Compression Behavior of Diamond Lattice Structure and Its Hall–Petch Relationship

2020 ◽  
pp. 2001024
Author(s):  
Yefeng Chen ◽  
Hang Liu ◽  
Jiawei Shen ◽  
Jianming Gong ◽  
Jiaxi Zhao
Keyword(s):  
Lattice Structure ◽  
Diamond Lattice ◽  
Compression Behavior ◽  
Petch Relationship

Fabrication of Diamond Photonic Crystals with Oxide and Metallic Glasses Lattices for Terahertz Wave Control by Micro Pattering Stereolithography

2013 ◽  
Vol 2013 (CICMT) ◽  
pp. 000099-000104
Author(s):  
Soshu Kirihara ◽  
Maasa Nakano
Keyword(s):  
Photonic Crystals ◽  
Metallic Glass ◽  
Lattice Structure ◽  
Dielectric Materials ◽  
Diamond Lattice ◽  
Bragg Diffraction ◽  
Oxide Glass ◽  
Layer By Layer ◽  
Terahertz Time Domain Spectroscopy ◽  
Micro Patterning

Diamond lattice type photonic crystals with periodic arranged magnetic and dielectric materials can reflect the terahertz waves through Bragg diffraction. The fine diffraction lattices were fabricated successfully by using micro patterning stereolithography of computer aided designing and manufacturing methods. In this process, the photo sensitive acrylic resin paste mixed with micrometer sized metallic glass and oxide glass particles was spread on a glass substrate with 10 μm in layer thickness by using a mechanical knife edge, and cross sectional images of ultra violet ray were exposed with 2 μm in part accuracy. The high resolution exposure could be realized by using a digital micro-mirror device. The micro mirrors of 14 μm in edge length were tilted individually by piezoelectric actuators. Through the layer by layer stacking, the micrometer order metallic glass and oxide glass composite structure was formed. The magnetic and dielectric composite lattices could be obtained through the dewaxing and sintering process with the lower temperature of 400 ºC under the transition point of metallic glass and above the melting point of oxide glass. The amorphous structure formation after the heat treatment was verified by a X-ray diffraction analysis. A transmission spectrum of electromagnetic wave in terahertz frequency ranges for the formed magnetic and dielectric crystals with a diamond lattice structure was measured by using a terahertz time domain spectroscopy.

Compression behavior of selected laser melted Al/quasicrystal composite lattice structure

2019 ◽  
Vol 31 (2) ◽  
pp. 022311
Author(s):  
N. Kang ◽  
X. Lin ◽  
J. Xu ◽  
D. Joguet ◽  
Q. Li ◽  
...  
Keyword(s):  
Lattice Structure ◽  
Compression Behavior ◽  
Composite Lattice

scholarly journals Mechanical Properties of Optimized Diamond Lattice Structure for Bone Scaffolds Fabricated via Selective Laser Melting

Materials ◽  
2018 ◽  
Vol 11 (3) ◽  
pp. 374 ◽  
Author(s):  
Fei Liu ◽  
David Zhang ◽  
Peng Zhang ◽  
Miao Zhao ◽  
Salman Jafar
Keyword(s):  
Mechanical Properties ◽  
Selective Laser Melting ◽  
Lattice Structure ◽  
Diamond Lattice ◽  
Laser Melting ◽  
Bone Scaffolds

scholarly journals A Kind of Filling Lattice Structure Based on DFAM for Mechanical Parts: The Diamond Lattice Structure

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Xuan Yin ◽  
Wenjun Meng ◽  
Jinzhao Cheng ◽  
Hailong Wang ◽  
Xiaoxia Zhao
Keyword(s):  
Mathematical Model ◽  
Additive Manufacturing ◽  
Lattice Structure ◽  
Variable Density ◽  
Diamond Lattice ◽  
Compression Tests ◽  
Compression Performance ◽  
Mechanical Parts ◽  
Equivalent Modulus ◽  
The Mathematical Model

Thanks to the geometric and material complexity of additive manufacturing, the design space of mechanical parts has been developed, in which lattice filling structure customization can be applied to the solid filling of mechanical parts to achieve the goal of mechanical structure lightweight. A kind of diamond lattice structure unit is designed by imitating the natural method based on Design for Additive Manufacturing of mechanical parts. The mathematical model of the relative density and mechanical properties of the unit are established, and the relationship between the two is obtained, which is verified by simulations; then the relatively uniform results are obtained. The variable density hypothesis of diamond lattice structure is proposed, the methods of simulations and compression tests are used to verify the hypothesis, and the results show that the variable density structure with the density of the filling element decreasing gradually with the stress point as the center has better compression performance and concurrently verify the correctness and applicability of the equivalent modulus of elasticity mathematical model. The results of this study can be applied to the solid sandwich filling of pressure mechanical parts, and the stress density matching relationship can be carried out to further specific design.

