Investigation of the sensitivity of the fatigue resistance to defect position in aluminium alloys obtained by Selective laser melting using artificial defects

This study investigates the very-high-cycle fatigue (VHCF) behavior at elevated temperature (650 °C) of the Inconel 718 alloy fabricated by selective laser melting (SLM). The results are compared with those of the wrought alloy. Large columnar grain with a cellular structure in the grain interior and Laves/δ phases precipitated along the grain boundaries were exhibited in the SLM alloy, while fine equiaxed grains were present in the wrought alloy. The elevated temperature had a minor effect on the fatigue resistance in the regime below 108 cycles for the SLM alloy but significantly reduced the fatigue strength in the VHCF regime above 108 cycles. Both the SLM and wrought specimens exhibited similar fatigue resistance in the fatigue life regime of fewer than 107–108 cycles at elevated temperature, and the surface initiation mechanism was dominant in both alloys. In a VHCF regime above 107–108 cycles at elevated temperature, the wrought material exhibited slightly better fatigue resistance than the SLM alloy. All fatigue cracks are initiated from the internal defects or the microstructure discontinuities. The precipitation of Laves and δ phases is examined after fatigue tests at high temperatures, and the effect of microstructure on the formation and the propagation of the microstructural small cracks is also discussed.

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Aspects of the Process and Material Relationships in the Selective Laser Melting of Aluminium Alloys

TMS 2015 144th Annual Meeting & Exhibition ◽

10.1007/978-3-319-48127-2_50 ◽

2015 ◽

pp. 397-404

Author(s):

M. Simonelli ◽

N. Aboulkhair ◽

I. Maskery ◽

C. Tuck ◽

I. Ashcroft ◽

...

Keyword(s):

Selective Laser Melting ◽

Aluminium Alloys ◽

Laser Melting

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Properties of Aluminium Alloys Produced by Selective Laser Melting

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.710.83 ◽

2016 ◽

Vol 710 ◽

pp. 83-88 ◽

Cited By ~ 3

Author(s):

Paola Bassani ◽

Carlo Alberto Biffi ◽

Riccardo Casati ◽

Adrianni Zanatta Alarcon ◽

Ausonio Tuissi ◽

...

Keyword(s):

Mechanical Properties ◽

Additive Manufacturing ◽

Selective Laser Melting ◽

Aluminium Alloys ◽

Al Alloys ◽

Laser Melting ◽

Microstructural Refinement ◽

Manufacturing Techniques

Analysis of peculiar properties offered by Al alloys produced according to additive manufacturing techniques, specifically by Selective Laser Melting (SLM), is carried out. Two alloys are considered, derived by casting (AlSi10Mg) and by wrought (ENAW 2618) applications. The SLM processed samples are investigated considering their microstructural and mechanical properties after SLM and compared to cast and wrought counterparts. A strong microstructural refinement induced by SLM processing is observed for both alloys, resulting in excellent hardness properties. Investigation on integrity of samples revealed that small-size microvoids and unmelted regions could be present in SLM parts.

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Influence of defect size on the fatigue resistance of AlSi10Mg alloy elaborated by selective laser melting (SLM)

Procedia Structural Integrity ◽

10.1016/j.prostr.2017.11.063 ◽

2017 ◽

Vol 7 ◽

pp. 75-83 ◽

Cited By ~ 21

Author(s):

Julius N. Domfang Ngnekou ◽

Yves Nadot ◽

Gilbert Henaff ◽

Julien Nicolai ◽

Lionel Ridosz

Keyword(s):

Selective Laser Melting ◽

Fatigue Resistance ◽

Defect Size ◽

Laser Melting

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On the mechanical behaviour of titanium alloy TiAl6V4 manufactured by selective laser melting: Fatigue resistance and crack growth performance

International Journal of Fatigue ◽

10.1016/j.ijfatigue.2012.11.011 ◽

2013 ◽

Vol 48 ◽

pp. 300-307 ◽

Cited By ~ 622

Author(s):

S. Leuders ◽

M. Thöne ◽

A. Riemer ◽

T. Niendorf ◽

T. Tröster ◽

...

