Fractographic characterization of Al2O3p particulates reinforced Al2014 alloy composites subjected to tensile loading

In the current investigation, efforts are being made to produce an Al2014-Al2O3p composite with variable particle size of 88 mm by liquid stir casting route. 9, 12 and 15 weight proportions of Al2O3p were added to the Al2014 base alloy. By using SEM and EDS testing, microstructural studies have been conducted. Al2014-9, 12 and 15 weight proportion of Al2O3p composites mechanical behavior is determined in line with ASTM standards. Electron microscopic images showed that alumina (Al2O3p) particles are dispersed uniformly within the Al2014 composite matrix. EDS study confirmed the proximity of Al and O elements to composites reinforced by Al2O3p. It is also found that Al2014-Al2O3p composite hardness, UTS, and yield strength are improved by the addition of 9, 12 and 15 weight proportion of Al2O3p. Due to the addition of alumina particles in the Al2014 matrix alloy, the ductility of the produced composites decreases. Tensile fractography is performed using SEM to consider the mechanisms for failure.

Download Full-text

Synthesis, Characterization and Testing of Al Alloy Based Hybrid Composite Materials

International Journal of Innovative Technology and Exploring Engineering - Special Issue ◽

10.35940/ijitee.b1033.1292s219 ◽

2019 ◽

Vol 9 (2S2) ◽

pp. 139-142

Keyword(s):

Composite Materials ◽

Casting Process ◽

Stir Casting ◽

Homogeneous Distribution ◽

Al Alloy ◽

Matrix Composites ◽

Boron Carbide B4c ◽

Weight Proportion

The developments in the area of aerospace, advancing activities in aircraft field and automotive industry emerges the exploit of new materials. In such applications, the role of Metal Matrix Composites (MMCs) is inevitable. In the proposed article, the fabrication of Al (6351) alloy reinforced with SiC and varying weight proportion of Boron Carbide (B4C) was done through stir casting process. The characterization of prepared composite materials is evaluated to ensure the homogeneous distribution of reinforced particulates in Al matrix. The existence of alloying elements and their mapping is done through EDS. Moreover, the enhancement of physical and mechanical behavior of the fabricated composites is also discussed in detail.

Download Full-text

Experimental analysis on tribo-performance of aluminum composites

Journal of Composite Materials ◽

10.1177/0021998319900524 ◽

2020 ◽

Vol 54 (19) ◽

pp. 2577-2598 ◽

Cited By ~ 1

Author(s):

Santanu Sardar ◽

Susanta K Pradhan ◽

Santanu K Karmakar ◽

Debdulal Das

Keyword(s):

Wear Rate ◽

Base Alloy ◽

Stir Casting ◽

Ex Situ ◽

Electron Microscopic ◽

Material Loss ◽

Cu Alloy ◽

Wide Range ◽

Worn Surface

Two-body abrasion is of critical interest in engineering applications due to the severity of material and dimensional loss. In the present work, composites were manufactured through advanced stir-casting route by reinforcing Al-Zn-Mg-Cu alloy with 0 to 20 wt.% alumina particles. Microstructures of the developed materials were characterized through optical and field emission scanning electron microscopic examinations along with energy dispersive spectroscopy analyses besides measurements of porosity and Vickers hardness. Experimentation on two-body abrasion was carried out over a wide range of loads (20–80 N) and sliding velocities (0.125–1.50 m s−1) against silicon carbide abrasive medium. Tribological performances of base alloy and composites were assessed via evaluation of wear rate and coefficient of friction (COF) in addition to the estimation of surface roughness (SR) of abraded specimens. Composites exhibited higher SR, but lower wear rate and COF than alloy; the extents of those increased with raising reinforcement quantity. With rise in load, wear rate and abraded SR of the developed materials rose but COF decreased. Influence of sliding velocity was nominal on material loss for composites unlike base alloy, whereas SR was found to increase considerably and COF diminished slightly at higher velocities for all materials. Influences of various in-situ and ex-situ parameters on observed tribo-responses were explained through identification of different wear micromechanisms which were established via extensive postwear analyses of surface topography, worn surface, debris, and abraded paper.

