Processing and Manufacturing of Metal Matrix Aluminum Alloys Composites Reinforced by Silicon Carbide and Alumina through Powder Metallurgy Techniques

2012 ◽  
Vol 727-728 ◽  
pp. 254-258
Author(s):  
Everthon Rodrigues de Araujo ◽  
Sérvulo José Ferreira Alves ◽  
Francisco Ambrozio Filho ◽  
Severino Leopoldino Urtiga Filho ◽  
Oscar Olimpio de Araújo Filho
Keyword(s):  
Metal Matrix ◽  
The Other ◽  
Particulate Phase ◽  
Vacuum Sintering ◽  
Hardness Tests ◽  
The Matrix ◽  
Conventional Material ◽  
Uniaxial Compaction ◽  
Matrix Aluminum Alloys ◽  
Sintered Materials

Composites are combinations of two materials in which one of the materials, called the reinforcing phase, is in the form of fibers, sheets, or particles and is embedded in the other materials called the matrix phase. If the composite is designed and fabricated correctly, it combines the strength of the reinforcement with the toughness of the matrix to achieve a combination of desirable properties not available in any single conventional material. In this work of research aluminium alloy AA6061 was reinforced by 5, 10 and 15% (in mass %) of SiC and Al2O3 by mechanical alloying in a vibratory type SPEX mill, cold uniaxial compaction and vacuum sintering in order to investigate the influence of the particulate phase in the microstructure and mechanical properties of the composites obtained. The microstructure of the powders and the sintered materials were evaluated by SEM and the hardness was evaluated by hardness tests.

Preparation of Metal Matrix Aluminum Alloys Composites Reinforced by Silicon Nitride and Aluminum Nitride through Powder Metallurgy Techniques

2012 ◽  
Vol 727-728 ◽  
pp. 259-262 ◽  
Author(s):  
Everthon Rodrigues de Araujo ◽  
Marcio Marcelo Sampaio de Souza ◽  
Francisco Ambrozio Filho ◽  
Cezar Henrique Gonzalez ◽  
Oscar Olimpio de Araújo Filho
Keyword(s):  
Silicon Nitride ◽  
Metal Matrix ◽  
Low Cost ◽  
Matrix Material ◽  
Hardness Test ◽  
Matrix Composites ◽  
Mechanical And Physical Properties ◽  
Uniaxial Compaction ◽  
Matrix Aluminum Alloys ◽  
Sintered Materials

The aliminium alloys are of particular interest to both the aerospace industry and automotive industry because of their attractive combinations of properties such as medium strength, formability, weldability, corrosion resistance and low cost. Compared with a metal matrix material, significant improvements in the mechanical and physical properties such as strength, toughness, and thermal conductivity can be achievied in metal matrix composites (MMCs). In this work of investigation aluminium alloy AA6061 was reinforced by 5, 10 and 15% (in mass %) of Si3N4 (silicon nitride) and AlN (aluminium nitride) by mechanical alloying in a vibratory type SPEX mill, cold uniaxial compaction and vacuum sitering in order to investigate the influence of the particulate phase in the microstructure and mechanical properties of the composites obtained. The microstructure of the powders and the sintered materials were evaluated by means of SEM and the hardness and were evaluated by hardness test.

Reinforcement of 2124 Al Alloy with Low Micron SiC and Nano Al2O3 via Solid-State Forming

2015 ◽  
Vol 828-829 ◽  
pp. 172-178
Author(s):  
Zizo Gxowa ◽  
Sigqibo Templeton Camagu ◽  
Gonasagren Govender ◽  
Manuel Filipe Pereira
Keyword(s):  
Grain Boundaries ◽  
Metal Matrix ◽  
Volume Fraction ◽  
Al Alloy ◽  
Matrix Composites ◽  
Intergranular Cracking ◽  
Powder Metallurgical Process ◽  
Hardness Tests ◽  
Mode Of Failure ◽  
The Matrix

A powder metallurgical process was used to fabricate Metal Matrix Composites (MMCs). A 2124 aluminium alloy was reinforced with 5 and 10 vol.% of Al2O3(40-70nm) to form Metal Matrix Nano Composites (MMNCs) as well as 10 and 15 vol.% of SiC (1-10µm) to fabricate low micron MMCs. It was observed that the nano-sized Al2O3particles were evenly dispersed in the aluminium matrix while a lot of loose SiC particles settled on the grain boundaries in the low micron MMCs. The relative density of all the composites increased due to sintering, however full densification was not achieved. This result was attributed to the hindered motion of dislocations, grains and grain boundaries by reinforcing particles. The 2124-Al/10%-SiC composite was cold extruded and the extruded part fractured. A metallographic evaluation was carried out and it was deduced that the mode of failure was intergranular cracking. Hardness tests performed after sintering indicated that hardness increased with an increase in volume fraction of reinforcement in the matrix. Annealing of the extruded part resulted in a decrease in hardness.

