TEM analyses of in situ presolar grains in pristine matrix material of ordinary chondrite Semarkona

The low Z metal aluminium is a potential matrix material for the first wall in fusion reactors. A drawback in the application of A1 is the rel= atively high amount of He produced in it under fusion reactor conditions. Knowledge about the behaviour of He during irradiation and deformation in Al, especially near the surface, is therefore important.Using the TEM we have studied Al disks of 3 mm diameter and 0.2 mm thickness, which were perforated at the centre by double jet polishing. These disks were bombarded at∽200°C to various doses with α-particles, impinging at any angle and energy up to 1.5 MeV at both surfaces. The details of the irradiations are described in Ref.1. Subsequent observation indicated that in such specimens uniformly distributed He-bubbles are formed near the surface in a layer several μm thick (Fig.1).After bombardment the disks were deformed at 20°C during observation by means of a tensile device in a Philips EM 300 microscope.

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Initial Stages of InAs Quantum Dots Evolution in GaAs/AlAs Matrixes

MRS Proceedings ◽

10.1557/proc-749-w13.8 ◽

2002 ◽

Vol 749 ◽

Author(s):

Michael Yakimov ◽

Vadim Tokranov ◽

Alex Katnelson ◽

Serge Oktyabrsky

Keyword(s):

Quantum Dots ◽

Direct Evidence ◽

Matrix Material ◽

Single Layer ◽

High Energy ◽

Inas Quantum Dots ◽

Auger Signal ◽

The Matrix ◽

Growth Evolution

ABSTRACTWe have studied the first phases of post-growth evolution of InAs quantum dots (QDs) using in-situ Auger electron spectroscopy in conjunction with Reflection High Energy Electron Diffraction (RHEED). Direct evidence for InAs intermixing with about 6ML (monolayers) of the matrix material is found from Auger signal behavior during MBE overgrowth of InAs nanostructures. Re-establishment of 2D growth mode by overgrowth with GaAs or AlAs was monitored in single-layer and multi-layer QD structures using RHEED. Decay process of InAs QDs on the surface is found to have activation energy of about 1.1 eV that corresponds to In intermixing with the matrix rather than evaporation from the surface.

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Fabrication and characterization of TiB2-reinforced functionally graded aluminum matrix material

Industrial Lubrication and Tribology ◽

10.1108/ilt-12-2019-0538 ◽

2020 ◽

Vol 72 (10) ◽

pp. 1147-1152

Author(s):

Ömer Savaş

Keyword(s):

Wear Rate ◽

Abrasive Wear ◽

Peer Review ◽

Centrifugal Force ◽

Matrix Material ◽

Aluminum Matrix ◽

Functionally Graded ◽

Aluminum Matrix Composites ◽

Content Type

Purpose This study aims to investigate the production and abrasive wear rate of functionally graded TiB2/Al composites. TiB2 particles have been spontaneously formed in liquid matrix using in situ technique. The properties of composites such as hardness, abrasive wear rate and microstructure have been examined. Design/methodology/approach In situ TiB2 reinforcement phase was synthesized by using a liquid Al–Ti–B system. A semi-solid composite (Al(l)-TiB2(s)) prepared at 900°C was solidified under a centrifugal force to both grade functionally and give the final shape to materials. Abrasive wear test of materials was conducted using the pin-on-disk method at room temperature. The wear tests were carried out with two different loads of 1 Newton (N) and 2 N, a sliding velocity of 3.5 m s−1 and a sliding distance of 75 m. Findings This research provided the following findings; TiB2 particles can be successfully synthesized with in situ reaction technique in molten aluminum. It was determined that abrasive wear rate increases with increasing load and decreases with increasing TiB2 reinforcement content within matrix. Originality/value In previous studies, there have been many trials on the in situ production of TiB2-reinforced aluminum matrix composites. However, there are few studies on production of in situ TiB2-reinforced aluminum matrix functionally graded materials. At the same time, there is no study that the properties of composite, such as hardness and abrasive wear rate, are examined together according to centrifugal force. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-12-2019-0538/

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Segregation Effects and Phase Developments during Solidification of Alloy 625

Materials Science Forum ◽

10.4028/www.scientific.net/msf.508.373 ◽

2006 ◽

Vol 508 ◽

pp. 373-378 ◽

Cited By ~ 3

Author(s):

C. Højerslev ◽

Niels Tiedje ◽

J. Hald

Keyword(s):

