Impact of Interlayer Dwell Time on Microstructure and Mechanical Properties of Nickel and Titanium Alloys

Foster, Bryant; Beese, Allison M.; Keist, Jayme S.; McHale, E.T.; Palmer, Todd

doi:10.1007/s11661-017-4164-0

Cited by 43 publications

(17 citation statements)

References 31 publications

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“…Other contributions have focused on different impacts of dwell time. In [22], Foster et al studied both Inconel 625 and Ti-6Al-4V in terms of microstructure, hardness and mechanical behavior, their results are the following. Vickers' microhardness and the yield and tensile strengths increase with the addition of an inter-layer dwell time for both alloys.…”

Section: Introductionmentioning

confidence: 99%

Influence of interlayer dwell time on the microstructure of Inconel 718 Laser Cladded components

Guévenoux

Hallais

Charles

et al. 2020

Optics & Laser Technology

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Laser Cladding is one of the leading additive manufacturing technologies enabling the repair of metallic components. Their fatigue reliability depends directly on the material microstructure and consequently on the process parameters. This study highlights the influence of the interlayer dwell time on single-track walls for Inconel 718 repaired components. EBSD analyses show that dwell time both reduces grain size and creates a textural stretch of the microstructure. An optimal dwell time between the writing of successive layers can then be introduced to target a specified microstructure gradient at the interface between the original part and the repaired deposit.

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Section: Introductionmentioning

confidence: 99%

Influence of interlayer dwell time on the microstructure of Inconel 718 Laser Cladded components

Guévenoux

Hallais

Charles

et al. 2020

Optics & Laser Technology

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“…The inclusion of dwell time between the writing of two successive layers introduces an additional cooling period in the process and therefore changes the thermal field both in terms of history and in terms of temporal or spatial gradients [5,16]. This will affect the final geometrical distorsion of the part and the underlying residual stresses [15,16] as well as the microstructure and consequently the mechanical and fatigue behavior, characterized for example by microhardness [17,18].…”

Section: Introductionmentioning

confidence: 99%

Plastic strain localization induced by microstructural gradient in laser cladding repaired structures

Guévenoux

Hallais

Balit

et al. 2020

Theoretical and Applied Fracture Mechanics

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Laser Cladding is an additive manufacturing technology well suited for the repair of complex metallic components. The repair is a two-step process: first, one removes the worn region and then, the initial geometry is reconstructed locally. The aim of this work is to study the influence of the microstructural gradient on the strain localization in repaired structures. More precisely, we perform in-situ SEM tensile tests completed by EBSD observations of the microstructure in the interface neighborhood between the base material and the repaired region. Furthermore, we monitor the evolution of the local plastic strain distribution at the grain level until failure. This is performed by Digital Image Correlation methods and superposition of grains contours and strain maps. The observations of grain size and plasticity are compared with predictions provided by a Hall-Petch model. The study emphasizes the importance of the microstructural gradient in the vicinity of reparation interface, more precisely it reveals that this gradient induce multiaxial strains and that the strain localization phenomenon is governed mainly by a grain size effect.

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“…Suryakumar et al (2013) claimed that depending on the thermal cycles in WAAM-fabricated steel, coarse grained microstructures with inhomogeneous hardness are formed along the building direction. Foster et al (2017) reported that increasing dwell time result in a slight decrease in the alpha lath widths and a more noticeable decrease in the width of prior beta grains during manufactured Ti6Al4V using directed energy deposition process. These findings suggest that there is a tremendous need for microstructural optimization through improvements in process control of additive manufacturing.…”

Section: Introductionmentioning

confidence: 99%

The effects of forced interpass cooling on the material properties of wire arc additively manufactured Ti6Al4V alloy

Ding

Cuiuri

et al. 2018

Journal of Materials Processing Technology

181

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To achieve improved microstructure and mechanical properties, an innovative wire arc additive manufacturing (WAAM) process with forced interpass cooling using compressed CO 2 was employed in this study to fabricate Ti6Al4V thin-walled structures. The effects of various interpass temperatures and rapid forced cooling on deposition geometry, surface oxidation, microstructural evolution, and mechanical properties of the fabricated part were investigated by laser profilometry, optical microscopy (OM), scanning electron microscopy (SEM), hardness testing and mechanical tensile testing. Results show that the microstructural evolution and mechanical properties of the deposited metal are not greatly affected by an increasing interpass temperature, however, the deposited wall tends to be widened, flattened and exhibit increased surface oxidation through visible coloration. When rapid forced cooling using CO 2 is used between deposited layers, slightly higher hardness values and increased strength can be obtained. This is mainly attributed to the combined effects of less surface oxide and high density dislocation caused by the generation of large amounts of fine-grained acicular α within the microstructure. Furthermore, forced interpass cooling not only improves deposition properties, but also promotes geometrical repeatability and also improved manufacturing efficiency through the reduction of dwell time between deposited layers. ABSTRACTTo achieve improved microstructure and mechanical properties, an innovative wire arc additive manufacturing (WAAM) process with forced interpass cooling using compressed CO 2 was employed in this study to fabricate Ti6Al4V thin-walled structures. The effects of various interpass temperatures and rapid forced cooling on deposition geometry, surface oxidation, microstructural evolution, and mechanical properties of the fabricated part were investigated by laser profilometry, optical microscopy (OM), scanning electron microscopy (SEM), hardness testing and mechanical tensile testing. Results show that the microstructural evolution and mechanical properties of the deposited metal are not greatly affected by an increasing interpass temperature, however, the deposited wall tends to be widened, flattened and exhibit increased surface oxidation through visible coloration. When rapid forced cooling using CO 2 is used between deposited layers, slightly higher hardness values and increased strength can be obtained. This is mainly attributed to the combined effects of less surface oxide and high density dislocation caused by the generation of large amounts of fine-grained acicular α within the microstructure. Furthermore, 2 forced interpass cooling not only improves deposition properties, but also promotes geometrical repeatability and also improved manufacturing efficiency through the reduction of dwell time between deposited layers.

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Impact of Interlayer Dwell Time on Microstructure and Mechanical Properties of Nickel and Titanium Alloys

Cited by 43 publications

References 31 publications

Influence of interlayer dwell time on the microstructure of Inconel 718 Laser Cladded components

Influence of interlayer dwell time on the microstructure of Inconel 718 Laser Cladded components

Plastic strain localization induced by microstructural gradient in laser cladding repaired structures

The effects of forced interpass cooling on the material properties of wire arc additively manufactured Ti6Al4V alloy

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