Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : composites

The Effect of Ferrite Content on the Thermomechanical and Dielectric Strength Properties of Epoxy Composite

Lamees S. Faiq; Zahraa F. Attiyah

Engineering and Technology Journal, 2016, Volume 34, Issue 1, Pages 186-192

Different concentrations of cadmium ferrite (2%, 5%, 8%, 10% and 15%) were incorporated into epoxy resin. Cadmium ferrite was prepared by conventional ceramic technique. Composites are prepared by mixing the ferrite with epoxy by hand lay - up method at different percentages. The effect of ferrite content on tensile strength, hardness, thermal properties such thermal conductivity, thermal diffusivity and specific heat beside the dielectric strength were investigated. Using ferrite powders as filler to form particulate composite could lead to composite properties improvement. All the measured properties were improved with the increasing of the filler content. The results showed the important role of perfect adhesion between the filler and the polymer on the composite properties. It is found that the uniform distribution of filler particles in all directions of composite leads to the improved properties.

Water Absorption of HDPE/Al2O3,TiO2 Composites

Harith I. Jaffer; Z. R. Al-Shammary; Ali A. Abbas; Ali Qassim

Engineering and Technology Journal, 2015, Volume 33, Issue 7, Pages 1337-1347

The water absorption of high density polyethylene filled with micro hybrid (titanium dioxide and alumina), alumina and titanium dioxide with weight ratio of 15%, 20%, 25% and 30% , are measured in order to study the effect of these particles on water absorption of this polymer. The result shows that the increase of content of filler particles increasing water absorption, because of filler particles which have a higher water absorption percentage than the matrix material, and the filler will take up the free volume within the polymer matrix and create a tortuous path for the water permeating through the sample.

Evaluation Mechanical Properties of Polymer Composites Reinforced by different Metal Powders

Sihama Issa Salih; Safaa Nayyef; Alyaa H .Abd Alsalam; Ammar Mousa Hasan

Engineering and Technology Journal, 2015, Volume 33, Issue 7, Pages 1348-1360

This research covers reinforcement of unsaturated polyester resin by metal powders, and studying some of their mechanical properties. The samples were prepared by hand lay-out technique. The unsaturated polyester resin was reinforced by two types of metal powders Copper (15.598 µm) and aluminum (21.533µm) at selected volume fraction of (0, 5, 10. 15, 20 and 25 %). The study of mechanical properties includes tensile properties (strength at fracture point, elastic modulus and elongation at at break), flexural strength and flexural modulus, impact properties and hardness. The results show a noticeable increase in values of tensile strength at fracture point and tensile modules of elasticity, as the volume fraction of metal powder increase and reach to maximum value at 15 % volume ratio for both types, where as flexural strength, flexural modulus and fracture toughness reach to maximum value at 10 %volume ratio for both types composites, however elongation at break shows decrement as the volume fraction of metal powder is increased for both types composites.

Influence of Acidic and Salt Media on The Corrosion Behavior of Aluminum Matrix Composites Reinforced by Al2O3 Particles

Niven J.Abdal Kadir; Payman S.Ahmed; Saja Amer Abdul Majed

Engineering and Technology Journal, 2014, Volume 32, Issue 10, Pages 2351-2363

Corrosion behavior of pure Al and Al/ Al2O3 composite with five weight percent of Al2O3 particles (5,10,15,20 and 25) were investigated in 0.1M H2SO4 and 3.5 % NaCl solutions at room temperature. The composites were prepared by powder metallurgy and their corrosion behavior were evaluated by potentiostatic polarization and scan rate 3mV.sec-1.
It's observed that pure Al/Al2O3 composites exhibited excellent corrosion resistance in NaCl medium than in the H2SO4 media. The pure aluminum exhibited slightly superior corrosion resistance than the composites in NaCl medium but the composites had better corrosion resistance in H2SO4 medium.
Insulator Al2O3 particles are perceived to act as inert material and degrade the integrity of the protective oxide layer on the Al matrix.
Al/Al2O3 composites have lower corrosion rate than pure aluminum in 0.1 M H2SO4, but increasing of wt% of alumina led to increase the corrosion rate. While in 3.5% NaCl solution can be seen that corrosion rate of pure aluminum less than that for composites. Generlly, For certain material, the corrosion rate in salt medium less than in acidic medium.