Matrix Material ◽

Solute Concentration ◽

Chromium Concentration ◽

Laves Phase ◽

Pure Sample ◽

Alloy 625 ◽

Solidification Behaviour ◽

Planar Front ◽

Entire Matrix

The solidification behaviour of pure Alloy 625, and Alloy 625 enriched respectively in iron and carbon, was investigated in situ by hot-stage light optical microscopy. Using this technique planar front solidification for distances of several hundred microns was facilitated. After solidification, the material that experienced planar front solidification corresponded accurately to that of dendrites tens of microns in width adopting an equivalent dendrite arm width approach. Eventually, the planar solidification front broke down, where after the residual liquid solidified eutectic-like. This material contained γ-phase, Laves phase and, if carbon was dissolved in the liquid, niobium rich carbides formed. Molybdenum and niobium showed strong tendencies to segregate. Their segregation was balanced by inverse segregation of nickel and iron. The chromium concentration remained almost constant in γ in the entire matrix material. Addition of carbon did not cause detectable alterations of the material that experienced planar front solidification. However, it promoted the formation of niobium rich carbides in the material that solidified eutectic-like. Thus, this material differed from that of the pure sample in constitution, and consequently in γ-phase composition. Niobium rich carbides formed prior to Laves phase; in carbon rich volumes only the carbides form. As compared to the pure sample, the sample enriched in iron had decreased global minimal solute concentration in the material that experienced planar front solidification. However, once the concentrations were corrected with respect to the dilution simply caused by the presence of iron, the solidification behaviour in this material was identical to that of the pure sample. The constitution in the material that solidified eutectic-like was γ and Laves phase. As compared to the pure sample, the Laves phase was enriched in iron.

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In situ incorporation of a S, N doped carbon/sulfur composite for lithium sulfur batteries

RSC Advances ◽

10.1039/c5ra15360c ◽

2015 ◽

Vol 5 (95) ◽

pp. 78017-78025 ◽

Cited By ~ 38

Author(s):

Zhigao Yang ◽

Yu Dai ◽

Shengping Wang ◽

Hong Cheng ◽

Jingxian Yu

Keyword(s):

Carbon Material ◽

Matrix Material ◽

Carbon Precursor ◽

Lithium Sulfur Batteries ◽

The Matrix ◽

Co Doped ◽

Lithium Sulfur

A novel sulfur–nitrogen co-doped carbon material (SNC), which is obtained by taking polyaniline as the nitrogen-containing carbon precursor and then incorporating sulfur atomsin situas the matrix material for lithium sulfur batteries, is investigated.

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Si Nanopowder Based Anode Material for the Lithium Ion Battery Cell

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.822.230 ◽

2019 ◽

Vol 822 ◽

pp. 230-238

Author(s):

Aleksandr V. Morozov ◽

Aleksander Semencha ◽

Alexander B. Freidin ◽

Wolfgang H. Müller ◽

Margarita G. Dronova

Keyword(s):

Lithium Ion Battery ◽

Matrix Material ◽

Lithium Ion ◽

Point Of View ◽

Battery Cell ◽

Viscoelastic Matrix ◽

Technical Procedure ◽

The Matrix ◽

Spherically Symmetry

We consider a silicon nanopowder based anode for a lithium ion battery cell. We present the design of the battery cell ready for in situ Raman and X-ray experiments and a technical procedure for the cell manufacturing. From the continuum mechanics point of view, this type of anode can be represented by a spherical nanoparticle surrounded by viscoelastic matrix. During the charging process this nanoparticle undergoes a chemical reaction. Based on the chemical affinity concept we describe how the mechanical properties of the matrix material influence the kinetics of the charging process. We study spherically symmetry problems numerically for different sets of matrix material parameters and show their influence on the reaction front kinetics.

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In-situ visualisation of dynamic fracture and fragmentation of an L-type ordinary chondrite by combined synchrotron X-ray radiography and microtomography

Icarus ◽

10.1016/j.icarus.2021.114346 ◽

2021 ◽

Vol 359 ◽

pp. 114346

Author(s):

Lukasz Farbaniec ◽

David J. Chapman ◽

Jack R.W. Patten ◽

Liam C. Smith ◽

James D. Hogan ◽

...

