scholarly journals Effects processing parameters and building orientation on the microstructural and mechanical properties of AlSilOMg parts printed by selective laser melting

2021 ◽  
Vol 121 (7) ◽  
Author(s):  
C. Phetolo ◽  
V. Matjeke ◽  
J. van der Merwe
Keyword(s):  
Mechanical Properties ◽  
Selective Laser Melting ◽  
Processing Parameters ◽  
Fractographic Analysis ◽  
Lower Percentage ◽  
Laser Melting ◽  
Scanning Calorimetry ◽  
Two Phase ◽  
Homogeneous Microstructure ◽  
Building Orientation

SYNOPSIS The mechanical properties and microstructure of AlSilOMg alloy samples that were printed by selective laser melting (SLM) were studied to determine the effect of processing parameters and building orientation. After printing, the alloy was stress relieved at 250°C for 2 hours. The microstructures were analysed by optical microscopy and scanning electron microscopy (SEM) to determine the alloy phases and distribution. Phase transformation characteristics of the material were evaluated using differential scanning calorimetry (DSC). Mechanical properties were determined by subjecting the XY- and Z-built samples to tensile and nano-indentation testing. The samples from the tensile tests were then used to perform fractographic analysis by SEM. The microstructural properties in each orientation revealed a non-homogeneous microstructure which was characterized by a semi-elliptical tract and fine silicon precipitates, which were found to be softer along the fusion zone. The DSC thermograms revealed that the material underwent two phase transformations during the first heating cycle. The mechanical properties revealed a higher UTS, higher yield strength, and a lower percentage elongation in the Z orientation than in the XY orientation. Fractographic analysis showed that crack initiation in both orientations started from the surface in a brittle manner due to surface flows, and then propagated via microvoid coalescence. Keywords: AlSi10Mg alloy, additive manufacturing, mechanical propeerties, microstructure.

scholarly journals Densification, Microstructure, and Mechanical Properties of Additively Manufactured 2124 Al–Cu Alloy by Selective Laser Melting

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4423
Author(s):  
Junwang Deng ◽  
Chao Chen ◽  
Wei Zhang ◽  
Yunping Li ◽  
Ruidi Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Selective Laser Melting ◽  
Hollow Structure ◽  
Base Plate ◽  
Scanning Speed ◽  
Processing Parameters ◽  
Laser Melting ◽  
Cu Alloy ◽  
Microstructure And Mechanical Properties ◽  
Hatch Spacing

Owing to its high specific strength and low density, Al–Cu alloys have been extensively used in aerospace for lightweight components. Additive manufacturing techniques such as selective laser melting, which offers geometric freedom, is suitable for topology-optimized designs. In this study, the effect of processing parameters on the densification, microstructure, and mechanical properties of additively manufactured Al–Cu alloy 2124 by selective laser melting was investigated. Parameters such as laser power, scanning speed, hatch spacing, and use of a support were studied. The results revealed that a grille support with a hollow structure played a resistant role in the transfer of heat to the base plate, thus reducing the temperature gradient and lessening cracks in the building part. Smaller hatch spacing was beneficial for the achievement of a higher relative density and strength due to track re-melting and liquid phase backflow, which could fill cracks and pores during the building process. An ultimate tensile strength as high as 300 MPa of the vertically built sample was obtained at optimized processing parameters, while the elongation was relatively limited. Moreover, columnar grains were found to be responsible for the anisotropy of the mechanical properties of the as-printed 2124 alloy.

Selective laser melting (SLM) of pure gold for manufacturing dental crowns

2014 ◽  
Vol 20 (6) ◽  
pp. 471-479 ◽  
Author(s):  
Mushtaq Khan ◽  
Phill Dickens
Keyword(s):  
Mechanical Properties ◽  
Layer Thickness ◽  
Surface Quality ◽  
Selective Laser Melting ◽  
Processing Parameters ◽  
Pure Gold ◽  
Laser Melting ◽  
Content Type ◽  
Dental Crowns ◽  
Suitable Processing

