scholarly journals The Use of Selective Laser Melting to Increase the Performance of AlSi9Cu3Fe Alloy

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1918 ◽  
Author(s):  
Michaela Fousova ◽  
Drahomir Dvorsky ◽  
Marek Vronka ◽  
Dalibor Vojtech ◽  
Pavel Lejcek
Keyword(s):  
Electron Microscopy ◽  
Selective Laser Melting ◽  
Analytical Techniques ◽  
Static Tension ◽  
Laser Melting ◽  
Transmission Electron ◽  
Pressure Die Casting ◽  
First Time ◽  
Comprehensive Characterization

For the first time, the comprehensive characterization of the additively manufactured AlSi9Cu3Fe alloy is reported in this paper. Conventionally, the AlSi9Cu3(Fe) alloy is prepared by high-pressure die casting (HPDC), but this technology largely does not offer such opportunities as additive manufacturing (AM) does, especially in the design of new lightweight parts. In the present paper, testing samples were prepared by selective laser melting (SLM), one of the AM technologies, and characterized in terms of their microstructure (by means of light microscopy, scanning electron microscopy and transmission electron microscopy in combination with analytical techniques for evaluation of chemical and phase composition) and mechanical properties (static tension, compression, and hardness). All the characteristics were compared with the HPDC reference material. Our study showed an excellent improvement both in strength (374 ± 11 MPa compared to 257 ± 17 MPa) and plasticity (1.9 ± 0.2% compared to 1.2 ± 0.5%) of the material thanks to its very fine and distinctive microstructure.

scholarly journals Microstructure and Mechanical Properties of Carbides Reinforced Nickel Matrix Alloy Prepared by Selective Laser Melting

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4792
Author(s):  
Tian Xia ◽  
Rui Wang ◽  
Zhongnan Bi ◽  
Rui Wang ◽  
Peng Zhang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Selective Laser Melting ◽  
High Efficiency ◽  
Matrix Alloy ◽  
Tensile Tests ◽  
Laser Melting ◽  
Haynes 230 ◽  
Transmission Electron ◽  
Room Temperature Yield Strength ◽  
The Matrix

Selective laser melting was used to prepare the ceramic particles reinforced nickel alloy owing to its high designability, high working flexibility and high efficiency. In this paper, a carbides particles reinforced Haynes 230 alloy was prepared using SLM technology to further strengthen the alloy. Microstructures of the carbide particles reinforced Haynes 230 alloy were investigated using electron microscopy (SEM), electron probe microanalysis (EPMA) and transmission electron microscopy (TEM). Meanwhile, the tensile tests were carried out to determine the strengths of the composite. The results show that the microstructure of the composite consisted of uniformly distributed M23C6 and M6C type carbides and the strengths of the alloy were higher than the matrix alloy Haynes 230. The increased strengths of the carbide reinforced Haynes 230 alloy (room temperature yield strength 113 MPa increased, ~ 33.2%) can be attributed to the synergy strengthening including refined grain strengthening, Orowan strengthening and dislocation strengthening.

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.

Electron microscopy characterization of monoclinic SiAs precipitates in heavily As+-implanted silicon

1991 ◽  
Vol 6 (8) ◽  
pp. 1701-1710 ◽  
Author(s):  
A. Armigliato ◽  
A. Parisini
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Annealing Temperature ◽  
X Ray ◽  
Transmission Electron ◽  
Small Precipitate ◽  
Diffraction Patterns ◽  
Microscopy Characterization ◽  
First Time

Silicon wafers have been implanted with As+ ions at an energy of 100 keV and a dose of 1 × 1017 cm−2 and subsequently annealed at 1050°for 15 min. This results in a peak As concentration of 7 × 1021 cm−3, which is far beyond the solid solubility value of arsenic in silicon at this annealing temperature. Rod-like precipitates, dislocations, and small precipitate-like defects have been observed by transmission electron microscopy. From the analysis of several diffraction patterns taken on a number of rod-like particles at different tilt angles, it has been unambiguously found that they have the structure of the monoclinic SiAs compound previously reported in literature. The stoichiometry of the precipitates has been confirmed by x-ray microanalysis. To our knowledge, this is the first time that this SiAs phase is detected in As+-implanted silicon.

scholarly journals Fabrication of titanium based biphasic scaffold using selective laser melting and collagen immersion

2017 ◽  
Vol 3 (1) ◽  
Author(s):  
Swee Leong Sing ◽  
Shuai Wang ◽  
Shweta Agarwala ◽  
Florencia Edith Wiria ◽  
Thi Mai Hoa Ha ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Selective Laser Melting ◽  
Single Phase ◽  
Osteochondral Defects ◽  
Laser Melting ◽  
Two Phases ◽  
First Time ◽  
Biphasic Scaffolds

 Tissue engineering approaches have been adopted to address challenges in osteochondral tissue regeneration. Single phase scaffolds, which consist of only one single material throughout the whole structure, have been used extensively in these tissue engineering approaches. However, a single phase scaffold is insufficient in providing all the properties required for regeneration and repair of osteochondral defects. Biphasic scaffolds with two distinct phases of titanium/type 1 collagen and titanium-tantalum/type 1 collagen were developed for the first time using selective laser melting. Observation of the biphasic scaffolds demonstrated continuous interface between the two phases and mechanical characterization of the metallic scaffolds support the feasibility of the newly developed scaffolds for tissue engineering in osteochondral defects.