Keyword(s):

Dynamic Fracture ◽

Ordinary Chondrite ◽

X Ray

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Microstructure and Mechanical Properties of TiB2/Al Composites

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.399-401.2266 ◽

2011 ◽

Vol 399-401 ◽

pp. 2266-2270 ◽

Cited By ~ 1

Author(s):

Shuai Chen ◽

Yu Tao Zhao ◽

Hua Jin

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Phase Composition ◽

Ultimate Tensile Strength ◽

Master Alloy ◽

Volume Fraction ◽

Matrix Material ◽

The Matrix ◽

Ti Powder

Abstract:TiB2/Al composites were prepared by the melt in situ reaction fabrication using Al-3B master alloy and Ti powder as the reactive materials. The phase composition and the microstructure of the as-prepared composites were investigated by XRD, SEM. The results indicate that the reinforcements are TiB2 and a small amount of Al3Ti. TiB2particles are in the shape of irregular polygon or rectangle, and its size is 0.5-2μm. Compared with the matrix material, the ultimate tensile strength, microhardness of as-prapred composites increase by 51%, 68.8%, 85.2%, and 33.4%, 43.8%, 55%, respectively. However, the elongation decrease with the volume fraction of the reinforcements increased.

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A Polymer for Application as a Matrix Phase in a Concept of In Situ Curable Bioresorbable Bioactive Load-Bearing Continuous Fiber Reinforced Composite Fracture Fixation Plates

Molecules ◽

10.3390/molecules26051256 ◽

2021 ◽

Vol 26 (5) ◽

pp. 1256

Author(s):

Artem Plyusnin ◽

Jingwei He ◽

Cindy Elschner ◽

Miho Nakamura ◽

Julia Kulkova ◽

...

Keyword(s):

Mechanical Properties ◽

Fracture Fixation ◽

Matrix Material ◽

Matrix Phase ◽

Morphological Development ◽

The Novel ◽

Load Bearing ◽

The Matrix ◽

Novel Concept

The use of bioresorbable fracture fixation plates made of aliphatic polyesters have good potential due to good biocompatibility, reduced risk of stress-shielding, and eliminated need for plate removal. However, polyesters are ductile, and their handling properties are limited. We suggested an alternative, PLAMA (PolyLActide functionalized with diMethAcrylate), for the use as the matrix phase for the novel concept of the in situ curable bioresorbable load-bearing composite plate to reduce the limitations of conventional polyesters. The purpose was to obtain a preliminary understanding of the chemical and physical properties and the biological safety of PLAMA from the prospective of the novel concept. Modifications with different molecular masses (PLAMA-500 and PLAMA-1000) were synthesized. The efficiency of curing was assessed by the degree of convergence (DC). The mechanical properties were obtained by tensile test and thermomechanical analysis. The bioresorbability was investigated by immersion in simulated body fluid. The biocompatibility was studied in cell morphology and viability tests. PLAMA-500 showed better DC and mechanical properties, and slower bioresorbability than PLAMA-1000. Both did not prevent proliferation and normal morphological development of cells. We concluded that PLAMA-500 has potential for the use as the matrix material for bioresorbable load-bearing composite fracture fixation plates.

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A Compact Gas-Cooled Fast Reactor with an Ultra-Long Fuel Cycle

Science and Technology of Nuclear Installations ◽

10.1155/2013/618707 ◽

2013 ◽

Vol 2013 ◽

pp. 1-10 ◽

Cited By ~ 5

Author(s):

Hangbok Choi ◽

Robert W. Schleicher ◽

Puja Gupta

Keyword(s):

Fast Reactor ◽

Nuclear Power ◽

Fuel Cycle ◽

Matrix Material ◽

Reactor Core ◽

Operation Time ◽

Fuel Load ◽

Fissile Material ◽

Reactor Physics

In an attempt to allow nuclear power to reach its full economic potential, General Atomics is developing the Energy Multiplier Module (EM2), which is a compact gas-cooled fast reactor (GFR). The EM2augments its fissile fuel load with fertile materials to enhance an ultra-long fuel cycle based on a “convert-and-burn” core design which converts fertile material to fissile fuel and burns it in situ over a 30-year core life without fuel supplementation or shuffling. A series of reactor physics trade studies were conducted and a baseline core was developed under the specific physics design requirements of the long-life small reactor. The EM2core performance was assessed for operation time, fuel burnup, excess reactivity, peak power density, uranium utilization, etc., and it was confirmed that an ultra-long fuel cycle core is feasible if the conversion is enough to produce fissile material and maintain criticality, the amount of matrix material is minimized not to soften the neutron spectrum, and the reactor core size is optimized to minimize the neutron loss. This study has shown the feasibility, from the reactor physics standpoint, of a compact GFR that can meet the objectives of ultra-long fuel cycle, factory-fabrication, and excellent fuel utilization.

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