Volume Distribution of Reinforce Particles in a Metal Matrix

2020 ◽  
Vol 992 ◽  
pp. 421-426
Author(s):  
A.A. Fedotov ◽  
M.N. Safonova ◽  
A.S. Syromiatnikova
Keyword(s):  
Metal Matrix ◽  
Natural Diamond ◽  
The Body ◽  
Volume Distribution ◽  
Hardening Mechanism ◽  
The Matrix ◽  
Insurmountable Obstacle ◽  
Diamond Powders ◽  
Positive Effect ◽  
Metal Basis

The authors studied the volume distribution of particles from ultrafine powders of natural diamond, used as a hardener for a post of diamond tools made on a metal basis by powder metallurgy methods. In [15-17], the authors determined that the addition of ultrafine natural diamond powders to the melt of tin bronze in an amount of 2-3% by weight has a positive effect on the physicomechanical and operational properties of the metal post. It was also determined that the hardening mechanism of the materials under study depends on the nature of the distribution of the hardener particles in the bulk of the matrix. In accordance with previous studies, the authors set the aim - to determine the distribution nature of reinforcing phase particles in the volume of the metal matrix. The studies were carried out using optical metallography, SEM microscopy and Raman spectroscopy. It was established that the particles of the hardener in the volume of the matrix are distributed evenly along the phase boundaries and in the body of the grains and reduce the number of pores formed during sintering compared with the original samples. With the established nature of the distribution of particles, a grain-boundary hardening mechanism is realized, in which dislocations are inhibited by grain boundaries, which are an insurmountable obstacle for them. It is also established that a part of the particles settle directly inside the grains of the material and is distributed throughout the volume uniformly contributing to the dispersion hardening mechanism.

The metal matrix composite containing natural diamond powders of different dispersity

2015 ◽  
Author(s):  
A. S. Syromyatnikova ◽  
M. N. Safonova ◽  
V. A. Kim ◽  
P. P. Tarasov ◽  
A. A. Fedotov
Keyword(s):  
Metal Matrix Composite ◽  
Matrix Composite ◽  
Metal Matrix ◽  
Natural Diamond ◽  
Diamond Powders

Effect of graphene nano-platelets on mechanical and impact characteristics of carbon/Kevlar reinforced epoxy hybrid nanocomposites

2021 ◽  
pp. 095440622110168
Author(s):  
Mohamad Alsaadi ◽  
Bashar Younus ◽  
Ahmet Erklig ◽  
Mehmet Bulut ◽  
Omer Bozkurt ◽  
...  
Keyword(s):  
Impact Test ◽  
Charpy Impact ◽  
Hybrid Nanocomposites ◽  
Matrix Composites ◽  
Sem Images ◽  
The Matrix ◽  
Impact Characteristics ◽  
Positive Effect ◽  
Hybrid Carbon ◽  
Composite Samples

The influence of various graphene nano-platelets (GNPs) content on the tensile, flexural and Charpy impact characteristics of carbon, Kevlar and hybrid carbon/Kevlar fibers reinforced epoxy matrix composites was investigated. Both of composite configurations as carbon and Kevlar at outer and core skins were experimentally tested. The SEM images for flexural specimens were taken to observe the adhesion mechanism of GnPs particles with fiber/epoxy system. It is found that hybridization with Kevlar layers is contributed a positive effect on the hybrid carbon/Kevlar laminate structures in terms of tensile, flexural and impact behaviour. The incorporation of GnPs particles in hybrid and non-hybrid composite samples results in significant improvements in tensile, flexural and impact properties, and the greatest improvement occurs within the GnPs particle content of 0.1 and 0.25 wt%, indicating that the interfacial bonding between the matrix and the fibers is better due to the large surface area of the GnPs and the good entanglement between the GnPs layers and the matrix chains. The samples of impact test are experimented for edgewise and flatwise directions.

scholarly journals Fabrication and Characterization of the Modified EV31-Based Metal Matrix Nanocomposites