Dielectric and Thermal Properties of Carrot Fibers –Epoxy Composites

Wafaa A. Hussain

Engineering and Technology Journal, 2011, Volume 29, Issue 16, Pages 3359-3367

Epoxy composites were prepared with two sizes of carrot fibers in different weight percent (10%, 20%, 30% and 40%) by hand lay-up technique. The dielectric constant and dissipation factor (tanä) of pure epoxy resin and composites were measured in a frequency range of 50 Hz to 5 MHz with increase fibers content, dielectric strength
(breakdown voltage) and thermal conductivity were evaluated as a function of fiber content. The dielectric constant and dissipation factor values were found to be higher for fiber reinforced system than the pure epoxy. The dielectric strength values decreases and the values of thermal conductivity increases with fibers content.

Effect of Heat Treatments on The Mechanical Properties And Wear Resistance of Al- Alloy Matrix Composite

Engineering and Technology Journal, 2011, Volume 29, Issue 12, Pages 518-533

Metal matrix composite (MMCs) of the base alloy (Al-0.978%Mg-1.03%Si) reinforced
with SiC particles (10 wt %) with particle size (53-106) μm was prepared by stir casting
using vortex technique. Solution heat treatment and aging are carried out at a constant
temperature of 175C° for different aging times. Many inspections and tests such as
microstructure, Vickers hardness and XRD analysis. Wear test type ( Pin – on – Disc) with
various applied loads and different exposure times at constant parameters was carried out
under dry sliding conditions.
It was found that the addition of SiC particles to base alloy improved the hardness and
wear resistance before and after heat treatment (precipitation hardening).
In addition, using SiC particles with alloy matrix resulted in a faster aging response i.e the
time of peak hardness decreased from 8hr to 5hr for base alloy and composite respectively.
These results indicate that the addition of SiC particles to Al –alloy matrix accelerates the
aging kinetic.

Ceramic Filled Polymer Matrix Composite Used For Bio-Medical Application

Waleed Asim Hanna; Abbas Khammas Hussei; Hayder Abbas Sallal

Engineering and Technology Journal, 2011, Volume 29, Issue 9, Pages 1765-1773

Synthetic polymers such as polyurethane are used widely in the field of
biomedical applications such as implants or part of implant systems.
This work focuses on the preparation of base polymer matrix composite
materials by (Hand Lay-Up) method ,and studying the effect of selected weight
fractions (3 , 6 , 9 , 12 ,15) % wt of Calcium oxide (CaO) , Calcium carbonate
(CaCO3), Magnesium oxide (MgO) ,and Magnesium carbonate (MgCO3) particles
on some properties of the prepared composite.
Some mechanical tests were used to evaluate the prepared system (Tensile,
Compression, Impact, and Hardness) tests, and a physical test of (Water
absorption %), and all tests were accomplished at room temperature.
maximum results of tensile strength, compression strength, impact energy,
hardness, water absorption were ( (31 MPa),( 51 MPa),( o.265 J), (79.8 Shor (D)),
(0.229 %)) at using ( (9% wt (MgCO3)) , ( 9% wt of (MgCO3)) , ( 9% wt of
(CaCO3)) , ( 15% wt of (MgO)) , ( 15% wt of (MgCO3)) respectively

Preparation and Characterization of Polymer- Ceramic Composite Bio-material

Rabab Asim Abdul-Aziz; Waleed Asim Hanna; Kahtan Khalaf Al-khazraji

Engineering and Technology Journal, 2010, Volume 28, Issue 13, Pages 2497-2515

This work focuses on studying the addition effect of the prepared HA powder as
a filler material before and after the calcination process with different volume
fractions (2.5, 5, 7.5, 10, 12.5, 15) vol% to the unsaturated polyester resin matrix.
Many mechanical and physical tests were used to determine the properties of the
prepared composite material which involved tensile strength, the modulus of
elasticity, the elongation percentage at break, compression strength, compression
modulus, bending strength, impact strength, fracture toughness, hardness and water
absorption percentage. For the prepared HA powder, the Ca/P ratio was increased
after the calcination process from 2.45 to 2.51. X- ray diffraction patterns for the
prepared HA powder before and after the calcination process revealed an increase
in the HA peak intensity after the calcination process. Secondary phases also
appeared after the calcination process like (α- Ca3(PO4)2 ) and (β- Ca2P2O7). For the
prepared composite material with both groups of HA filler particles, the results had
shown that the mechanical properties which included: tensile strength, modulus of
elasticity, compression strength, compression modulus, bending strength, fracture
toughness and hardness have been increased with increasing volume fraction of
HA filler particles and reached their maximum value at (7.5 vol%). Furthermore,
the increasing in volume fraction revealed a decreasing in the evaluated properties.
Both the elongation percentage at the break point and the impact strength
decreased with increasing volume fraction of HA filler particles. The water
absorption percentage as a physical property for the prepared composite material
showed an increase with increasing volume fraction of HA filler particles. The
improvement of unsaturated polyester resin with calcined HA filler particles had
shown greater values for the fore-mentioned properties than the improvement of
unsaturated polyester resin with uncalcined HA filler particles.

