The Production and Subsequent Selective Laser Melting of AlSi12 Powder

2017 ◽  
Vol 265 ◽  
pp. 434-438 ◽  
Author(s):  
P.A. Lykov ◽  
A.O. Shults ◽  
K.A. Bromer
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Selective Laser Melting ◽  
Gas Jet ◽  
Laser Melting ◽  
Size And Shape ◽  
Powder Particles ◽  
Scanning Electron

The paper studies the atomization of Al-based alloy AlSi12 in gas jet. Air was used as a spraying gas. The size and shape of powder particles were studied by using scanning electron microscopy and optical granulomorphometer. The obtained powder was used in selective laser melting.

scholarly journals The Effect of Building Direction on Microstructure and Microhardness during Selective Laser Melting of Ti6Al4V Titanium Alloy

2021 ◽  
Author(s):  
D. Palmeri ◽  
G. Buffa ◽  
G. Pollara ◽  
L. Fratini
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Titanium Alloy ◽  
Additive Manufacturing ◽  
Selective Laser Melting ◽  
Laser Melting ◽  
Ti6al4v Titanium Alloy ◽  
Mechanical Performances ◽  
Scanning Electron

AbstractDuring the last few years, additive manufacturing has been more and more extensively used in several industries, especially in the aerospace and medical device fields, to produce Ti6Al4V titanium alloy parts. During the Selective Laser Melting (SLM) process, the heterogeneity of finished product is strictly connected to the scan strategies and the building direction. An optimal managing of the latter parameters allows to better control and defines the final mechanical and metallurgical properties of parts. Acting on the building direction it is also possible to optimize the critical support structure. In particular, more support structures are needed for the sample at 0°, while very low support are required for the sample at 90°. To study the effects of build direction on microstructure heterogeneity evolution and mechanical performances of selective laser melted Ti6Al4V parts, two build direction samples (0°, 90°) were manufactured and analyzed using optical metallographic microscope (OM) and scanning electron microscopy (SEM). Isometric microstructure reconstruction and microhardness tests were carried out in order to analyze the specimens. The obtained results indicate that the build direction has to be considered a key geometrical parameter affecting the overall quality of the obtained products.

scholarly journals Microstructural Characterization of the Anisotropy and Cyclic Deformation Behavior of Selective Laser Melted AlSi10Mg Structures

Metals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 825 ◽  
Author(s):  
Mustafa Awd ◽  
Felix Stern ◽  
Alexander Kampmann ◽  
Daniel Kotzem ◽  
Jochen Tenkamp ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Selective Laser Melting ◽  
Microstructural Characterization ◽  
Fatigue Tests ◽  
Laser Melting ◽  
Structural Anisotropy ◽  
Scanning Electron

The laser-based fusion of metallic powder allows construction of components with arbitrary complexity. In selective laser melting, the rapid cooling of melt pools in the direction of the component building causes significant anisotropy of the microstructure and properties. The objective of this work is to investigate the influence of build anisotropy on the microstructure and mechanical properties in selective laser melted AlSi10Mg. The alloy is comprehensively used in the automotive industry and has been one of the most frequently investigated Al alloys in additive manufacturing. Using specimens produced in three different building orientations with respect to the build platform, the anisotropy of the microstructure and defects will be investigated using scanning electron microscopy and microcomputed tomography. The analysis showed a seven-times higher pore density for the 90°-specimen compared to the 0°-specimen. The scanning electron microscopy revealed the influence of the direction of the cooling gradient on the constitution of the eutectic phase. Mechanical properties are produced in quasi-static and fatigue tests of variable and constant loading amplitudes. Specimens of 0° showed 8% higher tensile strength compared to 90°-specimens, while fracture strain was reduced almost 30% for the 45°-specimen. The correlation between structural anisotropy and mechanical properties illustrates the influence of the building orientation during selective laser melting on foreseen fields of application.

