PROJE FUARI 2009
________________________________________________________________
IMPROVEMENT THERMAL AND MECHANICAL PROPERTIES OF
CORDIERITE GLASS-CERAMICS
Aybike ÜRKMEZ
Supervisor: Assost. Dr. Semra KURAMA
Department Of Materıals Scıence And Engıneerıng
Faculty of Engineering and Architecture, Anadolu University
Iki Eylül Campus, 26555, Eskisehir
The effects of the system of Strontium-Aliminum-Silicate (SAS) on cordietire glassceramics and mechanical properties are examined in this project. SAS is added to cordierite
system with % 1-5 weight fraction and sintered at 1200°C, 1250°C and 1300°C. In density
measurement due to the Archimedes principle, while sintering temperature and SAS amount
was increasing, increasing on the density has seen ( density value of pure kordiyarit is 1.7
g/cm3 and for %5 SAS is 2.1 g/cm3). By the way, increasing of these parameters decrease the
water absorbtion, and also mechanical properties increase with increased SAS amount.
Keywords: Cordierite-based glass ; Strontium-Aluminum-Silicate; Thermal conductivity;
Mechanical Properties
MLZ-1
PROJE FUARI 2009
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THERMAL CONDUCTIVITY OF α-β SiALON CERAMICS WITH SEGREGATED
NETWORK OF SiC PARTICLES
Aynur GEREDE
Danışman: Doç.Dr.Alpagut KARA
Department Of Materıals Scıence And Engıneerıng
Faculty of Engineering and Architecture, Anadolu University
Iki Eylül Campus, 26555, Eskisehir
In this particular work the effect of segregated network of SiC particles on the thermal
conductivity of α-β SiAlON ceramics were reported. Apart from conventional particle
reinforced composite approach, formation of a segregated network of SiC particles in the βSiAlON matrix is achieved by employing a simple mechanical mixing of SiAlON granules
and nano SiC particles. SiAlON granules that have commercial name 25A were obtained by
spray drying. Samples were prepared within four different amount of SiC(2.5, 5,7.5,10
volume %). Composite powders were sintered by gas pressure sintering (GPS) and spark
plasma sintering methods. In order to determine thermal conductivity of the prepared samples,
thermal diffusivity and heat capacity values were obtained by using laser flash and differential
thermal analysis (DTA) respectively. Additionally mechanical behavior of the materials was
investigated in terms of hardness and fracture toughness by using Vickers indentation method.
In conclusion it was found that thermal conductivity of composites strongly depends on the
sintering method. Thermal conductivity values of GPS samples was higher than SPS samples
due to the phase formations. Also with this new approach by decreasing percolation point of
the material higher thermal conductivity values can be obtained by low amount of SiC
additions.
MLZ-2
PROJE FUARI 2009
___________________________________________________________________________
LOW COST WALL TILE GLAZES
Eyyüp Baki SANDAL
Supervisor: Assoc.. Prof. Emrah DÖLEKÇEKİÇ
Department Of Materıals Scıence And Engıneerıng
Faculty of Engineering and Architecture, Anadolu University
Iki Eylül Campus, 26555, Eskisehir
The whitness, opacity, smooth surface texture and glossiness of wall tile glazes are
most usually provided by the usage of zircon containing frtis. On the other hand the change in
demand – supply balances of Zircon mines has been caused to increase the cost of this
material and its is to be known that according to the performed studies the replacement of the
Zircon with appropriate raws offers to decrease the production costs with significant values.
In this study its observed that the occured glass-ceramic systems which are perfomed
by optimizing Al2O3/alkali and CaO/MgO ratios.
According to the required characterization methods the resulatant structures, phases
,the efficiency of the study and its effect on cost is evaulated.
Keywords: wall tile, glaze, fast firing, Zircon-free, cost
MLZ-3
PROJE FUARI 2009
_________________________________________________________________________
CORDIERITE BASED WATER FILTER
Betül OKUR
Supervisor: Assist. Prof. Dr. Semra Kurama
Department Of Materıals Scıence And Engıneerıng
Faculty of Engineering and Architecture, Anadolu University
Iki Eylül Campus, 26555, Eskisehir
In this study, feature of the porous structure of cordierite ceramic has been addressed
through the use microfiltration. PVA (Polivinylalcohol) was used in order to obtained desired
porosity. Water permeability and particle filtration properties were conducted according to
pore size and porosity of prepared samples. After the raw materials had been mixed, planetary
milling was used for grinding, and then uniaxial press was done to the powders. Samples were
sintered for various temperatures such as between 1100-1300 ⁰C. Cordierite phase was
determined at temperatures 1250 and 1300 ⁰C. Weight loss, bulk density, apparent density, %
porosity, and % water absorption of samples were measured by Archimedes Method.