Purpose – This paper aims to present the application aspect of the work to manufacturing premolar and molar dental crowns by selective laser melting (SLM) of pure gold. Over the years different metals have been processed using laser-based Additive Manufacturing processes, but very little work has been published on the SLM of gold (Au). Previously published work presented suitable processing parameters for SLM of pure gold. Design/methodology/approach – Suitable processing parameters were used to manufacture premolar and molar dental crowns using SLM system. Different layer thickness was used to analyse the effect on surface quality of crowns. Mechanical properties are checked using nanoindentation and micro Computerized Tomography scanning. Findings – Dental crowns were successfully manufacturing using new build platform and suitable processing parameters. Parts were manufacturing using minimal supports which prevented parts from damaging during removal. A bed temperature of 100°C was found suitable for reducing warpage in the layers. Layer thickness of 50μm was found to have better surface quality and structural integrity as compared to 75μm. Porosity was found to be predominantly inter-layer. Small difference in mechanical properties of dental crowns is associated with the laser processing. Originality/value – This research is the first of its kind which presents dental crown manufacturing using SLM of pure gold.

Selective laser melting additive manufacturing of in situ Al2Si4O10/Al composites: Microstructural characteristics and mechanical properties

2016 ◽  
Vol 51 (4) ◽  
pp. 519-532 ◽  
Author(s):  
Jiubin Jue ◽  
Dongdong Gu
Keyword(s):  
Mechanical Properties ◽  
Selective Laser Melting ◽  
Processing Parameters ◽  
Dry Sliding Wear ◽  
Microstructural Development ◽  
Laser Melting ◽  
Composite Powders ◽  
Wear Performance ◽  
Al Matrix

The advanced selective laser melting technology was employed to prepare in situ Al based composites. Relationship among selective laser melting processing parameters, microstructures and resultant mechanical properties had been established. It turned out that in situ Al2Si4O10/Al composites were successfully fabricated by selective laser melting of Al2O3/AlSi10Mg composite powders. Due to the overlap between neighboring tracks and the remelting of previously solidified layers, two distinguished zones consisting of track core and track overlap were produced in laser induced melt pool. The two zones, respectively experienced different thermal histories, thus leading to the variation of cooling rate, which had a significant influence on the microstructural development and resultant mechanical performances. The track core mainly consisted of remarkably refined cellular dendritic Al matrix decorated with uniformly distributed ring-structured Al2Si4O10 reinforcements, while the track overlap was characterized with comparatively coarse columnar dendritic Al matrix as well as the coarse Al2Si4O10 reinforcements. At the optimal v of 500 mm/s, the obtained dynamic nanohardness ( H d) of track core ( H d = 3.79 GPa) and track overlap ( H d = 3.52 GPa) for selective laser melting processed composites part both showed tremendous enhancement upon that of unreinforced Al part ( H d = 0.58 GPa). The dry sliding wear tests indicated that the optimally prepared Al2Si4O10/Al composites part exhibited excellent wear performance with a considerably low coefficient of friction of 0.32 and a significantly reduced wear rate of 4.52 × 10−5 mm3 N−1 m−1. The formed consecutive protective adherent tribolayer on the worn surface and the significantly enhanced hardness of the composites well accounted for the superior wear performance.

Microstructural and Mechanical Properties of Selective Laser Melted Al 4047

2015 ◽  
Vol 752-753 ◽  
pp. 485-490 ◽  
Author(s):  
Shafaqat Siddique ◽  
Eric Wycisk ◽  
Gerrit Frieling ◽  
Claus Emmelmann ◽  
Frank Walther
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Selective Laser Melting ◽  
Process Parameters ◽  
Processing Parameters ◽  
Complex Geometries ◽  
Optimal Parameters ◽  
Post Processing ◽  
Laser Melting ◽  
Process Cost

Selective laser melting (SLM) has been recognized as a pertinent process for manufacturing of complex geometries. Al 4047 has been manufactured in this study with different processing parameters of the SLM process to obtain the optimal parameters suitable for required applications, as well as to determine the effect of these parameters and post-processing heat treatment on mechanical properties. A unique Al-Si eutectic microstructure is obtained with Al dendrites growing in the scanning direction. Mechanical properties of the SLM manufactured Al 4047 are at par with those of conventionally manufactured alloy. These properties can be varied by changing the SLM process parameters which can help controlling the process cost depending upon required mechanical properties.

Sign in / Sign up

Export Citation Format

Share Document