Download Full-text

Effect of Reinforcement Type and Extrusion on the Microstructure and Mechanical Behavior of Al Alloy Composites

Volume 14: Emerging Technologies; Safety Engineering and Risk Analysis; Materials: Genetics to Structures ◽

10.1115/imece2015-50113 ◽

2015 ◽

Author(s):

Shanmuga Sundaram Karibeeran ◽

Dhanalakshmi Sathishkumar ◽

Balasubramanian Muthaih ◽

Sivakumar Palanivelu

Keyword(s):

Mechanical Properties ◽

Base Alloy ◽

Matrix Alloy ◽

Stir Casting ◽

Extrusion Process ◽

Al Alloy ◽

Matrix Composites ◽

Tension Tests ◽

Cast Composites ◽

The Matrix

Aluminum based metal matrix composites offer greater potential for light weight, wear resistant and high temperature applications. Secondary processing like extrusion results in the improvement of strength and ductility of the as-cast composites. The objective of this research is to investigate the effect of reinforcement type and extrusion process on the microstructure and mechanical properties of the hot extruded Al2014 aluminum alloy. Two different composites were made by reinforcing the alloy with 10 wt.% SiC and 10 wt.% Si3N4 particles using stir casting method. The particles were electroless Ni coated to improve the wettability of reinforcement by the matrix alloy. The composite ingots were further extruded at 475 °C with an extrusion ratio of 8:1. The microstructures and the mechanical properties of the base alloy and the composites were examined systematically. The extruded composites show more homogenous microstructure with uniform distribution of particles in the matrix alloy. Both the Al/SiC and Al/Si3N4 composites exhibited improved hardness compared to the base alloy in both as-cast and extruded conditions. It was also found from tension tests that the both the composites show higher yield strength, ductility and ultimate tensile strength (UTS) than the base alloy in the extruded condition. The reason for improvement in strength in the extruded conditions is explained in detail. Fracture surface analysis revealed the transition from brittle fracture mode in the as cast composites to the ductile fracture in the extruded condition.

Download Full-text

Influence of Gr, MoS2 and BN on the Hardness and Wear resistance of AA2014 Hybrid Composite after Artificial Aging

International Journal of Innovative Technology and Exploring Engineering - Special Issue ◽

10.35940/ijitee.j9784.0881019 ◽

2019 ◽

Vol 8 (10) ◽

pp. 3608-3613 ◽

Cited By ~ 1

Keyword(s):

Wear Rate ◽

Base Metal ◽

Hybrid Composite ◽

Base Alloy ◽

Research Work ◽

Stir Casting ◽

X Ray Diffraction ◽

X Ray ◽

Casting Technique

The main objective of this research work is to study the effect of tribological behaviors and mechanical properties of Aluminium alloy 2014 (AA2014) hybrid composite reinforced with Boron Nitride (BN), Molybdenum disulfide (MoS2) and graphite (Gr). Stir casting technique is used for the fabrication of this composite material. The composite is subjected to three step ageing process which consists of solution heat treatment, quenching and aging. The base alloy was reinforced with 4 wt.% of BN, 4wt.% MoS2 and 4, 6, 8 wt.% of Gr. The hardness of the composite steadily increased up to 6 wt. % of graphite and further increase in graphite decreases the hardness. The sample with Graphite of 4 wt. % resulted in maximum hardness of 192 HV with respect to AA2014 base hardness. Addition of graphite up to 6% resulted in lower wear rate when compared to the base metal. The wear rate of sample with Graphite of 4 wt. % is reduced by 49 % from that of the base metal at maximum wear condition. Scanning Electron Microscope (SEM), Energy-dispersive X-ray Spectroscopy (EDX) and X-Ray Diffraction (XRD) were used for the characterization of composite.

Download Full-text

Electron Microscopic Detection and Characterization of Nonhuman Primate Enteric Viruses

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100054145 ◽

1982 ◽

Vol 40 ◽

pp. 306-307

Author(s):

G. C. Smith ◽

R. L. Heberling ◽

S. S. Kalter

Keyword(s):

Electron Microscopy ◽

Animal Model ◽

Nonhuman Primate ◽

Clinical Condition ◽

Intestinal Tract ◽

Enteric Viruses ◽

Electron Microscopic ◽

Microscopic Detection

A number of viral agents are recognized as and suspected of causing the clinical condition “gastroenteritis.” In our attempts to establish an animal model for studies of this entity, we have been examining the nonhuman primate to ascertain what viruses may be found in the intestinal tract of “normal” animals as well as animals with diarrhea. Several virus types including coronavirus, adenovirus, herpesvirus, and picornavirus (Table I) were detected in our colony; however, rotavirus, astrovirus, and calicivirus have not yet been observed. Fecal specimens were prepared for electron microscopy by procedures reported previously.

