Influence of processing conditions on strut structure and compressive properties of cellular lattice structures fabricated by selective laser melting
Chunlei Qiu,Sheng Yue,Sheng Yue,Nicholas J.E. Adkins,Mark Ward,Hany Hassanin,Peter D. Lee,Peter D. Lee,Philip J. Withers,Moataz M. Attallah +9 more
TLDR
In this article, the as-fabricated strut size, morphology and internal porosity were investigated using optical microscopy, scanning electron microscopy (SEM) and X-ray microtomography (micro-CT) and correlated to the compressive properties of the structure.Abstract:
AlSi10Mg cellular lattice structures have been fabricated by selective laser melting (SLM) using a range of laser scanning speeds and powers. The as-fabricated strut size, morphology and internal porosity were investigated using optical microscopy (OM), scanning electron microscopy (SEM) and X-ray microtomography (micro-CT) and correlated to the compressive properties of the structure. Strut diameter was found to increase monotonically with laser power while the porosity was largest at intermediate powers. Laser scanning speed was found to thicken the struts only at slow rates while the porosity was largest at intermediate speeds. High speed imaging showed the melt pool to be larger at high laser powers. Further the melt pool shape was found to vary cyclically over time, steadily growing before becoming increasingly instable and irregularly shaped before abruptly falling in size due to splashing of molten materials and the process repeating. Upon compressive loading, lattice deformation was homogeneous prior to the peak stress before falling sharply due to the creation of a (one strut wide) shear band at around 45° to the compression axis. The specific yield strength expressed as the yield stress/(yield stress of the aluminium × relative density) is not independent of processing conditions, suggesting that further improvements in properties can be achieved by process optimisation. Lattice struts failed near nodes by a mixture of ductile and brittle fracture.read more
Citations
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Journal ArticleDOI
3D printing of Aluminium alloys: Additive Manufacturing of Aluminium alloys using selective laser melting
Nesma T. Aboulkhair,Marco Simonelli,Luke Parry,Ian Ashcroft,Christopher Tuck,Richard J.M. Hague +5 more
TL;DR: A comprehensive understanding of the interrelation between the various aspects of the subject, as this is essential to demonstrate credibility for industrial needs, is presented in this paper, which highlights some key topics requiring attention for further progression.
Journal ArticleDOI
On the role of melt flow into the surface structure and porosity development during selective laser melting
Chunlei Qiu,Chinnapat Panwisawas,Mark Ward,Hector Basoalto,Jeffery Brooks,Moataz M. Attallah +5 more
TL;DR: In this paper, the development of surface structure and porosity of Ti-6Al-4V samples fabricated by selective laser melting under different laser scanning speeds and powder layer thicknesses has been studied and correlated with the melt flow behavior through both experimental and modelling approaches.
Journal ArticleDOI
Effect of heat treatment on AlSi10Mg alloy fabricated by selective laser melting: Microstructure evolution, mechanical properties and fracture mechanism
TL;DR: In this paper, the influence of solution and artificial aging heat treatments on the microstructures and mechanical properties of SLM-produced AlSi10Mg alloy parts was investigated.
Journal ArticleDOI
In situ X-ray imaging of defect and molten pool dynamics in laser additive manufacturing
Chu Lun Alex Leung,Sebastian Marussi,Robert Atwood,Michael Towrie,Philip J. Withers,Peter D. Lee +5 more
TL;DR: A mechanism map for predicting the evolution of melt features, changes in melt track morphology from a continuous hemi-cylindrical track to disconnected beads with decreasing linear energy density and improved molten pool wetting with increasing laser power is developed.
Journal ArticleDOI
The microstructure and mechanical properties of selectively laser melted AlSi10Mg: The effect of a conventional T6-like heat treatment
TL;DR: In this paper, the nano-, micro-, and macro-scale mechanical properties of selective laser melting (SLM) AlSi10Mg were examined and correlated to the generated microstructure.
References
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A study of the microstructural evolution during selective laser melting of Ti–6Al–4V
TL;DR: In this article, the development of the microstructure of the Ti-6Al-4V alloy processed by selective laser melting (SLM) was studied by light optical microscopy.
Journal ArticleDOI
Fine-structured aluminium products with controllable texture by selective laser melting of pre-alloyed AlSi10Mg powder
TL;DR: In this paper, the high thermal gradients occurring during SLM lead to a very fine microstructure with submicron-sized cells, which can be modified to a weak cube texture along the building and scanning directions when a rotation of 90° of the scanning vectors within or between the layers is applied.