Publications de Navid Sohrabi | EPFL Graph Search

Quantitative prediction of crystallization in laser powder bed fusion of a Zr-based bulk metallic glass with high oxygen content

Jamasp Jhabvala, Roland Logé, Hossein Ghasemi Tabasi, Navid Sohrabi, Toni Ivas

One of the main challenges in the fabrication of bulk metallic glasses (BMGs) via laser-based additive manufacturing (AM) is undesirable crystal phase formation, which usually deteriorates the mechanical properties of the BMG fabricated parts. Understandin ...

Elsevier Sci Ltd2024

Laser powder-bed fusion of a high entropy alloy with outstanding intrinsic mechanical properties

Cyril Cayron, Jamasp Jhabvala, Václav Pejchal, Roland Logé, Navid Sohrabi

In the past few years, laser powder-bed fusion (LPBF) of high entropy alloys (HEAs) has gained significant interest. We investigated a HEA (PdPtRhIrCuNi) elaborated by LPBF, and studied its microstructure and mechanical properties. This alloy has potential ...

ELSEVIER SCIENCE SA2023

An investigation on the fatigue behavior of additively manufactured laser shock peened AlSi7Mg alloy surfaces

Roland Logé, Navid Sohrabi, Milad Hamidi Nasab

In the recent years, laser powder bed fusion of aluminum alloys has attracted extensive attention due to their capacious application in the biomedical, aerospace, and other industrial sectors. This is due to the combined capabilities of the laser powder be ...

ELSEVIER SCIENCE INC2023

Direct observation of crack formation mechanisms with operando Laser Powder Bed Fusion X-ray imaging

Eric Boillat, Jamasp Jhabvala, Helena Van Swygenhoven, Roland Logé, Samy Hocine, Hossein Ghasemi Tabasi, Navid Sohrabi

Laser powder bed fusion (L-PBF) is a versatile additive manufacturing process that can print geometrically complex metal parts for a variety of applications. However, poor control of defect formation during processing hampers its widespread industrial adop ...

ELSEVIER2022

Additive Manufacturing of Bulk Metallic Glasses-Process, Challenges and Properties: A Review

Jamasp Jhabvala, Roland Logé, Navid Sohrabi

Bulk Metallic Glasses (BMG) are metallic alloys that have the ability to solidify in an amorphous state. BMGs show enhanced properties, for instance, high hardness, strength, and excellent corrosion and wear resistance. BMGs produced by conventional method ...

MDPI2021

Additive manufacturing of a precious bulk metallic glass

Jamasp Jhabvala, Güven Kurtuldu, Antonia Neels, Roland Logé, Navid Sohrabi, Annapaola Parrilli

For the first time, a high-density amorphous and crack-free bulk metallic glass (BMG) based on a precious metal (PdCuNiP) was produced via additive manufacturing (AM). Laser powder-bed fusion (LPBF) was used for the fabrication of the samples, and led to a ...

2021

Fatigue Performance of an Additively Manufactured Zr-Based Bulk Metallic Glass and the Effect of Post-Processing

Jamasp Jhabvala, Roland Logé, Navid Sohrabi, Milad Hamidi Nasab, Baptiste Thomas Jean Rouxel, Annapaola Parrilli

Fatigue is the most common cause of failure of mechanical parts in engineering applications. In the current work, we investigate the fatigue life of a bulk metallic (BMG) glass fabricated via additive manufacturing. Specimens fabricated via laser powder-be ...

MDPI2021

Critical crystallization properties of an industrial-grade Zr-based metallic glass used in additive manufacturing

Jamasp Jhabvala, Roland Logé, Navid Sohrabi

The major challenge to overcome when processing metallic glasses (MGs) is to avoid crystallization. Therefore, time-temperature-transformation (TTT) diagrams are used, but they are often derived from experiments in which heating or cooling rates are limite ...

2021

Laser powder-bed fusion of metallic alloys with enhanced microstructures and properties

Navid Sohrabi

Laser powder-bed fusion (LPBF) is an additive manufacturing (AM) process that uses a laser to selectively melt a powder bed. This process can build dense samples with complicated geometries from a wide variety of metallic alloys. In this thesis, LPBF of al ...

EPFL2021

Tensile and Impact Toughness Properties of a Zr-Based Bulk Metallic Glass Fabricated via Laser Powder-Bed Fusion

Jamasp Jhabvala, Antonia Neels, Roland Logé, Navid Sohrabi, Annapaola Parrilli

In the past few years, laser powder-bed fusion (LPBF) of bulk metallic glasses (BMGs) has gained significant interest because of the high heating and cooling rates inherent to the process, providing the means to bypass the crystallization threshold. In thi ...

MDPI2021

Laser coating of a Zr-based metallic glass on an aluminum substrate

Stefano Mischler, Jamasp Jhabvala, Alejandro Roda Buch, Roland Logé, Navid Sohrabi

Cladding of a Zr-based metallic glass (MG) on an aluminum substrate was conducted using a layer-wise laser additive manufacturing (AM) method, leading to relative densities higher than 99%. The thickness of the cladding was about 300 μm. The effect of lase ...

2020

Characterization, mechanical properties and dimensional accuracy of a Zr-based bulk metallic glass manufactured via laser powder-bed fusion

Jamasp Jhabvala, Güven Kurtuldu, Steven Van Petegem, Antonia Neels, Roland Logé, Efthymios Polatidis, Navid Sohrabi, Annapaola Parrilli

Bulk metallic glasses (BMGs) are high-strength, highly elastic materials due to their disordered atomic structure. Because BMGs require sufficiently high cooling rates to bypass crystallization, laser-based additive manufacturing (AM) methods have recently ...

2020

Healing cracks in selective laser melting by 3D laser shock peening

Jamasp Jhabvala, Andreas Burn, Christian Leinenbach, Roland Logé, Nikola Kalentics, Hossein Ghasemi Tabasi, Navid Sohrabi

Selective Laser Melting (SLM) of Ni-based superalloys such as CM247LC is prone to weld-cracking. This paper investigates how to suppress cracks by repeatedly applying Laser Shock Peening (LSP) during the building phase of SLM. Samples made of CM247LC were ...

ELSEVIER2019