Recycled Al-Si alloys prepared by gas atomization followed by additive manufacturing with improved wear behavior by in situ and layer-by-layer deposition of reinforcing particles

Department

Department of Applied Science and Technology (DISAT), Politecnico of Turin

Main research activities/topics/projects

Al-Si alloys with hypereutectic compositions (>13%Si) are potential candidates to replace cast iron parts in the transport sector. Considering that they are significantly lightweight, the mass savings can be substantial. The mechanical properties are highly dependent on the morphology, size, and distribution of the primary Si. Therefore, using recycled gas atomized Al-Si is not only beneficial for the environment but also decreases the primary Si particle size, leading to higher mechanical properties, in special wear resistance.

Recently, metal additive manufacturing techniques such as Laser Powder Bed Fusion (L-PBF) have gained attention due to the possibility of unique part design and refined microstructures. Moreover, in situ alloying is also possible since the high-power laser effectively melts the metallic powders. Considering the significance of enhancing the wear resistance of Al-Si alloys, different reinforcements can be employed such as Al2O3, Y2O3, B4C, TiB2, TiC, etc. These reinforcements are known to improve wear resistance and could be homogeneously dispersed with the proper process parameters by L-PBF.

Another possibility to attach reinforcements to metallic powders is layer-by-layer deposition that introduces fine particles to their surface. The greatest advantage is the very small particle size and their homogeneous distribution. 

In this research work, complementary activities involving a Brazilian master’s student and Politecnico di Torino laboratories will be carried out. This study aims to investigate two different techniques for the addition of reinforcing particles to recycled and atomized Al-Si alloys. The powders will be in situ alloyed by L-PBF and modified with layer-by-layer deposition with further processing by L-PBF. 

Working language

The working language can indifferently be either Italian or English.

Special entry requirements

Knowledge of gas atomizing process

 Skills in the analysis of metals powders and their properties

 Knowledge in the field of Materials Science and in Surface Engineering

 Leadership and proven ability to conduct his/her own research activities

 Excellent communication and organizational skills

Duration in months (min-max)

Master researcher:6-12