scholarly journals The Stability of a Nanoparticle Diamond Lattice Linked by DNA

Nanomaterials ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 661 ◽  
Author(s):  
Hamed Emamy ◽  
Oleg Gang ◽  
Francis W. Starr
Keyword(s):  
Free Energy ◽  
Self Assembly ◽  
Lattice Structure ◽  
Diamond Lattice ◽  
Structure Stability ◽  
Lattice Stability ◽  
Wulff Construction ◽  
Crystallite Shape ◽  
The Stability ◽  
Relative Gibbs Free Energy

The functionalization of nanoparticles (NPs) with DNA has proven to be an effective strategy for self-assembly of NPs into superlattices with a broad range of lattice symmetries. By combining this strategy with the DNA origami approach, the possible lattice structures have been expanded to include the cubic diamond lattice. This symmetry is of particular interest, both due to the inherent synthesis challenges, as well as the potential valuable optical properties, including a complete band-gap. Using these lattices in functional devices requires a robust and stable lattice. Here, we use molecular simulations to investigate how NP size and DNA stiffness affect the structure, stability, and crystallite shape of NP superlattices with diamond symmetry. We use the Wulff construction method to predict the equilibrium crystallite shape of the cubic diamond lattice. We find that, due to reorientation of surface particles, it is possible to create bonds at the surface with dangling DNA links on the interior, thereby reducing surface energy. Consequently, the crystallite shape depends on the degree to which such surface reorientation is possible, which is sensitive to DNA stiffness. Further, we determine dependence of the lattice stability on NP size and DNA stiffness by evaluating relative Gibbs free energy. We find that the free energy is dominated by the entropic component. Increasing NP size or DNA stiffness increases free energy, and thus decreases the relative stability of lattices. On the other hand, increasing DNA stiffness results in a more precisely defined lattice structure. Thus, there is a trade off between structure and stability of the lattice. Our findings should assist experimental design for controlling lattice stability and crystallite shape.

Compression behavior of three-dimensional printed polymer lattice structures

2018 ◽  
Vol 233 (8) ◽  
pp. 1574-1584 ◽  
Author(s):  
Mohammed Al Rifaie ◽  
Ahsan Mian ◽  
Raghavan Srinivasan
Keyword(s):  
Energy Absorption ◽  
Lattice Structure ◽  
Three Dimensional ◽  
Unit Cell ◽  
The Body ◽  
Basic Unit ◽  
Lattice Structures ◽  
Body Centered Cubic ◽  
Static Compression ◽  
Compression Behavior

This paper focuses on the compression behavior of additively manufactured or three-dimensional printed polymer lattice structures of different configurations. The body-centered cubic lattice unit cell, which has been extensively investigated for energy absorption applications, is the starting point for this research. In this study, the lattice structure based on the body-centered cubic unit cell was modified by adding vertical struts in different arrangements to create three additional configurations. Four lattice structure designs were selected for comparison: the basic unit cell (body centered cubic), body centered cubic with vertical struts added to all nodes in the lattice, body centered cubic with vertical struts added to alternate nodes in the lattice, and body centered cubic with gradient in the number of vertical bars in the lattice. Samples of all four designs were prepared using acrylonitrile–butadiene–styrene polymer by three-dimensional printing. The stiffness, failure loads, and energy absorption behaviors of all four configurations were determined under quasi-static compression loading. Specific properties were calculated by normalizing the test properties by the sample mass. It is observed from experimental data that selective placement of vertical support struts in the unit cell influences both the absolute and specific mechanical properties of lattice structures.

The dislocation structure of a 10° [110] tilt boundary in silicon

1983 ◽  
Vol 41 ◽  
pp. 114-115
Author(s):  
B. Cunningham ◽  
D.G. Ast
Keyword(s):  
Dislocation Structure ◽  
Tilt Angle ◽  
Imaging Technique ◽  
Diamond Lattice ◽  
Tilt Boundary ◽  
Formation Mechanisms ◽  
Diffraction Contrast ◽  
Lattice Fringe ◽  
Tilt Boundaries ◽  
Chemically Vapor Deposited

There have Been a number of studies of low-angle, θ < 4°, [10] tilt boundaries in the diamond lattice. Dislocations with Burgers vectors a/2<110>, a/2<112>, a<111> and a<001> have been reported in melt-grown bicrystals of germanium, and dislocations with Burgers vectors a<001> and a/2<112> have been reported in hot-pressed bicrystals of silicon. Most of the dislocations were found to be dissociated, the dissociation widths being dependent on the tilt angle. Possible dissociation schemes and formation mechanisms for the a<001> and a<111> dislocations from the interaction of lattice dislocations have recently been given.The present study reports on the dislocation structure of a 10° [10] tilt boundary in chemically vapor deposited silicon. The dislocations in the boundary were spaced about 1-3nm apart, making them difficult to resolve by conventional diffraction contrast techniques. The dislocation structure was therefore studied by the lattice-fringe imaging technique.