The Effects of Homogenization Time and Cooling Environment on Microstructure and Transformation Temperatures of Ni-42.5wt%Ti-7.5wt%Cu Alloy

2010 ◽  
Vol 297-301 ◽  
pp. 344-350 ◽  
Author(s):  
E. Omrani ◽  
Ali Shokuhfar ◽  
A. Etaati ◽  
A. Dorri M. ◽  
A. Saatian
Keyword(s):  
Cooling Rate ◽  
The Other ◽  
Vacuum Arc ◽  
Electron Microscopic ◽  
Transformation Temperatures ◽  
Cu Alloy ◽  
Arc Melting ◽  
Homogenization Time ◽  
Hardness Tests ◽  
The Matrix

The present paper deals with different effects of homogenization time and cooling environment on Ni-42.5wt%Ti-7.5wt%Cu alloy. The alloy was prepared by vacuum arc melting. Afterwards, three homogenization times (half, one and two hour) and three cooling environments (water, air and furnace) at 1373 K were selected. Optical and Scanning Electron Microscopic methods, EDX, DSC and hardness tests have been used to evaluate the microstructure, transformation temperatures and hardness. Results indicate that specimens that were cooled in air are super-saturated. Also, the microstructure from furnace cooling has many disparities with the other cooling environments’ microstructure and two types of precipitates exhibit in the matrix, but in other cooling environments, only one phase can be seen. Particles of the Ti2(Ni,Cu) phase are distributed in the matrix in all of the microstructures irrespective of cooling rate. Observations show that increasing the time of homogenization results in finer precipitates and uniform distribution in the matrix. In addition, alteration of cooling rate and time of homogenization affect the martensitic transformation temperatures. On the other hand, the hardness varies slightly for different homogenization times but declines extremely with decreasing cooling rate. Moreover homogenization time and the cooling environment affect the transformation temperatures on furnace cooled samples.

Effects of waste eggshells and SiC addition in the synthesis of aluminum hybrid green metal matrix composite

2017 ◽  
Vol 6 (1) ◽  
Author(s):  
Shashi Prakash Dwivedi ◽  
Satpal Sharma ◽  
Raghvendra Kumar Mishra
Keyword(s):  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Weight Ratio ◽  
Matrix Alloy ◽  
The Other ◽  
Matrix Composites ◽  
Transmission Electron ◽  
Aa2014 Alloy ◽  
The Matrix ◽  
Electron Microscope Image

AbstractThe mechanical behavior, physical behavior, microstructural characteristics, and corrosion behavior of AA2014/silicon carbide (SiC)/carbonized eggshell hybrid green metal matrix composites (MMCs) were investigated. Twenty-five samples of hybrid composite with different combinations of SiC and carbonized eggshell particles in AA2014 matrix alloy were prepared. Microstructure presents that the reinforcement particles (SiC and eggshells) are uniformly distributed in the matrix AA2014 alloy. Transmission electron microscope image shows proper wettability between SiC, carbonized eggshell, and AA2014 aluminum alloy. The tensile strength and the fatigue strength for the composites containing 2.5 wt.% SiC up to 7.5 wt.% carbonized eggshell were observed to be higher than that of the other selected composites. The hardness values for the composites containing 12.5 wt.% SiC and 2.5 wt.% carbonized eggshell were in all cases higher than that of the other composites. The results show that toughness decreases with the increase in the weight ratio of SiC and carbonized eggshell in the composites. The results reveal that the sample of AA2014/2.5% SiC/12.5% carbonized eggshell shows minimum corrosion rate among all the selected samples. Density, porosity, and overall cost of hybrid metal matrix composites were also calculated to see the effects of carbonized eggshell and SiC addition in AA2014 matrix alloy.