Measurement of pore size and distribution were done by mercury porosimeter. Phase analysis
of sintered samples were characterized by X-ray diffraction (XRD) and microstructure of
sintered samples were determined by scanning electron microscope (SEM). Thermal stability
of the starting material was determined by thermogravimetric analysis device (TGA).
According to applied tests and results, weight loss and density increase with increasing
sintering temperature, but pore size and porosity decreases with increasing sintering
temperature. As a result, permeability decreases with increasing temperature depending on
porosity.
Keywords : Cordierite, porosity, filter, permeability
MLZ-4
PROJE FUARI 2009
_________________________________________________________________________
TRANSMISSION ELECTRON MICROSCOPE (TEM) CHARACTERISATION OF
Si3N4-Al COMPOSITES
Ekin SIMSEK
Supervisor Prof. Dr. Servet TURAN
Department Of Materıals Scıence And Engıneerıng
Faculty of Engineering and Architecture, Anadolu University
Iki Eylül Campus, 26555, Eskisehir
Ceramic materials have some superior properties like high hardness, good
mechanical properties and low density, to take advantages of these and improve the fracture
toughness of ceramic materials, composites are produced. Si3N4-Al composites are used
many critical application such as; aviation, electronic, automotive. After one-way pressing
applied to Si3N4 powders for pre-shaping and porous pellets densify with cold isostatic
pressing; with using 7075 Al alloy pressureless infiltration is implemented in horizontal tube
furnace, at 1200°C temperature and Ar gas atmosphere. According to the literature when
Si3N4 and Al react, AlN and metallic silicon phases are formed. Sample preparation process
is very important for TEM characterisation. Slices which have about 400µm thickness are cut
and grinded with using 120 and 180 grid SiC papers, so their thickness are decrease to
150µm; with using ultrasonic disc cutter 3mm diameter discs are obtained and with 9, 6, 3 µm
diamond lapping films tripod polishing is done and thickness of samples become 30 µm.
Sample thickness is get thinner under 100nm with ion milling. Micrographs are obtained from
TEM bright field (BF) and dark field (DF), and also scanning electron microscope (STEM)
DF and BF; chemical analysis is done with STEM energy dispersive X rays (EDX).
Aluminum oxynitride (AlON) is seen as a formed phase after analyses. Results from this
study are presented.
Keywords: Composite, Characterisation, TEM
MLZ-5
PROJE FUARI 2009
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OPTICAL PROPERTIES OF α -SiAlON CERAMICS
Emre KOCA
Supervisor Prof. Dr. Hasan MANDAL
Department Of Materıals Scıence And Engıneerıng
Faculty of Engineering and Architecture, Anadolu University
Iki Eylül Campus, 26555, Eskisehir
In this thesis, effect of rare earth elements and milling time on the luminescence
properties of Ca- α-SiAlON ceramics were investigated. Rare-earth-doped α-SiAlON
compounds have been reported to be luminescent and may then serve as new materials in
different application areas with good thermal and chemical stabilities. In present work,
compositions were Ca1-xRExSi12-m-nAlm+nOnN16-n ( with m=2, n=1, x=0.0296) and Yb
and Sm used as a rare earth elements. Compositions were prepared by millig 90 and 240
minutes with planatory ball mill and sintered at 1790 °C for 1 hour under 22 bar in nitrogen
atmosphere. Their particle sizes measured by using lazer diffraction method and
photoluminescence (PL) properties were measured by using flourescence spectrophotometer.
İncreasing of the milling time, resulted to decreasing of particle size in both compositions.
Emission wavelenghts of the Sm doped compositions were measured 537 nm and 550.5 nm.
Emission wavelenghts of the Yb doped compositions were measured 538.9 nm ve 539 nm.