Metals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 125
Author(s):  
Seyed Kiomars Moheimani ◽  
Mehran Dadkhah ◽  
Mohammad Hossein Mosallanejad ◽  
Abdollah Saboori
Keyword(s):  
Thermal Expansion ◽  
Mechanical Strength ◽  
Metal Matrix ◽  
Coefficient Of Thermal Expansion ◽  
Structural Effect ◽  
Metal Matrix Nanocomposites ◽  
Mechanical Stirring ◽  
Specific Strength ◽  
The Matrix ◽  
Matrix Nanocomposites

Metal matrix nanocomposites (MMNCs) with high specific strength have been of interest for numerous researchers. In the current study, Mg matrix nanocomposites reinforced with AlN nanoparticles were produced using the mechanical stirring-assisted casting method. Microstructure, hardness, physical, thermal and electrical properties of the produced composites were characterized in this work. According to the microstructural evaluations, the ceramic nanoparticles were uniformly dispersed within the matrix by applying a mechanical stirring. At higher AlN contents, however, some agglomerates were observed as a consequence of a particle-pushing mechanism during the solidification. Microhardness results showed a slight improvement in the mechanical strength of the nanocomposites following the addition of AlN nanoparticles. Interestingly, nanocomposite samples were featured with higher electrical and thermal conductivities, which can be attributed to the structural effect of nanoparticles within the matrix. Moreover, thermal expansion analysis of the nanocomposites indicated that the presence of nanoparticles lowered the Coefficient of Thermal Expansion (CTE) in the case of nanocomposites. All in all, this combination of properties, including high mechanical strength, thermal and electrical conductivity, together with low CTE, make these new nanocomposites very promising materials for electro packaging applications.

scholarly journals The Dimension of the Body in Higher Education: Matrix of Meanings in Students’ Diaries

Human Arenas ◽  
2021 ◽  
Author(s):  
Ramiro Tau ◽  
Laure Kloetzer ◽  
Simon Henein
Keyword(s):  
Higher Education ◽  
Performing Arts ◽  
Teaching And Learning ◽  
Educational Practice ◽  
The Body ◽  
Cultural Perspective ◽  
General Process ◽  
Emotional Dimension ◽  
The Matrix ◽  
The Mind

AbstractIn this paper, we attempt to show some consequences of bringing the body back into higher education, through the use of performing arts in the curricular context of scientific programs. We start by arguing that dominant traditions in higher education reproduced the mind-body dualism that shaped the social matrix of meanings on knowledge transmission. We highlight the limits of the modern disembodied and decontextualized reason and suggest that, considering the students’ and teachers’ bodies as non-relevant aspects, or even obstacles, leads to the invisibilization of fundamental aspects involved in teaching and learning processes. We thus conducted a study, from a socio-cultural perspective, in which we analyse the emerging matrix of meanings given to the body and bodily engagement by students, through a systematic qualitative analysis of 47 personal diaries. We structured the results and the discussion around five interpretative axes: (1) the production of diaries enables historicization, while the richness of bodily experience expands the boundaries of diaries into non-textual modalities; (2) curricular context modulates the emergent meanings of the body; (3) physical and symbolic spaces guide the matrix of bodily meanings; (4) the bodily dimension of the courses facilitates the emergence of an emotional dimension to get in touch with others and to register one's own emotional experiences; and (5) the body functions as a condition for biographical continuity. These axes are discussed under the light of the general process of consciousness-raising and resignification of the situated body in the educational practice.

A study on the microstructure, hardness, and tribological behavior of aluminum-based metal–matrix composite fabricated through recursive friction stir processing

2020 ◽  
pp. 146442072097668
Author(s):  
G Girish ◽  
V Anandakrishnan
Keyword(s):  
Metal Matrix Composite ◽  
Matrix Composite ◽  
Friction Stir Processing ◽  
Metal Matrix ◽  
Applied Load ◽  
Tribological Behavior ◽  
Testing Conditions ◽  
Friction Stir ◽  
The Matrix ◽  
Microstructure Examination