Development of Aluminium Alloys and Metal Matrix Composites by Powder Metallurgy

2007 ◽  
Vol 23 ◽  
pp. 51-58 ◽  
Author(s):  
E.M. Ruiz-Navas ◽  
M.L. Delgado ◽  
José M. Torralba
Keyword(s):  
Metal Matrix Composites ◽  
Oxide Layer ◽  
Aluminium Alloys ◽  
Metal Matrix ◽  
The Other ◽  
Matrix Composites ◽  
Aluminium Matrix Composite ◽  
The Matrix ◽  
Aluminium Metal ◽  
Layer Problem

Consolidation of aluminium alloys by sintering present a main problem: the oxide layer that cover aluminium particles. Some alternatives are studied in this work as solution to the oxide layer problem during the sintering of series 2xxx aluminium alloys. One of these solutions is related to the addition of tin traces, and the other is the addition of a second alloy. Moreover, aluminium metal matrix composites are characterized by excellent properties as combination of properties which comes from the matrix and from the reinforcement. In the first part of this work is analyzed the influence of trace additions, and the last part of this study is focused to the analysis of one aluminium matrix composite as the influence of several quantities of reinforcement.

Pembobotan Berdasarkan Tingkat Kesamaan Semantik pada Metode Fuzzy Semi-Supervised Co-Clustering untuk Pengelompokkan Dokumen Teks

2014 ◽  
Vol 6 (2) ◽  
pp. 46-51
Author(s):  
Galang Amanda Dwi P. ◽  
Gregorius Edwadr ◽  
Agus Zainal Arifin
Keyword(s):  
Supervised Learning ◽  
Semantic Similarity ◽  
The Other ◽  
Classification Result ◽  
Document Similarity ◽  
The Matrix ◽  
Index Terms ◽  
Membership Value ◽  
Degree Of Similarity

Nowadays, a large number of information can not be reached by the reader because of the misclassification of text-based documents. The misclassified data can also make the readers obtain the wrong information. The method which is proposed by this paper is aiming to classify the documents into the correct group.  Each document will have a membership value in several different classes. The method will be used to find the degree of similarity between the two documents is the semantic similarity. In fact, there is no document that doesn’t have a relationship with the other but their relationship might be close to 0. This method calculates the similarity between two documents by taking into account the level of similarity of words and their synonyms. After all inter-document similarity values obtained, a matrix will be created. The matrix is then used as a semi-supervised factor. The output of this method is the value of the membership of each document, which must be one of the greatest membership value for each document which indicates where the documents are grouped. Classification result computed by the method shows a good value which is 90 %. Index Terms - Fuzzy co-clustering, Heuristic, Semantica Similiarity, Semi-supervised learning.

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.

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 Comparison of Structure and Properties of Mo2FeB2-Based Cermets Prepared by Welding Metallurgy and Vacuum Sintering

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 46
Author(s):  
Hu Xu ◽  
Junsheng Sun ◽  
Jun Jin ◽  
Jijun Song ◽  
Chi Wang
Keyword(s):  
Wear Resistance ◽  
Corrosion Resistance ◽  
Volume Fraction ◽  
Phase Evolution ◽  
304 Stainless Steel ◽  
Vacuum Sintering ◽  
Cored Wire ◽  
Welding Metallurgy ◽  
Metallurgical Bonding ◽  
The Matrix

At present, most Mo2FeB2-based cermets are prepared by vacuum sintering. However, vacuum sintering is only suitable for ordinary cylinder and cuboid workpieces, and it is difficult to apply to large curved surface and large size workpieces. Therefore, in order to improve the flexibility of preparing Mo2FeB2 cermet, a flux cored wire with 70% filling rate, 304 stainless steel, 60 wt% Mo powder and 40 wt% FeB powder was prepared. Mo2FeB2 cermet was prepared by an arc cladding welding metallurgy method with flux cored wire. In this paper, the microstructure, phase evolution, hardness, wear resistance and corrosion resistance of Mo2FeB2 cermets prepared by the vacuum sintering (VM-Mo2FeB2) and arc cladding welding metallurgy method (WM-Mo2FeB2) were systematically studied. The results show that VM-Mo2FeB2 is composed of Mo2FeB2 and γ-CrFeNi.WM-Mo2FeB2 is composed of Mo2FeB2, NiCrFe, MoCrFe and Cr2B3. The volume fraction of hard phase in WM-Mo2FeB2 is lower than that of VM-Mo2FeB2, and its hardness and corrosion resistance are also slightly lower than that of VM-Mo2FeB2, but there are obvious pores in the microstructure of VM-Mo2FeB2, which affects its properties. The results show that WM-Mo2FeB2 has good diffusion and metallurgical bonding with the matrix and has no obvious pores. The microstructure is compact and the wear resistance is better than that of VM-Mo2FeB2.

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