Keywords: α-SiAlON Ceramics, Samarium, Ytterbium, Luminescence Properties, Milling
Time
MLZ-6
PROJE FUARI 2009
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PROTOTYPE CAR WITH WORKING HYDROGEN ENERGY
Ergün BİÇER
Burak DELEN
Supervisor Prof. Dr. Aydın DOĞAN
Department Of Materıals Scıence And Engıneerıng
Faculty of Engineering and Architecture, Anadolu University
Iki Eylül Campus, 26555, Eskisehir
In this thesis, effect of rare earth elements and milling time on the luminescence
properties of After the industrial revolution, because of using of the fossil fuel increases day
by day and therefore, alternative energy sources start to research. Highest priority sources as
solar, wind and hydrogen recur to mind. Thanks to hydrogen has a lot of advantages like
enviroment-friendly high efficiency, most of person think first energy sources that is
hydrogen in the future time. Modern fuel cell is firstly used and then improved at the end of
the 19th , it has been used in the used with hydrogen energy.
Car competition with hydrogen organize from The Scientific and Technological
Research Council of Turkey in 2007, in order to draw attention to hydrogen subject and cheer
student to this topic. Anadolu University Hydrocar Project Team first attent to this race with
a car which is name “Hidroana”, and succeed 3rd position at the finished line in 2008. It
embodies with this result due to get ahead of other important university as İTÜ, Boğaziçi,
Bilkent,Yıldız.
After with high efficiency new design prototype car which is name “Hidroana
Revolution” aim of team increased and attended Shell Eco Marathon Europe race at 7-9th of
May 2009 in Germany. This race had big experience for team although any success. Team
aim advanced achievement rather than that have own success from last year.
Keywords: Renawable energy sources, Hydrogen Energy, The race of Hydrocar of The
Scientific and Technological Research Council of Turkey, Shell Eco-marathon Europe
MLZ-7
PROJE FUARI 2009
_________________________________________________________________________
COST-EFFECTIVE PRODUCTION OF SiAlON CERAMICS
Fatih ERTÜRK
Supervisor: Prof. Dr. Ferhat KARA
Department Of Materıals Scıence And Engıneerıng
Faculty of Engineering and Architecture, Anadolu University
Iki Eylül Campus, 26555, Eskisehir
SiAlON ceramics have a high potential for engineering applications due to their good
mechanical and chemical and thermal properties. In this study, dense but, low-cost producing
of SiAlON ceramics were aimed. For this aim, the compositions were prepared from low-cost
Si and Si3N4 powders. Powders were pelletized with cold isostatic pressing. Without
changing the composition, with changing particle size, pressure and temperature values,
sintering behaviours were examined. The Si and Si3N4 powders which were milled to 1 and 2
μm particle sizes, were nitrided at 1400 ºC with using AlN-Al2O3-CeO2-CaCO3 additive
combination. Heat treatment was used as gas pressure and pressureless at 1850 ºC, 1940 ºC
and 1990 ºC’de for each sintering. With increasing pressure, it was seen to decrease open
pores and it was reached to high relative density values at approximately %99.57 values.
Also, it was observed to enhance fracture toughness values.
MLZ-8
PROJE FUARI 2009
_________________________________________________________________________
INVESTIGATION OF COLLOIDAL PROPERTIES OF VANADIUM DOPED
ZIRCON PIGMENTS
Fahri S. BOYLU
Supervisor: Assist. Prof. Dr. Emel ÖZEL
Department Of Materıals Scıence And Engıneerıng
Faculty of Engineering and Architecture, Anadolu University
Iki Eylül Campus, 26555, Eskisehir
Zircon (ZrSiO4) pigments are commonly used in the ceramic industry for glazes due
to their high chemical stability and superior resistance to the dissolution during firing in
glazes. These pigments are made by calcining a mixture of SiO2, ZrO2, a dopant ion which
produces the colour and a mineralizer. Turquosie blue zircon pigments containing vanadium
is produced commercially.In this project, vanadium doped zircon blue pigments was studied.