In this work, an Al–Zn–Mg–Cu/TiC metal–matrix composite was fabricated through recursive friction stir processing, and its microstructure, hardness, and tribological properties were investigated. Microstructure examination revealed a homogeneous dispersion of TiC particles in the matrix after six recursive passes. The grains were significantly refined and microhardness of the composite improved due to the presence of TiC particles. Friction coefficient and wear rate of the composite went up with an increase in the applied load and dropped significantly at higher sliding velocities. The morphology of the wear specimens experimented under different testing conditions was analyzed and the corresponding wear mechanisms discussed.

scholarly journals Predictive Computational Model for Damage Behavior of Metal-Matrix Composites Emphasizing the Effect of Particle Size and Volume Fraction

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2143
Author(s):  
Shaimaa I. Gad ◽  
Mohamed A. Attia ◽  
Mohamed A. Hassan ◽  
Ahmed G. El-Shafei
Keyword(s):  
Finite Element ◽  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Volume Fraction ◽  
Particulate Composites ◽  
Aluminum Matrix Composites ◽  
Matrix Composites ◽  
Zone Method ◽  
Stress Strain ◽  
The Matrix

In this paper, an integrated numerical model is proposed to investigate the effects of particulate size and volume fraction on the deformation, damage, and failure behaviors of particulate-reinforced metal matrix composites (PRMMCs). In the framework of a random microstructure-based finite element modelling, the plastic deformation and ductile cracking of the matrix are, respectively, modelled using Johnson–Cook constitutive relation and Johnson–Cook ductile fracture model. The matrix-particle interface decohesion is simulated by employing the surface-based-cohesive zone method, while the particulate fracture is manipulated by the elastic–brittle cracking model, in which the damage evolution criterion depends on the fracture energy cracking criterion. A 2D nonlinear finite element model was developed using ABAQUS/Explicit commercial program for modelling and analyzing damage mechanisms of silicon carbide reinforced aluminum matrix composites. The predicted results have shown a good agreement with the experimental data in the forms of true stress–strain curves and failure shape. Unlike the existing models, the influence of the volume fraction and size of SiC particles on the deformation, damage mechanism, failure consequences, and stress–strain curve of A359/SiC particulate composites is investigated accounting for the different possible modes of failure simultaneously.

scholarly journals Interfacial Aspects of Metal Matrix Composites Prepared from Liquid Metals and Aqueous Solutions: A Review

Metals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1400
Author(s):  
Peter Baumli
Keyword(s):  
Aqueous Solutions ◽  
Physical Properties ◽  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Liquid Metals ◽  
Interfacial Phenomena ◽  
Matrix Composites ◽  
Good Adhesion ◽  
Mechanical And Physical Properties ◽  
The Matrix

The paper reviews the preparation of the different metallic nanocomposites. In the preparation of composites, especially in the case of nanocomposites, interfacial phenomena play an important role. This review summarizes the literature on various interfacial phenomena, such as wettability and reactivity in the case of casting techniques and colloidal behavior in the case of electrochemical and electroless methods. The main contribution of this work lies in the evaluation of collected interfacial phenomena and difficulties in the production of metal matrix composites, for both nano-sized and micro-sized reinforcements. This study can guide the composite maker in choosing the best criteria for producing metal matrix composites, which means a real interface with good adhesion between the matrix and the reinforcement. This criterion results in desirable mechanical and physical properties and homogenous dispersion of the reinforcement in the matrix.

scholarly journals The nutritional use of millet grain for food and feed: a review

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Z. M. Hassan ◽  
N. A. Sebola ◽  
M. Mabelebele
Keyword(s):  
Phenolic Compounds ◽  
Human Health ◽  
Pearl Millet ◽  
Egg Production ◽  
Positive Impact ◽  
The Body ◽  
Broiler Performance ◽  
Food And Feed ◽  
High Antioxidant Activity ◽  
Positive Effect

