Effect of Surface and Subsurface Defects on Fatigue Behavior of AlSi10Mg Alloy Processed by Laser Powder Bed Fusion (L-PBF)

The fatigue behaviour of an AlSi10Mg alloy processed by laser powder bed fusion (L-PBF) and subjected to different surface finishing processes was investigated paying special attention to the residual defects on the surface and the dominant fatigue failure mechanisms. Roughness measurements and qualitative surface morphology analysis showed smooth surfaces in the case of vibro-finishing and machining followed by polishing. The fatigue performance did not reveal to be directly related to surface roughness, but residual intrusions left on the finished surfaces. Post-mortem analysis showed single- or multiple-crack nucleation from pores opened on the surface, un-melted powders, or spatters considered as typical L-PBF defects. A fatigue limit of 195 MPa for machined and polished samples was obtained by substantial removal of surface and subsurface defects.

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Gold, Silver, and Electrum Electroless Plating on Additively Manufactured Laser Powder-Bed Fusion AlSi10Mg Parts: A Review

Coatings ◽

10.3390/coatings11040422 ◽

2021 ◽

Vol 11 (4) ◽

pp. 422

Author(s):

Dana Ashkenazi ◽

Alexandra Inberg ◽

Yosi Shacham-Diamand ◽

Adin Stern

Keyword(s):

Additive Manufacturing ◽

Low Cost ◽

Ion Beam ◽

Surface Finishing ◽

Powder Bed Fusion ◽

Laser Powder Bed Fusion ◽

Powder Bed ◽

Finishing Process ◽

Gold Silver ◽

3D Printed

Additive manufacturing (AM) revolutionary technologies open new opportunities and challenges. They allow low-cost manufacturing of parts with complex geometries and short time-to-market of products that can be exclusively customized. Additive manufactured parts often need post-printing surface modification. This study aims to review novel environmental-friendly surface finishing process of 3D-printed AlSi10Mg parts by electroless deposition of gold, silver, and gold–silver alloy (e.g., electrum) and to propose a full process methodology suitable for effective metallization. This deposition technique is simple and low cost method, allowing the metallization of both conductive and insulating materials. The AlSi10Mg parts were produced by the additive manufacturing laser powder bed fusion (AM-LPBF) process. Gold, silver, and their alloys were chosen as coatings due to their esthetic appearance, good corrosion resistance, and excellent electrical and thermal conductivity. The metals were deposited on 3D-printed disk-shaped specimens at 80 and 90 °C using a dedicated surface activation method where special functionalization of the printed AlSi10Mg was performed to assure a uniform catalytic surface yielding a good adhesion of the deposited metal to the substrate. Various methods were used to examine the coating quality, including light microscopy, optical profilometry, XRD, X-ray fluorescence, SEM–energy-dispersive spectroscopy (EDS), focused ion beam (FIB)-SEM, and XPS analyses. The results indicate that the developed coatings yield satisfactory quality, and the suggested surface finishing process can be used for many AM products and applications.

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On the constitutive relationship between solidification cells and the fatigue behaviour of IN718 fabricated by laser powder bed fusion

Additive Manufacturing ◽

10.1016/j.addma.2021.102347 ◽

2021 ◽

pp. 102347

Author(s):

Alessandro Piglione ◽

Bonnie Attard ◽

Vitor Vieira Rielli ◽

Claudia-Tatiana Santos Maldonado ◽

Moataz M. Attallah ◽

...

Keyword(s):

Fatigue Behaviour ◽

Constitutive Relationship ◽

Powder Bed Fusion ◽

Laser Powder Bed Fusion ◽

Powder Bed

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Gold–Silver Electroless Plating on Laser Powder-Bed Fusion Additively Printed AlSi10Mg Parts

Metals ◽

10.3390/met10050557 ◽

2020 ◽

Vol 10 (5) ◽

pp. 557 ◽

Cited By ~ 1

Author(s):

Alexandra Inberg ◽

Dana Ashkenazi ◽

Giora Kimmel ◽

Yosi Shacham-Diamand ◽

Adin Stern

Keyword(s):

Deposition Process ◽

Xrd Analysis ◽

Binding Energies ◽

Surface Finishing ◽

Powder Bed Fusion ◽

Laser Powder Bed Fusion ◽

Powder Bed ◽

Developed Surface ◽

Finishing Process ◽

Gold Silver

The current research presents a novel methodology for surface finishing of printed AlSi10Mg parts by electroless deposited gold–silver (electrum) alloys. The parts were printed by additive manufacturing laser powder-bed fusion (AM-LPBF). The electrum was chosen due to its appearance and good electrical and thermal properties and was deposited on disk-shaped specimens at 80 and 90 °C. The coating quality and appearance were studied by different methods for various deposition times and film thicknesses. The results indicate that Au–Ag coatings of AM-LPBF AlSi10Mg yield satisfactory results. The XRD analysis revealed that the coatings were composed of Au–Ag crystalline phases and beneath them, a quasi-amorphous or mixed quasi-amorphous and nanocrystalline Ni–P interlayer. The mechanism of electrum formation was studied based on the XPS analysis results as a function of the temperature and concentration. At 80 °C, the Ag was dominant at the beginning of the deposition process, while at 90 °C the Au was first detected on the interface. This result was explained by the electrochemical properties of alloying metals and the binding energies required to form metal–Ni and Au–Ag bonding. The results indicate that the electrum coatings are satisfactory, and the developed surface finishing process could be used for many applications.

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