Stabilization of zirconia in aqueous suspension and solubility of V-Zr pigments in water was
investigated.The used raw materials zirconium dioxide (ZrO2), silicon dioxide (SiO2),
vanadium oxide (V2O6) are mixed. The prepared compositions were calcinated at 1100 °C to
pigments. The phases of the prepared pigments after calcination were analysed by using x-ray
diffraction (XRD). The pigment powders were milled with a plantary mill in alumina cups
with 350 rpm several minutes to achieve intended grain size which is 5.7 µm. ICP and IR was
determined. Conductivity and zeta potantial were also determined.
Keywords: ZrO2, SiO2, V2O6, Calcination, Pigment, Grain size, XRD, IR, ICP,
Conductivity, Zeta potantial, Vanadium doped Zircon, Blue pigment.
MLZ-9
PROJE FUARI 2009
_________________________________________________________________________
UTILIZATION OF COPPER ALLOY PRODUCTION WASTES
Gözde Ece AYDEMİR
Lütfullah Oguzhan GEZ
Supervisor Prof. Dr. Nuran AY
Department Of Materıals Scıence And Engıneerıng
Faculty of Engineering and Architecture, Anadolu University
Iki Eylül Campus, 26555, Eskisehir
Slag which is formed from copper alloy (brass) production contains oxides of copper,
zinc. and other elements. Slag is first processed in mill and brass is recovered. By-product of
milling process is a waste which it includes zinc and other elements oxides and is called mill
ash. Also another ash called fly ash. Ceramic wall tiles are used in terms of decorative and
technical aim as glazed. Zinc oxide and various oxides are in glaze component. In this study,
mill ash and fly ash used in the transparent glaze compositions instead of zinc oxide and its
effect on glaze properties was investigated. Standard frit has 9% zinc oxide. Frit samples were
prepared in which 10, 20 and 30% of zinc oxide was from mill ash and fly ash. Frit was
melted at 1450⁰ C and was grinded after quenching. Recipe of glaze containing 95% ground
frit was applied on wall tile. Glazed wall tiles were sintered at 1135⁰ C for 35 minutes.
Hardness, brightness, color, XRD and SEM-EDS analyses were carried out. Results show that
the amount of mill ash or fly ash in glaze composition can not change hardness value and
increase brightness. The color of wall tile glaze was transformed from white to blue green
with addition of mill ash
Key words: Zinc oxide, Waste recovery, Transparent glaze, Ceramic wall tile
MLZ-10
PROJE FUARI 2009
________________________________________________________________________
NANO COATINGS FOR BIOMIMETIC DEVICES:
GMR SPIN VALVE SENSORS FOR DNA SENSING
Hasan SATILMIŞ
Supervisor: Assc. Prof. Dr. R. Mustafa ÖKSÜZOĞLU
Department Of Materıals Scıence And Engıneerıng
Faculty of Engineering and Architecture, Anadolu University
Iki Eylül Campus, 26555, Eskisehir
In this theoretical sudy type and models of magnetoresistance (GMR) spin valve
sensors usable for detection of DNA molecules via sensing of superparamagnetic
nanoparticles as potential biomolecular labels in magnetic biodetection technology were
studied. In this paper spin valve sensors as highly sensitive biosensors and monodisperse
superparamagnetic nanoparticles as magnetic labels for emerging magnetic biodetection
technology, detection principles of sensors were presented. In researched papers the scientists
achieved higher than 17% electrical resistance difference by the gmr spin valve sensors with
paramagnetic nanoparticles for DNA chain molecule detection.
Keywords: Spin valve sensor, GMR, Magnetic nanoparticle, Biodetection, Biosensor, Spin
vana sensörü, GMR, manyetik nanopartikül, biyoalgılama, biyosensör.
MLZ-11
PROJE FUARI 2009
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AlN-B4C-Al CERAMIC MATRIX COMPOSITES
İrem Cansu KALPAKÇI
Hülya BÖLEK
Supervisor: Asst. Prof. Dr. Gürsoy ARSLAN
Department Of Materıals Scıence And Engıneerıng
Faculty of Engineering and Architecture, Anadolu University
Iki Eylül Campus, 26555, Eskisehir
In this study, it was aimed to investigate electrical and thermal properties of
pressureless melt infiltrated AlN-B4C-Al composites. All composites were produced at
and metal type on the thermal and electrical conductivity of the produced composites are
investigated. B4C content of the composites were between 20-50 wt.% depending on the
designed compositions. Pure Al and 2024 Al alloy were used to infiltrate the porous AlN-B4C
preforms. Open porosi
the samples were carried out by scanning electron microscopy (SEM). SEM investigations
revealed that the microstructures of the composites were homogeneous. X-ray diffraction
analyses (XRD) showed that AlN, B4C, Al and Al3BC are the main phases in the produced
composites. Thermal diffusivity and heat capacity of the produced composites will be
measured by the laser flash and differential scanning calorimetry (DSC) techniques,
respectively. Thermal conductivity of the ceramic-metal composites will be calculated by
using these data. Impedance method will be used to measure electrical conductivity of the
produced composites.