AbstractWorldwide, millets are regarded as a significant grain, however, they are the least exploited. Millet grain is abundant in nutrients and health-beneficial phenolic compounds, making it suitable as food and feed. The diverse content of nutrients and phenolic compounds present in finger and pearl millet are good indicators that the variety of millet available is important when selecting it for use as food or feed. The phenolic properties found in millets compromise phenolic acids, flavonoids, and tannins, which are beneficial to human health. Moreover, finger millet has an exceptionally unique, more abundant, and diverse phenolic profile compared to pearl millet. Research has shown that millet phenolic properties have high antioxidant activity. The presence of phytochemicals in millet grains has positive effect on human health by lowering the cholesterol and phytates in the body. The frantic demands on maize and its uses in multiple industries have merited the search for alternative grains, to ease the pressure. Substitution of maize with pearl and finger millets in the diets of different animals resulted in positive impact on the performance. Including these grains in the diet may improve health and decrease the risks of diseases. Pearl millet of 50% or more can be used in broiler diets without adversely affecting broiler performance or egg production. Of late, millet grain has been incorporated in other foods and used to make traditional beverages. Thus, the core aim of this review is to provide insight and comprehension about the nutritional and phenolic status of millets and their impact on human and livestock.

Small angle reconstruction of plasma luminosity for spherical tokamak

2020 ◽  
Author(s):  
А.Н. Баженов ◽  
П.А. Затылкин
Keyword(s):  
Power Plants ◽  
Essential Feature ◽  
Real Data ◽  
The Body ◽  
Magnetic Sensors ◽  
Test Problems ◽  
General View ◽  
Central Projection ◽  
The Matrix ◽  
Matrix Detector

Публикация посвящена применению методов вычислительной геометрии, интервального анализа и линейного программирования к задачам физики управляемого термоядерного синтеза. Рассмотрены геометрические аспекты проблемы, получены проекции светимостей различных объемов сферического токамака на плоскость матричного детектора, изучены изображения предполагаемых макроскопических структур и микроскопических включений. Для набора модельных распределений светимости объема токамака поставлена задача восстановления сигнала. Решение получено с использованием задач линейного программирования. The problems of reconstruction of plasma luminosity are important for physics and technology of power plants-tokamaks. The Globus-M research tokamak obtained a large amount of data using a matrix detector in pinhole camera geometry. From the mathematical point of view, finding the luminosity for different regions of the plasma volume according to the matrix detector is an inverse problem related to the field of integral geometry. An essential feature of the particular task is the use of a single fixed camera with a small viewing angle. In this regard, application of methods of harmonic analysis of data is not enough. The paper investigates the geometric aspects of the problem. In the general view, a threedimensional object is projected onto a two-dimensional plane through a diaphragm. Under the assumption of azimuthal symmetry, there is a central projection of the luminosity of the body of rotation onto a flat matrix detector. The initial information for the calculation is the plasma boundary obtained from magnetic sensors. There is no reliable information about the internal structure of the plasma, so its division into regions of the equal luminosity is not unambiguous. The paper presents an algorithm for finding the projections of the luminosity of plasma volumes on the plane of the matrix detector. A set of model direct problems for the construction of algorithms for their recognition according to the detector data was investigated. Images of supposed macroscopic structures and microscopic inclusions were obtained. The methodological basis of the work is the use of interval analysis methods for solving geometric and algebraic problems. This approach allows obtaining qualitative and quantitative results that takes into account the uncertainty of the input data with the minimum amount of computational costs. Algebraic solvability is investigated in the interval formulation using response functionality. Solutions for a set of test problems are obtained, which demonstrate the availability of successful reconstruction for real data. An important result of the study is an information about the presence of uncertainties in geometric data and related calculations by obtaining results about the luminosity of the plasma by solving linear programming problems.

Research of the process of synthesis and properties of the obtained metal-matrix composite powders of the Ti/tib2 system

2021 ◽  
pp. 66-73
Author(s):  
M. E. Goshkoderya ◽  
T. I. Bobkova ◽  
M. V. Staritsyn
Keyword(s):  
Metal Matrix Composite ◽  
Matrix Composite ◽  
Metal Matrix ◽  
Composite Powders ◽  
Optimal Ratio ◽  
The Matrix ◽  
Series Of Experiments ◽  
Sprayed Coatings

The paper proposes a method for preparing composite powders of the Ti/TiB2 system, studies the properties of the obtained composite powders, and also shows a series of experiments on its microplasma spraying. The properties of the sprayed coatings were investigated. On its basis the optimal ratio of the matrix and reinforcing components was established in order to increase significantly the hardness of the sprayed coatings.

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