Scanning Electron Microscopy and x-ray analysis of microparticles and early hydration effects

1995 ◽  
Vol 53 ◽  
pp. 692-693
Author(s):  
Yun Lu ◽  
David C. Joy
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
High Resolution ◽  
Morphological Development ◽  
Early Hydration ◽  
X Ray ◽  
Blended Cements ◽  
Powder Particles ◽  
Chemical Wastes ◽  
Scanning Electron

High resolution scanning electron microscopy (SEM) and energy dispersive x-ray analysis (EDXA) were performed to investigate microparticles in blended cements and their hydration products containing sodium-rich chemical wastes. The physical appearance of powder particles and the morphological development at different hydration stages were characterized by using high resolution SEM Hitachi S-900 and by SEM S-800 with a EDX spectrometer. Microparticles were dispersed on the sample holder and glued by 1% palomino solution. Hydrated bulk samples were dehydrated by acetone and mounted on the holder by silver paste. Both fracture surfaces and flat cutting sections of hydrating samples were prepared and examined. Some specimens were coated with an 3 nm thick Au-Pd or Cr layer to provide good conducting surfaces. For high resolution SEM S-900 observations the accelerating voltage of electrons was 1-2 KeV to protect the electron charging. Microchemical analyses were carried out by S800/EDS equipped with a LINK detector of take-off angle =40°.

Effect of Distance along the Built Axis on Mechanical Properties and Microstructure in Al10SiMg SLM Alloy

2021 ◽  
Vol 1016 ◽  
pp. 309-314
Author(s):  
Emanuela Cerri ◽  
Emanuele Ghio
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Mechanical Response ◽  
Property Values ◽  
Solution Treatment ◽  
Effect Of Temperature ◽  
Laser Melting ◽  
Precipitation Behaviour ◽  
Scanning Electron

It is know that rapid solidification promotes solid solubility larger than at equilibrium, in association with very fine grains and eutectic microstructures. Consequently, the precipitation behaviour in additive manufacturing alloys can be quite different from that of alloys quenched after a solution treatment and aged. In this study, Al10SiMg samples were produced by Selective Laser Melting (SLM) while keeping the table at 150°C continuously during the job. The effect of temperature on mechanical properties of the samples was investigated as function of time or distance along the built axis (300 mm). The hardness behaviour was measured by micro Vickers indentations and significant inhomogeneities were detected along the built axes. These results were also confirmed by tensile property values. The tensile strength varied of 80 MPa from the bottom to the top of the sample. The microstructure was investigated by optical and scanning electron microscopy; the observations showed variable precipitate distributions that justify the mechanical response along the built axis.

The Properties of Lattice Structures Manufactured Using Selective Laser Melting

2012 ◽  
Vol 445 ◽  
pp. 386-391 ◽  
Author(s):  
Y. Shen ◽  
W.J. Cantwell ◽  
Robert A.W. Mines ◽  
K. Ushijima
Keyword(s):  
Electron Microscopy ◽  
Selective Laser Melting ◽  
Research Study ◽  
Failure Mechanisms ◽  
Lattice Structures ◽  
Laser Melting ◽  
Tension Tests ◽  
Complex Architectures ◽  
Block Structures ◽  
Scanning Electron

This paper outlines the findings of an on-going research study investigating the properties of a range of steel and titanium-based micro-lattice structures manufactured using the selective laser melting (SLM) technique. Initially, tension tests have been conducted on strands manufactured at different build angles. Micro-lattice block structures, with struts oriented at +/-45o were then tested in compression at quasi-static rates of loading. The failure mechanisms have been investigated using both optical and scanning electron microscopy. These tests have highlighted the attractive properties offered by these complex architectures.

