [17,18]. As a result, WAAM using either the GMAW or the GTAW process is a promising technology for manufacturing aerospace components with median to large size in terms of productivity, costcompetitiveness and energy efficiency [5,6,19,20].…”

Section: Introductionmentioning

confidence: 99%

A multi-bead overlapping model for robotic wire and arc additive manufacturing (WAAM)

Ding

Pan

Cuiuri

et al. 2015

Robotics and Computer-Integrated Manufacturing

396

132

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Wire and arc additive manufacturing (WAAM) is a promising alternative to traditional subtractive manufacturing for fabricating large aerospace components that feature high buy-to-fly ratio. Since the WAAM process builds up a part with complex geometry through the deposition of weld beads on a layer-by-layer basis, it is important to model the geometry of a single weld bead as well as the multi-bead overlapping process in order to achieve high surface quality and dimensional accuracy of the fabricated parts. This study firstly builds models for a single weld bead through various curve fitting methods. The experimental results show that both parabola and cosine functions accurately represent the bead profile. The overlapping principle is then detailed to model the geometry of multiple beads overlapping together. The tangent overlapping model (TOM) is established and the concept of the critical centre distance for stable multi-bead overlapping processes is presented. The proposed TOM is shown to provide a much better approximation to the experimental measurements when compared with the traditional flat-top overlapping model (FOM). This is critical in process planning to achieve better geometry accuracy and material efficiency in additive manufacturing. Abstract: Wire and arc additive manufacturing (WAAM) is a promising alternative to traditional subtractive manufacturing for fabricating large aerospace components that feature high buy-to-fly ratio. Since the WAAM process builds up a part with complex geometry through the deposition of weld beads on a layer-by-layer basis, it is important to model the geometry of a single weld bead as well as the multi-bead overlapping process in order to achieve high surface quality and dimensional accuracy of the fabricated parts. This study firstly builds models for a single weld bead through various curve fitting methods. The experimental results show that both parabola and cosine functions accurately represent the bead profile. The overlapping principle is then detailed to model the geometry of multiple beads overlapping together. The Tangent Overlapping Model (TOM) is established and the concept of the critical centre distance for stable multi-bead overlapping processes is presented. The proposed TOM is shown to provide a much better approximation to the experimental measurements when compared with the traditional Flat-top Overlapping Model (FOM). This is critical in process planning to achieve better geometry accuracy and material efficiency in additive manufacturing.

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“…There is potential for the aerospace industry to greatly benefit from Additive Manufacture (AM) as it allows the near-net-shape manufacture of components [1][2][3][4][5][6][7] and provides more design freedom than traditional manufacturing, which can facilitate substantial weight savings through better design optimisation [1]. Ti-6Al-4V is one of the most widely used titanium aerospace alloys due to its high specific properties [8].…”

Section: Introductionmentioning

confidence: 99%

“…In AM processes a component is built up from multiple tracks with a small moving heat source which can lead to the development of substantial residual stresses and distortion [5]. Similar stresses are accrued with a single track deposition in traditional welds, and have previously been relieved by imparting a compensating plastic strain by treatments such as peening [14] and rolling [15].…”

Section: Introductionmentioning

confidence: 99%