Filippo Belelli

Mr. Filippo Belelli

Politecnico di Milano - Department of Mechanical Engineering

Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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26 December 2020 in Metals
Verified
Journal Article
Open access
PDF file
FBFilippo Belelli
Filippo Belelli
Riccardo CasatiRiccardo Casati
Riccardo Casati
MRMartina Riccio
Martina Riccio
ARAlessandro Rizzi
Alessandro Rizzi
MKmevlüt yunus Kayacan
mevlüt yunus Kayacan
Maurizio VedaniMaurizio Vedani
Maurizio Vedani
The number of available materials for Laser Powder Bed Fusion is still limited due to the poor processability of many standard alloys. In particular, the lack of high-strength aluminium alloys, widely used in aerospace and automotive industries, remains a big issue for the spread of beam-based additive manufacturing technologies. In this study, a novel high-strength aluminium alloy for high temperature applications having good processability was developed. The design of the alloy was done based on the chemical composition of the widely used EN AW 2618. This Al-Cu-Mg-Ni-Fe alloy was modified with Ti and B in order to promote the formation of TiB2 nuclei in the liquid phase able to stimulate heterogeneous nucleation of grains and to decrease the hot cracking susceptibility of the material. The new Al alloy was manufactured by gas atomisation and processed by Laser Powder Bed Fusion. Samples produced with optimised parameters featured relative density of 99.91%, with no solidification cracks within their microstructure. After aging, the material revealed upper yield strength and ultimate tensile strength of 495 MPa and 460 MPa, respectively. In addition, the alloy showed tensile strength higher than wrought EN AW 2618 at elevated temperatures.

1 April 2021 in Applied Sciences
Verified
Journal Article
Open access
PDF file
JVJörg Volpp
Jörg Volpp
FBFilippo Belelli
Filippo Belelli
Riccardo CasatiRiccardo Casati
Riccardo Casati
Laser Powder-Bed Fusion (LPBF) is one method in Additive Manufacturing where layer-wise complex structures can be built. However, although the LPBF machines produce promising parts, the efficiency and process speed are typically still low, which can make the process expensive and uneconomical. Recent research showed that volume elements in the parts can be melted several times, while only a small material volume is added, which indicates a high loss of energy. In order to understand the process better, in this work, theoretical modeling and smart powder-bed experiments were designed to explain the impact on the track dimensions based on the previously built tracks and layers. It was found that the powder availability varies for each track and has an alternating character within and between layers. The comparison of the simulation and experimental results indicates that the powder pick-up from neighboring powder volumes is the main reason for the variations of the powder availability.