Properties of Aluminium Alloys Produced by Selective Laser Melting

2016 ◽  
Vol 710 ◽  
pp. 83-88 ◽  
Author(s):  
Paola Bassani ◽  
Carlo Alberto Biffi ◽  
Riccardo Casati ◽  
Adrianni Zanatta Alarcon ◽  
Ausonio Tuissi ◽  
...  

Analysis of peculiar properties offered by Al alloys produced according to additive manufacturing techniques, specifically by Selective Laser Melting (SLM), is carried out. Two alloys are considered, derived by casting (AlSi10Mg) and by wrought (ENAW 2618) applications. The SLM processed samples are investigated considering their microstructural and mechanical properties after SLM and compared to cast and wrought counterparts. A strong microstructural refinement induced by SLM processing is observed for both alloys, resulting in excellent hardness properties. Investigation on integrity of samples revealed that small-size microvoids and unmelted regions could be present in SLM parts.

2021 ◽  
Vol 1016 ◽  
pp. 1611-1617
Author(s):  
Caroline Widomski ◽  
Denis Solas ◽  
François Brisset ◽  
Anne Laure Helbert ◽  
Thierry Baudin ◽  
...  

Selective laser melting (SLM) is one of the new additive manufacturing techniques in which complex parts can be created directly by selectively melting layers of powder. If the productivity of the process is too fast, defects (porosity, partially melted powder, spatters …) are generated inside the fabricated parts and can deteriorate the mechanical properties of the product. A new Laser Boost strategy with a larger melting area and a productivity of 43.20 cm3/h has been compared to a Linear Classic strategy. Ti-64 alloy samples were elaborated with both strategies to study their influence on microstructure and mechanical properties. Laser Boost strategy leads to the formation of Ti-64 prior β grains that are larger than the Linear Classic strategy. Mechanical properties obtains are similar with both strategies with a maximum strength average around 1250MPa and an elongation at failure between 3 and 9%. A thermal post-processing by Hot Isostatic Pressure have been carried out on samples made by Laser Boost to increase the ductility of the material up to 15%.


Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3603
Author(s):  
Tim Pasang ◽  
Benny Tavlovich ◽  
Omry Yannay ◽  
Ben Jakson ◽  
Mike Fry ◽  
...  

An investigation of mechanical properties of Ti6Al4V produced by additive manufacturing (AM) in the as-printed condition have been conducted and compared with wrought alloys. The AM samples were built by Selective Laser Melting (SLM) and Electron Beam Melting (EBM) in 0°, 45° and 90°—relative to horizontal direction. Similarly, the wrought samples were also cut and tested in the same directions relative to the plate rolling direction. The microstructures of the samples were significantly different on all samples. α′ martensite was observed on the SLM, acicular α on EBM and combination of both on the wrought alloy. EBM samples had higher surface roughness (Ra) compared with both SLM and wrought alloy. SLM samples were comparatively harder than wrought alloy and EBM. Tensile strength of the wrought alloy was higher in all directions except for 45°, where SLM samples showed higher strength than both EBM and wrought alloy on that direction. The ductility of the wrought alloy was consistently higher than both SLM and EBM indicated by clear necking feature on the wrought alloy samples. Dimples were observed on all fracture surfaces.


Author(s):  
Bilal Hussain ◽  
A. Sherif El-Gizawy

Selective Laser Melting (SLM) is one of the important Additive Manufacturing techniques for building functional products. Nevertheless, the absence of accurate models for predicting the SLM process behavior, delays development of cost effective and defects free process. This work presents a coupled thermo-mechanical numerical model to capture the two phase (solid-liquid) solidification melting phenomena that occur in the process. The proposed model will also predict the evolvement of process-induced properties and defects particularly residual stresses caused by temperature gradient and thermal stresses. CO2 or Nd:YAG laser beam can be used as a heat source with a Gaussian distribution for the laser beam energy.


Author(s):  
Xiaoqing Wang ◽  
Xibing Gong ◽  
Kevin Chou

This study presents a thorough literature review on the powder-bed laser additive manufacturing processes such as selective laser melting (SLM) of Inconel 718 parts. The paper first introduces the general aspects of powder-bed laser additive manufacturing and then discusses the unique characteristics and advantages of SLM. Moreover, the bulk of this study includes extensive discussions of microstructures and mechanical properties, together with the application ranges, of Inconel 718 parts fabricated by SLM.