Keyword(s):

Titanium Alloy ◽

Growth Performance ◽

Crack Growth ◽

Selective Laser Melting ◽

Fatigue Resistance ◽

Mechanical Behaviour ◽

Laser Melting

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3D printing of Aluminium alloys: Additive Manufacturing of Aluminium alloys using selective laser melting

Progress in Materials Science ◽

10.1016/j.pmatsci.2019.100578 ◽

2019 ◽

Vol 106 ◽

pp. 100578 ◽

Cited By ~ 119

Author(s):

Nesma T. Aboulkhair ◽

Marco Simonelli ◽

Luke Parry ◽

Ian Ashcroft ◽

Christopher Tuck ◽

...

Keyword(s):

Additive Manufacturing ◽

3D Printing ◽

Selective Laser Melting ◽

Aluminium Alloys ◽

Laser Melting

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On the effect of shot-peening on fatigue resistance of AlSi10Mg specimens fabricated by additive manufacturing using selective laser melting (AM-SLM)

Additive Manufacturing ◽

10.1016/j.addma.2018.03.030 ◽

2018 ◽

Vol 21 ◽

pp. 458-464 ◽

Cited By ~ 34

Author(s):

Naor Elad Uzan ◽

Shlomo Ramati ◽

Roni Shneck ◽

Nachum Frage ◽

Ori Yeheskel

Keyword(s):

Additive Manufacturing ◽

Selective Laser Melting ◽

Fatigue Resistance ◽

Shot Peening ◽

Laser Melting

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Investigation on pulsed electrolytically polished AlSi10Mg alloy processed via selective laser melting technique

Proceedings of the Institution of Mechanical Engineers Part L Journal of Materials Design and Applications ◽

10.1177/14644207211045301 ◽

2021 ◽

pp. 146442072110453

Author(s):

S. Anand Kumar ◽

Anigani Sudarshan Reddy ◽

Snehith Mathias ◽

Abhishek Shrivastava ◽

Prasad Raghupatruni

Keyword(s):

Surface Roughness ◽

Surface Topography ◽

Selective Laser Melting ◽

Surface Integrity ◽

Current Density ◽

Aluminium Alloys ◽

Surface Finishing ◽

Laser Melting ◽

X Ray ◽

Ratio Curve

Currently, the surface integrity-related issues of additively manufactured parts are limiting the potential high-end applications. The present work investigates the effectiveness of the pulsed-electropolishing technique to improve the surface integrity of aluminium alloys fabricated using the selective laser melting (SLM) technique. Due to its low density, high corrosion resistance, the aluminium alloys considerably enhance the performance of lightweight critical parts for different industrial applications. In this study, selective laser melted AlSi10Mg samples were subjected to microstructural examinations using optical microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray diffraction technique. The microhardness and tensile properties were determined using a microhardness tester and a universal testing machine, respectively. The pulsed-electropolishing process was employed for the surface finishing of the SLM-processed AlSi10Mg samples. The effect of current density on the electropolishing of selective laser melted AlSi10Mg alloy were also investigated. The microstructures of printed samples revealed a density of greater than 99.9% and weld beads along the build direction (longitudinal) and laser scan paths perpendicular to the build direction (transverse). The microhardness, yield and tensile strength properties were similar in both as-printed conditions. The pulsed electropolishing results showed a beneficial effect of higher current density values, resulting in decreased surface roughness of the SLM-processed AlSi10Mg samples. Compared to as-printed conditions, a significant decrease in surface roughness of about ∼73.35% under optimized electropolishing conditions was noted. The material ratio curve shows that the surface topography becomes more uniform with increased current density and has lesser surface undulations for as-printed samples. The 2D line profilogram and 3D surface topography of electropolished SLM-processed samples reveal the surface finish quality characteristics. The material ratio curve aids as an effective method to assess and qualify the surface topography of electropolished samples.

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