Publications de Milad Hamidi Nasab

Fast and accurate laser powder bed fusion metamodels predicting melt pool dimensions, effective laser absorptivity and lack of fusion defects

Roland Logé, Jamasp Jhabvala, Eric Boillat, Milad Hamidi Nasab

The significant computational expenses associated with simulating the Laser Powder Bed Fusion (LPBF) process often restrict the insights gained from modeling endeavors to specific combinations of process parameters, hindering broader conclusions. In this s ...

2025

Acoustic emission signature of martensitic transformation in laser powder bed fusion of Ti6Al4V-Fe, supported by operando X-ray diffraction

Roland Logé, Jamasp Jhabvala, Mathijs Pieter van der Meer, Milad Hamidi Nasab

This study focuses on investigating Acoustic Emission (AE) monitoring in the Laser Powder Bed Fusion (LPBF) process, using premixed Ti6Al4V-(x wt%) Fe, where x = 0, 3, and 6. By employing a structure-borne AE sensor, we analyze AE data statistically, uncov ...

2024

Monitoring of laser-induced fast recrystallization in SS-316L through synchrotron X-ray diffraction

Roland Logé, Cyril Cayron, Milad Hamidi Nasab

Laser based heat treatments have multiple applications for local tuning of microstructures. They are particularly relevant in the context of laser-based additive manufacturing (LAM), in order to relieve residual stresses or introduce equiaxed structures th ...

Elsevier Sci Ltd2024

Experimental quantification of inward Marangoni convection and its impact on keyhole threshold in laser powder bed fusion of stainless steel

Roland Logé, Christian Leinenbach, Milad Hamidi Nasab

Laser metal additive manufacturing has the potential to revolutionize the production of complex geometries with high precision across various industrial applications. To optimize the reliability of the process, a detailed understanding of the melt pool dyn ...

Elsevier2024

Healing of keyhole porosity by means of defocused laser beam remelting: Operando observation by X-ray imaging and acoustic emission-based detection

Roland Logé, Milad Hamidi Nasab

One of the remaining challenges in Laser Powder Bed Fusion (LPBF) of metals is the control of the formation of keyhole pores, resulting from a local excessive energy input during processing. Such defects can lead to degraded mechanical properties and are t ...

Elsevier2023

Harmonizing sound and light: X-ray imaging unveils acoustic signatures of stochastic inter-regime instabilities during laser melting

Roland Logé, Florian Aymanns, Milad Hamidi Nasab

Laser powder bed fusion (LPBF) is a metal additive manufacturing technique involving complex interplays between vapor, liquid, and solid phases. Despite LPBF's advantageous capabilities compared to conventional manufacturing methods, the underlying physica ...

Nature Portfolio2023

In-situ selective laser heat treatment for microstructural control of additively manufactured Ti-6Al-4V

Roland Logé, Cyril Cayron, Milad Hamidi Nasab

As-built Laser Powder Bed Fusion (LPBF) Ti-6Al-4V typically exhibits a fully acicular alpha '-martensite microstructure, and requires post-process heat treatment in order to decompose the martensite and achieve sufficient ductility. In the present study, w ...

Elsevier2023

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

Deep learning-based monitoring of laser powder bed fusion process on variable time-scales using heterogeneous sensing and operando X-ray radiography guidance

Roland Logé, Milad Hamidi Nasab

Harnessing the full potential of the metal-based Laser Powder Bed Fusion process (LPBF) relies heavily on how effectively the overall reliability and stability of the manufactured part can be ensured. To this aim, the recent advances in sensorization and p ...

ELSEVIER2022

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

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

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