Download Full-text

The Immuno-Electron Microscopic Localization of the Mo-Fe Protein Component of Nitrogenase in Cells of Azotobacter Vinelandii

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100073313 ◽

1973 ◽

Vol 31 ◽

pp. 574-575

Author(s):

J. T. Stasny ◽

R. C. Burns ◽

R. W. F. Hardy

Keyword(s):

Cellular Localization ◽

Direct Evidence ◽

Azotobacter Vinelandii ◽

Intracellular Localization ◽

Protein Component ◽

Electron Microscopic ◽

Thin Sections ◽

Fe Protein ◽

Intracytoplasmic Membranes

Structure-functlon studies of biological N2-fixation have correlated the presence of the enzyme nitrogenase with increased numbers of intracytoplasmic membranes in Azotobacter. However no direct evidence has been provided for the internal cellular localization of any nitrogenase. Recent advances concerned with the crystallizatiorTand the electron microscopic characterization of the Mo-Fe protein component of Azotobacter nitrogenase, prompted the use of this purified protein to obtain antibodies (Ab) to be conjugated to electron dense markers for the intracellular localization of the protein by electron microscopy. The present study describes the use of ferritin conjugated to goat antitMo-Fe protein immunoglobulin (IgG) and the observations following its topical application to thin sections of N2-grown Azotobacter.

Download Full-text

High-resolution transmission electron microscopic study of highly oxygen doped silicon layer

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100155438 ◽

1989 ◽

Vol 47 ◽

pp. 692-693

Author(s):

H. Takaoka ◽

M. Tomita ◽

T. Hayashi

Keyword(s):

High Resolution ◽

Oxygen Concentration ◽

Silicon Layer ◽

Detailed Structure ◽

Electron Microscopic ◽

Cross Sectional ◽

Transmission Electron ◽

Doped Silicon ◽

Argon Ion

High resolution transmission electron microscopy (HRTEM) is the effective technique for characterization of detailed structure of semiconductor materials. Oxygen is one of the important impurities in semiconductors. Detailed structure of highly oxygen doped silicon has not clearly investigated yet. This report describes detailed structure of highly oxygen doped silicon observed by HRTEM. Both samples prepared by Molecular beam epitaxy (MBE) and ion implantation were observed to investigate effects of oxygen concentration and doping methods to the crystal structure.The observed oxygen doped samples were prepared by MBE method in oxygen environment on (111) substrates. Oxygen concentration was about 1021 atoms/cm3. Another sample was silicon of (100) orientation implanted with oxygen ions at an energy of 180 keV. Oxygen concentration of this sample was about 1020 atoms/cm3 Cross-sectional specimens of (011) orientation were prepared by argon ion thinning and were observed by TEM at an accelerating voltage of 400 kV.

Download Full-text

Electron microscopic characterization of diamond thin films and substrates for diamond heteroepitaxial growth

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100154937 ◽

1989 ◽

Vol 47 ◽

pp. 592-593

Author(s):

J.B. Posthill ◽

R.P. Burns ◽

R.A. Rudder ◽

Y.H. Lee ◽

R.J. Markunas ◽

...

Keyword(s):

Thin Films ◽

Wide Band ◽

Deposition Process ◽

Heteroepitaxial Growth ◽

Electron Microscopic ◽

Wide Band Gap ◽

Lattice Matching ◽

Different Types ◽

Diamond Thin Films

Because of diamond’s wide band gap, high thermal conductivity, high breakdown voltage and high radiation resistance, there is a growing interest in developing diamond-based devices for several new and demanding electronic applications. In developing this technology, there are several new challenges to be overcome. Much of our effort has been directed at developing a diamond deposition process that will permit controlled, epitaxial growth. Also, because of cost and size considerations, it is mandatory that a non-native substrate be developed for heteroepitaxial nucleation and growth of diamond thin films. To this end, we are currently investigating the use of Ni single crystals on which different types of epitaxial metals are grown by molecular beam epitaxy (MBE) for lattice matching to diamond as well as surface chemistry modification. This contribution reports briefly on our microscopic observations that are integral to these endeavors.

Download Full-text