Structural analysis of the photosynthetic membrane from Ectothiorhodospira halochloris

1983 ◽  
Vol 41 ◽  
pp. 740-741
Author(s):  
H. Engelhardt ◽  
R. Guckenberger ◽  
W. Baumeister
Keyword(s):  
Lattice Structure ◽  
Bacterial Species ◽  
Hexagonal Lattice ◽  
Reaction Centre ◽  
Photosynthetic Membrane ◽  
Rhodopseudomonas Viridis ◽  
Photosynthetic Membranes ◽  
Ectothiorhodospira Halochloris ◽  
Main Components

Bacterial photosynthetic membranes contain, apart from lipids and electron transport components, reaction centre (RC) and light harvesting (LH) polypeptides as the main components. The RC-LH complexes in Rhodopseudomonas viridis membranes are known since quite seme time to form a hexagonal lattice structure in vivo; hence this membrane attracted the particular attention of electron microscopists. Contrary to previous claims in the literature we found, however, that 2-D periodically organized photosynthetic membranes are not a unique feature of Rhodopseudomonas viridis. At least five bacterial species, all bacteriophyll b - containing, possess membranes with the RC-LH complexes regularly arrayed. All these membranes appear to have a similar lattice structure and fine-morphology. The lattice spacings of the Ectothiorhodospira haloohloris, Ectothiorhodospira abdelmalekii and Rhodopseudomonas viridis membranes are close to 13 nm, those of Thiocapsa pfennigii and Rhodopseudomonas sulfoviridis are slightly smaller (∼12.5 nm).

Electron-Channelling Patterns: Principles and Techniques

1976 ◽  
Vol 34 ◽  
pp. 400-401
Author(s):  
David C. Joy
Keyword(s):  
Crystal Structure ◽  
Electron Flux ◽  
Lattice Structure ◽  
Incident Beam ◽  
Bloch Wave ◽  
Crystalline Solid ◽  
Angle Of Incidence ◽  
Electron Channelling ◽  
Regular Arrangement ◽  
Backscattered Signals

In a crystalline solid the regular arrangement of the lattice structure influences the interaction of the incident beam with the specimen, leading to changes in both the transmitted and backscattered signals when the angle of incidence of the beam to the specimen is changed. For the simplest case the electron flux inside the specimen can be visualized as the sum of two, standing wave distributions of electrons (Fig. 1). Bloch wave 1 is concentrated mainly between the atom rows and so only interacts weakly with them. It is therefore transmitted well and backscattered weakly. Bloch wave 2 is concentrated on the line of atom centers and is therefore transmitted poorly and backscattered strongly. The ratio of the excitation of wave 1 to wave 2 varies with the angle between the incident beam and the crystal structure.

Microstructural Study of Diamond Deformed Under High Pressure and Temperature

1985 ◽  
Vol 43 ◽  
pp. 230-231
Author(s):  
E. F. Koch
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Lattice Structure ◽  
Diamond Particle ◽  
Polycrystalline Diamond ◽  
Sintering Process ◽  
Ion Milling ◽  
Sintered Compact ◽  
Transmission Electron ◽  
High Pressure Sintering

Because of the extremely rigid lattice structure of diamond, generating new dislocations or moving existing dislocations in diamond by applying mechanical stress at ambient temperature is very difficult. Analysis of portions of diamonds deformed under bending stress at elevated temperature has shown that diamond deforms plastically under suitable conditions and that its primary slip systems are on the ﹛111﹜ planes. Plastic deformation in diamond is more commonly observed during the high temperature - high pressure sintering process used to make diamond compacts. The pressure and temperature conditions in the sintering presses are sufficiently high that many diamond grains in the sintered compact show deformed microtructures.In this report commercially available polycrystalline diamond discs for rock cutting applications were analyzed to study the deformation substructures in the diamond grains using transmission electron microscopy. An individual diamond particle can be plastically deformed in a high pressure apparatus at high temperature, but it is nearly impossible to prepare such a particle for TEM observation, since any medium in which the diamond is mounted wears away faster than the diamond during ion milling and the diamond is lost.

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