Synthesis and Characterization of Nanosized Manganese Oxyhydroxide Compounds by Sonochemical Method

2016 ◽  
Vol 35 (5) ◽  
pp. 493-498
Author(s):  
Masoud Salavati-Niasari ◽  
Mahdiyeh Esmaeili-Zare ◽  
Mina Gholami-Daghian ◽  
Samira Bagheri
Keyword(s):  
Electron Microscopy ◽  
Ultrasound Irradiation ◽  
Sonochemical Method ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Ft Ir ◽  
Manganese Oxyhydroxide ◽  
Average Size ◽  
First Time

AbstractManganese oxyhydroxide (MnOOH) nanoparticles were synthesized by the reaction of [Mn(Hsal)2] complex and NaOH in the presence of ultrasound irradiation. In this study, the effect of different reaction parameters such as type of solvent, sonication time and type of surfactant on the morphology and the particle size of product were studied. The as-synthesized nanoparticles, with an average size of 10–15 nm, were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectra (FT-IR) and energy dispersive spectrometry (EDS). To the best of author’s knowledge, it is the first time that [Mn(Hsal)2] complex is used as manganese source for the synthesis of MnOOH nanoparticles.

TEM characterization of metallization systems in VLSI

1991 ◽  
Vol 49 ◽  
pp. 818-819
Author(s):  
A. Mitwalsky ◽  
H. Oppolzer
Keyword(s):  
Electron Microscopy ◽  
Cross Sections ◽  
High Spatial Resolution ◽  
Analytical Techniques ◽  
Detailed Knowledge ◽  
Tem Characterization ◽  
Transmission Electron ◽  
Device Operation ◽  
Scanning Electron

Detailed knowledge of the properties of metallization systems used in silicon VLSI technolgy is essential to evaluate application and to achieve stable device operation. The progressively shrinking device dimensions require analytical techniques allowing to detect interfacial reactions or precipitation with nanometer resolution, particularly for the development of new processes. Transmission electron microscopy (TEM) of thin cross sections represents a powerful tool for obtaining such information directly. In addition to imaging analytical TEM allows phase and element identification with high spatial resolution.The interaction during processing between silicides of various metals (Ti, Co, Ta and W) and different dopants (B, As) in silicon was investigated since possible metal dopant reactions may lead to dopant depletion in the silicon. In the case of Ti and Ta silicide the formation of metal dopant compounds during heat treatment was indeed observed by scanning electron microscopy and TEM.

scholarly journals Estimation, morphometry and ultrastructure of ovarian preantral follicle population in agouti (Dasyprocta leporina)

2018 ◽  
Vol 38 (1) ◽  
pp. 175-182 ◽  
Author(s):  
Erica A.A. Santos ◽  
Gabriela L. Lima ◽  
Erica C.G. Praxedes ◽  
Andréia M. Silva ◽  
Keilla M. Maia ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Ultrastructural Analysis ◽  
Preantral Follicle ◽  
Transmission Electron ◽  
The Mean ◽  
First Time ◽  
Further Development

ABSTRACT: The aim of this study was to characterize the preantral ovarian follicular population in agoutis (D. leporina) by estimating the number of follicles at each developmental category, and also describe the morphometry and the specific features of the follicle and the oocyte by using light and transmission electron microscopy. The length of each ovary was measured using a caliper rule, longitudinally sectioned into two halves and both were immediately fixed to perform the estimation of follicular population and ultrastructural analysis. The mean (±S.E.M.) population of follicular per pair of ovary was estimated at 4419.8±532.26 and 5397.52±574.91 for right and left ovaries, respectively, but no differences were observed between them. The diameters for follicles, oocyte and nuclei were: 18.62±3.40μm, 12.28±2.37μm and 6.10±0.93μm for primordial, 23.75±5.70μm, 14.22±3.00μm and 6.70±1.24μm for primary and 88.55±17.61μm, 52.85±17.56μm and 22.33±17.61μm for secondary follicles, respectively. The most of the follicles found belonged to the primordial category (86.63%), followed by primary (13.01%) and secondary (0.35%) one. Additionally, polyovular follicles were observed in all the animals and they represented 7.51% of the total follicles counted. The ultrastructural analysis showed that the oocyte presented a central and regular nuclei, displaying a homogenous mass. Among the organelles, the mitochondria were the most abundant and the oocyte Golgi apparatus was rarely observed. In conclusion, this work shows for the first time the characterization of the population of preantral follicles in the ovary of Dasyprocta leporina. Those information will be useful for further development and adaptation of biotechniques such as germplasm cryopreservation and in vitro gametes manipulation.

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