Evaluation of Observed Energy From Adiabatic Impact on Composite Lamenates

Kadhim H. Ghlaim

Engineering and Technology Journal, 2010, Volume 28, Issue 8, Pages 1545-1567

In this paper, the energy observed due to impact of conical projectiles on
composite laminates is investigated. Four types of energies observed were studied.
They are strain energy due to deformation of plate, large deformation near the
impact zone, delaminating energy and energy losses due to friction.
The equation of motion of plate was developed for orthotropic laminated
plate and solved with its boundary conditions. Large deformation of delaminated
zone was derived assuming deformation shape formulation to calculate the
penetration depth and delaminating radius. Delaminating energy was calculated
by solving the delaminating failure criteria with equation of motion. Friction
energy was calculated assuming constant friction coefficient.
The results show that the energy of deformation of plate is smaller than
that for the large deformation and delaminating energy. And as cone angle
increases the energy observed will be increased and the depth of penetration
decreases. Numerical and experimental results quoted in published papers show a
good agreement with that of the presented work.

Theoretical Aspects of some Mechanical Properties of Composites

Sabah S. AbdulNoor; Ahmad Al-Beiruti; Mustafa.H.Nashat

Engineering and Technology Journal, 2010, Volume 28, Issue 6, Pages 1128-1143

In the present wok, two mathematical models are constructed in order
to define the detailed nature of composite. The first one is based on the
classical Rule of Mixtures, (RoM) which is normally rotted from the ordinary
strength of materials. The second model is based on the theory of elasticity,
which deals with the detailed response of the internal macrostructure of the
composite. A virtual composite was assumed to be formed of a number of
matrices (Epoxy resin & Nickel) containing various inclusions (Carbon fibres
& powder, E-glass fibres & powder, and Kevlar fibres) in sequential
permutations. In general, the elasticity model E, exhibited various degrees of
superiority to the RoM depending on the mechanical parameters in question
and the mechanism by which it influences the internal details of the material.

Diffusion of various liquids to tubular shaped fiber reinforced composites

Hussein Ali Hamid AL-Abdly; Najat j. Salah; Adnan A. AbdulRazak; Hassen Sh. Majdi

Engineering and Technology Journal, 2008, Volume 26, Issue 8, Pages 919-937

In present work tubular –shaped fiber reinforced composites were
manufactured by using two types of resins ( Epoxy and unsaturated polyester) and
separately reinforced with glass, carbon and kevlar-49 fibers (filament and woven
roving), hybrid reinforcement composites of these fibers were also prepared. The
fibers were wet wound on a mandrel using a purposely designed winding machine,
developed by modifying an ordinary lathe, in winding angle of 55° for filament.
Various liquids were allowed to diffuse into the composite samples, where all
composite samples were immersed in water, HCl (0.5N, IN) and NaOH (0.5N, 1N).
The exhibited behaviors were mainly explained in accordance to Fick’s –law.
However, there were few case of anomalous behavior observed.
The observed difference in diffusion rate for acidic and basic solutions
may be explained in terms of different permeability of OH- and H+ ions in the
composite samples. This permeability was also found to be affected by the
debonding process which might be initiated by the liquid penetration. Diffusion
coefficients were also deduced and their relatively higher values are indicative for
some damage mechanism taking place in the composite and not the pure matrix.
UP composite exhibited higher values than EP composite which suggest that higher
damage has taken place in UP-composite.

Study the Adhesion Force of Tubular Shaped Fiber Reinforced Composites

Adnan A. AbdulRazak; Najat j. Saleh; Hussein Ali Hamid AL-Abdly

Engineering and Technology Journal, 2008, Volume 26, Issue 4, Pages 449-457

In the present work tubular –shaped fiber reinforced composites were
manufactured by using two types of resin epoxy (EP) and unsaturated polyester
(UP),each was separately reinforced with glass, carbon and kevlar-49 fibers (filament
and woven roving), hybrid reinforcement composites of these fibers were also
prepared. The adhesion force test of the prepared specimens was carried out. These
adhesion forces exhibited a peak value at a percent of hardener/resin (H/R)= 3% for
UP matrix with all type of fiber arrangements while 30% was obtained for EP matrix
.Such behavior was declined with increase in temperatures. Glass transition
temperatures were determined from these measurements, and found to be 90°C for EP–
glass and 83 °C for UP –glass composites.