Influence of incoherent nanosized particles on the annihilation of dislocations in heterophase aluminum-matrix crystalline alloys

2021 ◽  
Vol 64 (10) ◽  
pp. 98-103
Author(s):  
O.I. Daneyko ◽  
◽  
et al.
Keyword(s):  
Aluminum Matrix ◽  
Nanosized Particles

The use of charging effects in Al/Al2O3 metal matrix composite materials as contrast mechanism in the SEM

1990 ◽  
Vol 48 (4) ◽  
pp. 422-423
Author(s):  
Andreas M. Borchert
Keyword(s):  
Secondary Electron ◽  
Aluminum Matrix ◽  
Interfacial Structure ◽  
Resolving Power ◽  
Coated Sample ◽  
Material Combination ◽  
Uncoated Sample ◽  
Backscattered Electrons ◽  
Contrast Mechanism ◽  
Good Contrast

In Al/Al2O3 MMC's the metal/ceramic interfacial structure is of great concern because aluminum does not wet (i.e. bond) well to alumina. One proposed method to overcome this problem is to form a magnesium-rich spinel (MgAl2O4) as an additional phase between the aluminum matrix and the alumina particle. The spinel forms by diffusion of Mg from the matrix and improves the bonding. Typically the SEM would be the most suitable instrument to study the spinel, but this particular material combination (alumina/spinel) does not have sufficient secondary or backscattered electron contrast to allow for normal imaging. The purpose of this work was to develop a technique for examining the growth and morphology of this spinel at the Al/Al2O3 interface. Samples of an Al/Al2O3 MMC with a spinel at the particle interface were prepared according to standard metallographic procedures. Certain samples were sputter coated with a gold film of approximately 12 nm thickness; other samples were examined uncoated. Nonconductive, uncoated specimens charge under the incident electron beam if the accelerating voltage is below E1 or above E2 in Figure 1. In both of cases (below E1 and above E2) the number of electrons entering the sample is higher than the number of electrons leaving the sample. The resolving power of the SEM is usually degraded by this effect and therefore nonconductive specimens are coated with a layer of conductive material prior to observation. Figure 2 shows how this effect can create contrast between two materials due to its effect on the secondary electron detector bias voltage. Figure 3 shows that this contrast mechanism exists for the material combination alumina/spinel. The secondary electron image of a coated sample (3a) shows almost no contrast between alumina and spinel whereas the uncoated sample (3b) shows good contrast due to the different charging characteristics of the materials. The alumina charges stronger than the spinel and appears brighter in the image. The assumption that the effect is due to secondary electrons is supported by Figure 4. The micrograph in Figure 4a was obtained by backscattered electrons only and shows poor contrast whereas the micrograph in Figure 4b was obtained by secondary and backscattered electrons and shows good contrast. Figure 5 shows micrographs obtained at different operating voltages. The reduction in contrast at lower operating voltages is due to reduced charging.

Using explosive energy for processing aluminum matrix composites

2000 ◽  
Vol 10 (PR9) ◽  
pp. Pr9-119-Pr9-122
Author(s):  
V. Popov ◽  
V. Gulbin ◽  
E. Sungurov
Keyword(s):  
Aluminum Matrix ◽  
Aluminum Matrix Composites ◽  
Matrix Composites ◽  
Explosive Energy

Effect of Titanium Carbide Particles on Mechanical Properties of Aluminum Matrix Composites

2017 ◽  
Vol 5 (2) ◽  
pp. 20-30
Author(s):  
Zaman Khalil Ibrahim
Keyword(s):  
Mechanical Properties ◽  
Titanium Carbide ◽  
Compression Strength ◽  
Volume Fraction ◽  
Aluminum Matrix ◽  
Aluminum Matrix Composites ◽  
Matrix Composites ◽  
Powder Metallurgy Technique ◽  
Carbide Particles ◽  
Properties Of Composites

In this research aluminum matrix composites (AMCs) was reinforced by titanium carbide (TiC) particles and was produced. Powder metallurgy technique (PM) has been used to fabricate AMCs reinforced with various amounts (0%, 4%, 8%, 12%, 16% and 20% volume fraction) of TiC particles to study the effect of different volume fractions on mechanical properties of the Al-TiC composites. Measurements of compression strength and hardness showed that mechanical properties of composites increased with an increase in volume fraction of TiC Particles. Al-20 % vol. TiC composites exhibited the best properties with hardness value (97HRB) and compression strength value (275Mpa).

