Effect of silicon content on densification, mechanical and thermal properties of Al-xSi binary alloys fabricated using selective laser melting

Abstract

The effect of the silicon content on the densification of Al-xSi binary alloys (x = 0, 1, 4, 7, 10, 12, and 20 mass%) fabricated using selective laser melting (SLM) were systematically studied. By optimizing laser scanning parameters for each Al-xSi powder, almost fully dense SLM samples (more than 99.5% relative density) could be achieved for the Al-0Si (pure aluminum), and Al-4~20Si alloys. The Al-1Si SLM sample, on the other hand, contained many microcracks, considered to be solidification cracks. The Al-1Si SLM sample, in the solid-liquid coexisting state, was brittle and no healing of

In-situ alloying of AlSi10Mg+Si using Selective Laser Melting to control the coefficient of thermal expansion

“…Furthermore, processing parameters optimized for prealloyed powder have to be adjusted when processing powder mixtures as constituents with varying melting temperatures have to be molten [25]. More recently increased research interest has been devoted to the fabricability as well as mechanical and physical properties of SLMed hypereutectic AlSi alloys using prealloyed powders [26][27][28] and powder mixtures [29][30][31], respectively. Kimura et al [27] investigated the densification behavior, mechanical properties and thermal conductivity for a range of prealloyed hypoeutectic, eutectic and hypereutectic AlSi alloys as well as pure Al.…”

“…More recently increased research interest has been devoted to the fabricability as well as mechanical and physical properties of SLMed hypereutectic AlSi alloys using prealloyed powders [26][27][28] and powder mixtures [29][30][31], respectively. Kimura et al [27] investigated the densification behavior, mechanical properties and thermal conductivity for a range of prealloyed hypoeutectic, eutectic and hypereutectic AlSi alloys as well as pure Al. The energy input required to achieve optimum density scattered in a range of 50 J/mm 3 to 60 J/mm 3 for alloys containing more than 6 wt% Si and thermal conductivity was found to decrease with increasing Si content to a minimum of 105 W/m K for AlSi20.…”

Macro and nanoscale wear behaviour of Al-Al 2 O 3 nanocomposites fabricated by selective laser melting

“…The molten pool tracks after solidification were clear and intact without obvious porosity present, thus implying that alumina particulates showed good wetting ability and that dense parts could be produced under the process parameters that were employed. The as-fabricated sample showed a granular microstructure; the microstructure was considered to be that of aluminium caused by the rapid solidification due to the laser irradiation, as reported by Kimura et al [28]. Furthermore, the microstructure at the molten pool region showed different development; in that case, a relatively fine microstructure was observed within the molten pool as compared to the coarse microstructure found at the boundary regions of the molten pool ( Fig.…”

Fusion‐Based Additive Manufacturing for Processing Aluminum Alloys: State‐of‐the‐Art and Challenges

“…It is expected that a reduction of the Si content in Al–Si alloys would result in a wider solidification interval, and thus in a lesser A.M. processability . An hypoeutectic AlSi7Mg0.3 alloy has still been successfully fabricated by LBM, whereas AlSi alloys with a Si content lower than 4 wt% were found prone to the formation of microcracks during fabrication …”