Keywords: thermal conductivity, electrical conductivity, ceramic-metal composite, particle
size,composition
MLZ-12
PROJE FUARI 2009
APPROACHES FOR NANO-SIZE PARTICLES AND THEIR SAFE USAGE
Fatih PİŞKİN
Advisor: Assoc. Prof. Dr. Ender SUVACI
Department Of Materıals Scıence And Engıneerıng
Faculty of Engineering and Architecture, Anadolu University
Iki Eylül Campus, 26555, Eskisehir
Titanium dioxide (TiO2) has high absorbance behaviour, especially for the lower
wavelengths of solar light (290-320 nm) and since the usage of nanosized particles; it shows
great cosmetic compatibility and higher absorbance values. That’s why it is the main physical
barrier component for sunscreens which have high sun protection factor. However, combining
the skin penetration with photocatalytic behaviour of TiO2 which caused by absorbing the
energy from solar light, TiO2 may cause skin cancer by damaging human via cells and DNA.
Considering the higher photocatalytic behaviour of nanosized particles, it is required to
examine the photocatalytic activity and the skin penetration of TiO2 which have limited study
in literature, to provide safe usage of nanosized TiO2 in sunscreens.
In this study, it is aimed to eliminate or reduce the potential skin penetration of TiO2,
which makes the resultants of photocatalytic activitiy of TiO2 insignificant; micron sized
controlled agglomerates that are still consisting of nanosized TiO2 particles would be
produced to provide safe usage of TiO2 in sunscreens. Preventing the skin penetration of TiO2
would be the approach that avoids the potential hazardous effects on via cells and DNA. For
this study, it was tried to provide control agglomeration by heat treatment with certain
organics.
In order to characterize and get information about phase composition of particles which
exposed to heat treatment, Fourier Transform Infrared (FTIR) and X-ray diffraction (XRD)
method was used. For the morphological information, scanning electron microscope (SEM)
was utilized.
MLZ-13
Keywords: TiO₂, sunscreen, agglomeration, photocatalytic activity
PROJE FUARI 2009
_________________________________________________________________________
THE EFFECT OF COMPACT THICKNESS ON NITRIDATION OF SILICON
Melih ÖZÇATAL
Yiğit ATTİLA
Supervisor Prof. Dr. Ferhat KARA
Department Of Materıals Scıence And Engıneerıng
Faculty of Engineering and Architecture, Anadolu University
Iki Eylül Campus, 26555, Eskisehir
SiAlON ceramics have a high potential for structural applications due to their good
mechanical, chemical and thermal properties. SiAlON ceramics are used in applications such
as cutting tools, refractory materials and ball bearings. In this study reaction bonding process
was used to produce dense sialon ceramics with a relatively low cost. A mixture of Si and
Si3N4 powder was used to prepare the compositions. Powders were pelletized with uniaxial
pressing and cold isostatic pressing. Two different nitridation processes is applied. The first
one is nitridation at 1350 0C, by keeping the temperature constant about 2 hours. The second
one is nitridation beginning at 1150 0C, then slowly increasing the temperature (first 100 0C
then 50 0C about 30 minutes) until 1350 0C. The efficiency of these two techniques was
compared. Nitridation is followed by a sintering process at 1950 0C under 5 bar pressure and
1990 0C under 10 bar pressure. At the end of the study XRD and SEM techniques were
applied to decide optimum processing parameters.