Description of the eggs of Psorophora ciliata and Psorophora ferox (Diptera: Culicidae, Aedini) from the east of the Brazilian state of Santa Catarina using scanning electron microscopy

Zootaxa ◽  
2018 ◽  
Vol 4442 (3) ◽  
pp. 485
Author(s):  
LUCAS ROSSITO DE CARVALHO ◽  
ELIANA MEDEIROS OLIVEIRA ◽  
CARLOS BRISOLA MARCONDES
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Regional Variation ◽  
Outer Edge ◽  
Internal Diameter ◽  
External Diameter ◽  
Santa Catarina ◽  
Size And Shape ◽  
Northern Regions ◽  
Scanning Electron

Scanning electron microscopy was used to examine and describe the egg of Psorophora ciliata, which was not previous adequately described, and the egg of Ps. ferox, which exhibited regional variation. Eggs of Ps. ciliata have long tubercles (length 26.7±1.72 µm) in the outer chorion, surrounded by a hexagonal reticulation. The micropyle (external diameter, to the outer edge of the collar, 26.59 µm; internal diameter 20.8 µm) is surrounded by an irregular collar with a thickness of 14.97 ±0.63 µm. Eggs of Ps. ferox exhibit some differences in the size and shape of tubercles compared to those from other more northern regions. 

Effect of maltodextrin reduction and native agave fructans addition on the physicochemical properties of spray-dried mango and pineapple juices

2018 ◽  
Vol 24 (6) ◽  
pp. 519-532 ◽  
Author(s):  
Darvin E Jimenez-Sánchez ◽  
Montserrat Calderón-Santoyo ◽  
Rosa I Ortiz-Basurto ◽  
Pedro U Bautista-Rosales ◽  
Juan A Ragazzo-Sánchez
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Storage Stability ◽  
Partial Replacement ◽  
Inlet Temperature ◽  
Drying Process ◽  
Spherical Powder ◽  
Powder Particles ◽  
Spray Dried ◽  
Scanning Electron

The effects of the partial replacement of maltodextrin by native agave fructans on the characteristics of spray-dried pineapple and mango powder were evaluated in this study. An experimental 33 design, three concentrations of maltodextrin (5, 7, and 10%), three concentrations of native agave fructans (0, 2, and 4%), and three feed temperatures (110, 115, and 120  ℃) were used. The results using the treatment in which only maltodextrin was used as a reference indicated that an increment in the inlet temperature decreases the moisture content, aw, and solubility. Likewise, an increase (more than 2%) in fructans concentration generates products with increased aw, moisture, hygroscopicity, wettability, and greater solubility. Additionally, no modification of storage stability was observed. Mango and pineapple powder color were affected mainly by the inlet temperature, causing an increase in luminosity (L*) and a decrease in parameter ( a*). A scanning electron microscopy showed spherical powder particles with certain contractions; powder stability in treatments with native agave fructans was not modified in the treatment at 2%. Finally, the addition of 2% agave fructans as carrier material was able to reduce the maltodextrin concentration of the spray drying process.

scholarly journals A Concept for Three-Dimensional Particle Metrology Based on Scanning Electron Microscopy and Structure-from-Motion Photogrammetry

2020 ◽  
Vol 125 ◽  
Author(s):  
Vipin N. Tondare
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Structure From Motion ◽  
3D Model ◽  
Three Dimensional ◽  
Sem Images ◽  
Shape Information ◽  
Size And Shape ◽  
Future Work ◽  
Scanning Electron

Scanning electron microscopy (SEM) has been frequently used for size and shape measurements of particles. SEM images offer two-dimensional (2D) information about a particle’s lateral dimensions. Unfortunately, information about the particle’s three-dimensional (3D) size and shape remains unavailable. To resolve this issue, I propose a new concept in SEM: 3D particle metrology obtained by applying structure-from-motion (SfM) algorithms to multiple rotational SEM images of particles deposited onto a cylindrical substrate to generate a 3D model from which size and shape information can be extracted. Particles can have any size that is suitable for SEM imaging. SEM images of the sample can be acquired from 0° to 360° using a rotational-tip SEM substage. Here, I will discuss the concept and, for clarity, illustrate it with aquarium gravel particles that are glued onto a craft roll and imaged optically before generating the 3D model of that handmade craft. Future work will include the experimental SEM realization, as well as further development of the SfM algorithms. In my view, this proposed concept may become an integral part of SEM-based particle metrology.

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