Macro-Micro Relationship of Dimensional Changing Behavior of Aluminum Matrix Composite

2020 ◽  
Author(s):  
Deng Gong ◽  
Longtao Jiang ◽  
Youfang Cao ◽  
Yuanzi Zhou ◽  
Tingting Guo ◽  
...  
Keyword(s):  
Matrix Composite ◽  
Aluminum Matrix ◽  
Aluminum Matrix Composite ◽  
Relationship Of

Review on Methodologies Used in the Synthesis of Metal Nanoparticles: Significance of Phytosynthesis Using Plant Extract as an Emerging Tool

2020 ◽  
Vol 26 (40) ◽  
pp. 5188-5204
Author(s):  
Uzair Nagra ◽  
Maryam Shabbir ◽  
Muhammad Zaman ◽  
Asif Mahmood ◽  
Kashif Barkat
Keyword(s):  
Green Synthesis ◽  
Metal Nanoparticles ◽  
Plant Extracts ◽  
Biomedical Applications ◽  
Noble Metals ◽  
Cost Effective ◽  
Green Technology ◽  
Critical Parameters ◽  
Nanosized Particles ◽  
Preparation Methods

Nanosized particles, with a size of less than 100 nm, have a wide variety of applications in various fields of nanotechnology and biotechnology, especially in the pharmaceutical industry. Metal nanoparticles [MNPs] have been synthesized by different chemical and physical procedures. Still, the biological approach or green synthesis [phytosynthesis] is considered as a preferred method due to eco-friendliness, nontoxicity, and cost-effective production. Various plants and plant extracts have been used for the green synthesis of MNPs, including biofabrication of noble metals, metal oxides, and bimetallic combinations. Biomolecules and metabolites present in plant extracts cause the reduction of metal ions into nanosized particles by one-step preparation methods. MNPs have remarkable attractiveness in biomedical applications for their use as potential antioxidant, anticancer and antibacterial agents. The present review offers a comprehensive aspect of MNPs production via top-to-bottom and bottom-to-top approach with considerable emphasis on green technology and their possible biomedical applications. The critical parameters governing the MNPs formation by plant-based synthesis are also highlighted in this review.

Composite cladded powders for spraying of protective coatings

2019 ◽  
pp. 59-64
Author(s):  
E. Yu. Gerashchenkova ◽  
T. I. Bobkova ◽  
E. A. Samodelkin ◽  
B. V. Farmakovsky
Keyword(s):  
Tungsten Carbide ◽  
Gas Phase ◽  
High Speed ◽  
Protective Coatings ◽  
Powder Materials ◽  
Nanosized Particles

The paper presents results of the development of technology for producing cladded and surfacealloyed powder materials. High-speed mechanosynthesis of matrix powders of FeCrAl and solid nanosized particles of tungsten carbide occurs in a disintegrator in the presence of an active gas phase (nitrogen).

Nanocarbon in the Structure of a Hypereutectic Aluminum-Matrix Composite

2020 ◽  
Vol 14 (4) ◽  
pp. 668-672 ◽  
Author(s):  
A. S. Aronin ◽  
I. M. Aristova ◽  
G. E. Abrosimova ◽  
V. V. Vasenev ◽  
V. N. Mironenko
Keyword(s):  
Matrix Composite ◽  
Aluminum Matrix ◽  
Aluminum Matrix Composite
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