Metals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 729 ◽  
Author(s):  
Wei Chen ◽  
Guangfu Yin ◽  
Zai Feng ◽  
Xiaoming Liao

Additive manufacturing by selective laser melting (SLM) was used to investigate the effect of powder feedstock on 316L stainless steel properties include microstructure, relative density, microhardness and mechanical properties. Gas atomized SS316L powders of three different particle size distribution were used in this study. Microstructural investigations were done by scanning electron microscopy (SEM). Tensile tests were performed at room temperatures. Microstructure characterization revealed the presence of hierarchical structures consisting of solidified melt pools, columnar grains and multiform shaped sub-grains. The results showed that the SLM sample from the fine powder obtained the highest mechanical properties with ultimate tensile strength (UTS) of 611.9 ± 9.4 MPa and yield strength (YS) of 519.1 ± 5.9 MPa, and an attendant elongation (EL) of 14.6 ± 1.9%, and a maximum of 97.92 ± 0.13% and a high microhardness 291 ± 6 HV0.1. It has been verified that the fine powder (~16 μm) could be used in additive manufacturing with proper printing parameters.


Author(s):  
Mohsen Taheri Andani ◽  
Christoph Haberland ◽  
Jason Walker ◽  
Mohammad Elahinia

It’s well accepted that the thermo-mechanical properties of Nitinol (NiTi) are strongly affected by the material processing. Additive manufacturing has been recently considered as an interesting technique to develop Nitinol devices with sophisticated geometries, which are impossible or very difficult to be produced through typical manufacturing procedures. In the present work, the effect of energy input on the phase transformation temperatures, as the most critical thermal parameters of the shape memory material, of Nitinol parts manufactured by selective laser melting is investigated and discussed.


2019 ◽  
Vol 818 ◽  
pp. 72-76 ◽  
Author(s):  
Konda Gokuldoss Prashanth ◽  
Sergio Scudino

Laser based powder bed fusion (LBPF) or selective laser melting (SLM) is making a leap march towards fabricating novel materials with improved functionalities. An attempt has been made here to fabricate hard quasicrystalline composites via SLM, which demonstrates that the process parameters can be used to vary the phases in the composites. The mechanical properties of the composite depend on their constituents and hence can be varied by varying the process parameters. The results show that SLM not only produces parts with improved functionalities and complex shape but also leads to defined phases and tunable properties.


2020 ◽  
Vol 112 (1-2) ◽  
pp. 175-192
Author(s):  
Mulla Ahmet Pekok ◽  
Rossitza Setchi ◽  
Michael Ryan ◽  
Quanquan Han ◽  
Dongdong Gu

AbstractSelective laser melting (SLM) offers significant benefits, including geometric freedom and rapid production, when compared with traditional manufacturing techniques. However, the materials available for SLM production remain limited, restricting the industrial adoption of the technology. The mechanical properties and microstructure of many aluminium alloys have not been fully explored, as their manufacturability using SLM is extremely challenging. This study investigates the effect of laser power, hatch spacing and scanning speed on the mechanical and microstructural properties of as-fabricated aluminium 2024 alloy (AA2024) manufactured using SLM. The results reveal that almost crack-free structures with high relative density (99.9%) and Archimedes density (99.7%) have been achieved. It is shown that when using low energy density (ED) levels, large cracks and porosities are a major problem, owing to incomplete fusion; however, small gas pores are prevalent at high-energy densities due to the dissolved gas particles in the melt pool. An inversely proportional relationship between ED and microhardness has also been observed. Lower ED decreases the melt pool size and temperature gradients but increases the cooling rate, creating a fine-grained microstructure, which restricts dislocation movement, therefore increasing the microhardness. The highest microhardness (116 HV0.2), which was obtained from one of the lowest EDs used (100 J/mm3), is 45% higher than as-cast AA2024-0, but 17% lower than wrought AA2024-T6 alloy.


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