Nesma Aboulkhair

The creation of an object by selective laser melting (SLM) occurs by melting contiguous areas of a powder bed according to a corresponding digital model. It is therefore clear that the success of this metal Additive Manufacturing (AM) technology relies on the comprehension of the events that take place during the melting and solidification of the powder bed. This study was designed to understand the generation of the laser spatter that is commonly observed during SLM and the potential effects that the spatter has on the processing of 316L stainless steel, Al-Si10-Mg, and Ti-6Al-4V. With the exception of Ti-6Al-4V, the characterization of the laser spatter revealed the presence of surface oxides enriched in the most volatile alloying elements of the materials. The study will discuss the implication of this finding on the material quality of the built parts.

Selective laser melting is used to manufacture complex structures using an additive manufacturing approach with metal powders. It is generally supposed that the quality of the powder plays an important role in the success of the manufacturing process. This is because the powder morphology alongside its size distribution governs the formation of gas pores and controls theflowability. This is important as the process requires successive deposition of uniform layers of powder, which is hindered if the powder does not flow well. In this work, two batches of AlSi10Mg powder with different specifications were characterized in terms of morphology, composition, size distribution, flowability, and apparent density. Bulk samples were created from the powdersusing selective laser melting and the relative densities were compared. One of the metal powders,whichis specially produced for additive manufacturing was found to provide higher quality parts than those fabricated using the other powder,w...

ABSTRACT Precipitation hardening of selective laser melted AlSi10Mg was investigated in terms of solution heat treatment and aging duration. The influence on the microstructure and hardness was established, as was the effect on the size and density of Si particles. Although the hardness changes according to the treatment duration, the maximum hardening effect falls short of the hardness of the as-built parts with their characteristic fine microstructure. This is due to the difference in strengthening mechanisms.

Abstract Owing to its many exceptional properties, aluminium finds many applications in theaerospace, automotive, building and packaging industries. Enhancing its properties through alloyingor thermal treatments has been the focus of researchers' interests for a long time. In this work, purealuminium powders were mechanically milled for up to 12 hrs and then were cold compacted andextruded to produce bulk nanostructured material. Both tensile and compressive tests wereconducted and the results compared. Post extrusion ...

ABSTRACT The creation of an object by selective laser melting (SLM) occurs by melting contiguous areas of a powder bed according to a corresponding digital model. It is therefore clear that the success of this metal Additive Manufacturing (AM) technology relies on the comprehension of the events that take place during the melting and solidification of the powder bed. This study was designed to understand the generation of the laser spatter that is commonly observed during SLM and the potential effects that the spatter has on the processing of 316L stainless steel, Al-Si10-Mg, and Ti-6Al-4V. With the exception of Ti-6Al-4V, the characterization of the laser spatter revealed the presence of surface oxides enriched in the most volatile alloying elements of the materials. The study will discuss the implication of this finding on the material quality of the built parts.