Keywords: SiAlON, Si and Si3N4 powder, Reaction Bonding
MLZ-14
PROJE FUARI 2009
_________________________________________________________________________
TEXTURE EVOLUTİON IN DEFORMATİON OF MAGNESİUM ALLOYS
AND ITS ASSESSMENT USİNG X-RAYS
Murat EROĞLU
Supervisor Prof. Dr. Ferhat KARA
Department Of Materıals Scıence And Engıneerıng
Faculty of Engineering and Architecture, Anadolu University
Iki Eylül Campus, 26555, Eskisehir
Magnesium alloys have a great potential in automotive industries, compared to steel
and aluminium (Al), Magnesium (Mg) is much lighter and this weight reduction improves
fuel efficiency and lowers green gas emission. Due to its hexagonal crystal structure,
magnesium has poor ductility at room temperature.
Magnesium's ductility improves
significantly above about 200°C due to thermal activation of additional slip systems. In this
study, texture evolution of magnesium alloy sheets in different deformation processes were
researched by X-ray pole figure technique. It is observed that the texture of magnesium alloy
sheets prefers the basal texture, and other compositions of texture are relatively weak
MLZ-15
PROJE FUARI 2009
________________________________________________________________________
THE USAGE OF ISTANBUL COALED CLAYS IN PORCELAIN
TILE PRODUCTION
Murat TARCAN
Advisor: Assoc. Prof. Dr. Alpagut KARA
Department Of Materıals Scıence And Engıneerıng
Faculty of Engineering and Architecture, Anadolu University
Iki Eylül Campus, 26555, Eskisehir
It is well known that clays are important constituents of ceramic tile bodies. An
optimum combination of various clays provide plasticity and green strength during forming
stages and contribute substantially to the colour of the fired products depending upon the
impurity oxides present. With the increased production rate in ceramic tile manufacturing,
new alternative clays are needed in the whole ceramic sector. Due to this, new clays deposits
and their investigation had become and important issue for the producers. In this study, the
clay deposits near Şile region were investigated. Firstly, the clay samples were characterised
using with XRF and XRD. In order to study the thermal properties of the clay samples,
TGA/DTG measurements were carried out. Finally standard tests were applied to the
porcelain tiles obtained from the experimental bodies incorporated with varying amounts of
clay samples after single fast-firing under industrial conditions. The results showed that, it
was possible to use of İstanbul coaled clays into porcelain tile formulations
Keywords: Coaled clay, Porcelain tile, Characterisation
MLZ-16
PROJE FUARI 2009
_________________________________________________________________________
EXPERIMENTAL SETUP FOR GIANT MAGNETORESISTANCE
MEASUREMENTS
Okan DENİZ
Assoc. Prof. Dr. R. Mustafa ÖKSÜZOĞLU
Department Of Materıals Scıence And Engıneerıng
Faculty of Engineering and Architecture, Anadolu University
Iki Eylül Campus, 26555, Eskisehir
Giant magnetoresistance (GMR) is an effect which is observed in thin film multilayer
structures composed of two ferromagnetic material and a metal between them. The idea of
GMR is basically providing an extra electrical resistivity by changing the magnetic
orientation of the spins of the electrons. An increase electrical resistivity can be provided
when the spin of the electrons which is passing through the material by current is opposite to
the spin direction of spin of the material’s electrons. The magnetic orientation of spin can be
changed by applying an external magnetic field. By changing the magnetic orientation of the
materials electrons we gather a difference between the resistivities from one applied magnetic
field direction to another, called Magnetoresistance Effect. For understanding the GMR effect
measurement the electrical characterization is important. For the thin film structures, “four
point probe” technique is common to measure the sheet resistance. In this project, the
experimental setup consisting self made FPP and Helmholtz Coil was utilized for GMR effect
measurements. The specifications, parameters, problems, especially the integration of four
point probe technique into the Helmholtz coil (magnetic field provider) and the possible
solution suggestions will be considered and discussed.
MLZ-17
PROJE FUARI 2009
OPTICAL PROPERTIES OF OXYNITRIDE GLASS
Orçun PEŞKİRCİ
Advisor: Asst. Prof. Dr. Emrah DÖLEKÇEKİÇ
Department Of Materıals Scıence And Engıneerıng
Faculty of Engineering and Architecture, Anadolu University
Iki Eylül Campus, 26555, Eskisehir
Oxynitride glass is found at the intergranular phases in the Si3N4 based ceramics in
which oxygen atoms replaced by the nitrogen atoms. Glass network is more strength than the
other glass due to the nitrogen makes 3 bonds instead of the oxygen makes the 2 bonds. Due
to that, oxynitride glass has high mechanical properties. Also, oxynitride glass has high
thermal properties, high chemical durability and electrical insulator properties with respect to
glass batch. In these days, special glasses which have not high mechanical properties
corresponding to the oxynitride glass are used for optical and electrical systems. According to
the mechanical properties, oxynitride glass can be appropriate candidate materials especially
for optical and various systems.
