Engineering and Technology Journal

In the present study, composites were prepared by Hand lay-up molding. The composites constituents were epoxy resin as the matrix, 3% volume fractions of Glass Fibers (G.F) as re enforcement and 2%, 4%, 6% volume fraction of micro powder (Aluminum Oxide Al2O3, Silicon Oxide SiO2 and Titanium Oxide TiO2) as filler. Studied the, hardness test, flexural strength, density, water absorption measurements and tests were conducted to reveal their values for each type of composite material. The results showed that the non – reinforced epoxy have lower properties than nano composites material. Measured density results had show an incremental increase with volume fraction increase and water absorption, hardness, and flexural strength had show an incremental increase with volume fraction increase and with smaller particle size.

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.

In the present study, composites were prepared by Hand lay-up molding The composites constituents were epoxy resin as a matrix, 6% volume fractions of Glass Fibers (G.F) as reinforcement and 3%, 6% volume fractions of preparation industrial powder (calcium carbonate CaCO3, potassium carbonate K2CO3 or sodium carbonate Na2CO3) as filler. The erosion wear behavior and coating by natural wastes (Rice Husk Ash) with epoxy resin after erosion were studied. The results showed that the non – reinforced epoxy have lower resistance erosion than industrial based Material composites and the specimen (Epoxy+6%glass fiber+6% CaCO3) has higher resistance erosion than composites reinforced with sodium carbonate and potassium carbonate at 25cm, angle 30°, grin size of sand 850µm, temperature 25Ċ, 200 gm salt content in 3liter of water and 15 hour. Coating specimen with mixed epoxy resin -RHA with particles size in the range (1.4-4.2) µm improves erosion wear resistance characteristics of the coated specimen, coating thickness was (16 ± 1) μm and after erosion in (15 hours) the thickness was (10) μm .Application of the work protection of pipes from erosion, these pipes include the sewage water , drainage pipe laboratory (hot water, chemicals and mineral oil) , pipeline transportation of petroleum products and pipeline transportation of gas products

In the present study composites were prepared by Hand lay-up molding. The composites constituents were epoxy resin as the matrix, 6% volume fractions of Glass Fibers (G.F) as reinforcement and 3%, 6% of nature material (Rice Husk Ash, Carrot Powder, and Sawdust) as filler. Density, water absorption, hardness test, flexural strength, shear stress measurements and tests were conducted to reveal their values for each type of composite. True density results had shown an incremental increase with volume fraction increasing and water absorption, hardness, flexural strength and shear stress results had shown an incremental increase with volume fraction increasing with smaller particle size.

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.

This study was carried out to investigate the effect of adding mica (5, 10, 15, 20, 25
% vf) with variable particle size (35, 57, 70μm) on the mechanical and electrical
properties of the unsaturated polyester composites. Some mechanical tests were carried
out like (impact strength, flexural strength) and dielectric strength. Flexural strength
and dielectric strength were found to increase with filler concentrations whereas impact
strength was found to decrease at higher concentrations for all particle size.

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.

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.

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

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.

This study was carried out to investigate the effect of the chemical
treatment of banana fibers on the physical properties of composites. Banana fibers
were treated with 10% sodium hydroxide and some physical tests were carried out
like: dielectric strength, dielectric constant, and thermal conductivity. The results
were compared with untreated fibers composites and virgin unsaturated polyester.
The results showed that the chemical treatment improved the dielectric strength
and thermal conductivity by about 29.37% and 139% respectively compared with
untreated fiber composites. Finally, the dielectric constant value of the treated
fiber composite was found to be lower than the untreated fiber composite and
virgin unsaturated polyester.

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.

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.

The aluminum alloys are important in many industrial applications
because of their light weight and good mechanical properties. For this reason
many researches had been done to enhance their properties. In this work a
modifier was applied to Al-12%Si alloys by adding different percentage of
Antimony powder (0.1, 0.2, 0.3, 0.4 and 0.5 Wt %). The mechanical properties of
the modified alloys were considered. The optimum properties were found by
adding 0.3% Antimony powder. This alloy was used as the matrix for the
production of composite material (aluminum matrix reinforced by ceramic
particles (Y2O3) with different weight percent (3,6,9 and 12%Wt)) using vortex
technique. The casting parameters were 3 minute as a mixing time and 300 r.p.m
as a mixing speed. The microstructure, hardness and wear test were applied on the
modified alloy and composite materials. The effect of the addition of Antimony
and reinforcement particles on the microstructure, hardness and wear rate of the
composite material were considered. The results show that the addition of
Antimony leads to the microstructure refinement and change the silicon shape in
the alloy from the flake – like or lamellar – like to fibrous – like In addition to the
increasing the hardness when Sb is up to 0.3%, after that the hardness will
decrease, as well as the addition of ceramic particles increase the hardness and
d e c r e a se the wear rate.

A three-dimensional study of developing fluid flow and heat transfer through
wavy and diverged-converged ducts were studied numerically for a Prandlt number 0.7
and 5.85 and compared with flow through corresponding straight duct. The Navier-
Stokes and energy equations are solved by using control finite volume method.
Development of the Nusselt number in wavy and diverged-converged ducts are
presented for different flow rates (50

Keywords

forced convection
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numerical study
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wavy duct
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diverged-converged duct

This research deals with the study the effect of adding the silica particles and
alumina particles separately with different ratio (5, 10, 15, 20, and 25 pphr) on the
hardness and wear rate of natural rubber NR and styrene butadiene rubber SBR. The
results show that the hardness increases with the increase the loading level of reinforcing
particles, while the wear rate decreases with the increase the loading level of the
reinforcing particles. The largest value of the hardness and the lowest value of the wear
rate were for styrene butadiene reinforced with 25 pphr of silica as compared with
natural rubber. Also the reinforcing by SiO2 increases the hardness and decreases the
wear rate more than of Al2O3.
The results indicated that the hardness and the wear rate for SBR and NR
reinforced by SiO2 and Al2O3 at (25 pphr) illustrated in the following table:

Taguchi method is a problem – solving tool which can improve the performance
of the product, process design and system. This method combines the experimental and
analytical concepts to determine the most influential parameter on the result response for
the significant improvement in the overall performance. In this research Al–Si /Al2O3
composites was prepared by vortex technique using three different parameters, stirring
time, stirring speed, and volume fraction of the reinforcement particles. A tensile and
hardness tests were done for the resulted castings. The primary objective is to use
Taguchi method for predicting the better parameters that give the highest tensile strength
and hardness to the castings, and then preparing composites at these parameters and
comparing them with the randomly used once. The experimental and analytical results
showed that the Taguchi method was successful in predicting the parameters that give
the highest properties and the volume fraction was the most influential parameter on the
tensile strength and hardness results of castings