Experiments are done by using the different amount of nitrogen and rare-earth
elements with the same rare-earth element (Er). After the sintering process, samples cuts off
the 1.2 mm thickness and samples get 80% infrared transmission between 6000 cm-1 and
3000 cm-1. Also, process parameters such as sintering temperature and cooling temperature,
affects the transparency of oxynitride glass in the visible light region.
Keywords: Oxynitride glass, Infrared, optical properties, transparency
MLZ-18
PROJE FUARI 2009
SPARK PLASMA SINTERING OF ELECTRICALLY CONDUCTIVE ZrO2 – Ti(C,N)
COMPOSITES
İbrahim Erdem İRTEM
Supervisor: Assoc. Prof. Alpagut KARA
Department Of Materıals Scıence And Engıneerıng
Faculty of Engineering and Architecture, Anadolu University
Iki Eylül Campus, 26555, Eskisehir
In the aerospace, automotive and tool field, advanced ultra hard materials are needed.
However, these advanced ceramics materials are difficult to machine with traditional methods
due to their high cost diamond and cubic boron nitride grinding tools. Consequently
alternative methods are needed such as EDM. Electrical discharge machining (EDM) is a nonmechanical contact machining technology, which allows machining of complicated parts, is
widely used for electrically conductive materials despite of their hardness. However,
engineering ceramics such as ZrO2, Al2O3 or Si3N4 cannot be machined by EDM due to
their too high electrical resistivity. In order to use the advantages of the EDM process, a
secondary electrically conductive phase, such as WC, Ti(C,N) can be added to obtain a
composite that is electrically conductive enough to allow EDM machining.
In this project, yttria-doped zirconia (YSZ) powder is used as matrix material. YSZ
powder is mixed with Ti(C,N) powder to acquire a preferable system. Ti(C,N)-YSZ powder
are sintered under pre-defined conditions by spark plasma sintering and conventional
pressureless sintering. The physical properties of sintered samples are carried out with;
Archimedes method, Scanning electron microscope (SEM), X-ray diffraction system (XRD)
and Vickers hardness indentation measurements. For electrical conductivity sample surfaces
are polished and coated for creating an electrolyte surface. Thus impedance and two point
probe techniques are employed.
MLZ-19
The experimental results revealed a strong influence of the secondary electroconductive phase to a high surface hardness and good electrical conductivity of the ZrO2based composites for EDM behavior.
MLZ-20
PROJE FUARI 2009
CHARACTERİZATİON ON NANO SCALE THİN FİLMS USİNG
X-RAY REFLECTİVİTY AND ROCKİNG CURVE TECHNİQUE
Özgün Başkan TAŞTAN
Supervisor: Assoc. Prof. Ramis Mustafa ÖKSÜZOĞLU
Department Of Materıals Scıence And Engıneerıng
Faculty of Engineering and Architecture, Anadolu University
Iki Eylül Campus, 26555, Eskisehir
Recent progress in growth techniques has made it possible to fabricate different kinds
of thin films and multilayer structures. Optimisation of the fabrication process and a physical
understanding of the samples require non-destructive methods to study the samples produced.
X-ray reflectivity (XRR) is conveniently applied for surface-interface roughness, density and
thickness determinations. XRR is nowadays used for the characterisation of coating layers for
optics and surface hardening, and different layers used in micro- and optoelectronics.
Rocking Curve (RC) technique is important for deriving the texture profile and determination
of the crystalline quality of the film.
MLZ-21
PROJE FUARI 2009
________________________________________________________________________
THE INVESTIGATION OF COLLOIDAL STABILITY OF COAl2O4
CERAMIC PIGMENT
Serhan KARABIYIKOĞLU
Supervisor: Assist. Prof. Dr. Emel ÖZEL
Department Of Materıals Scıence And Engıneerıng
Faculty of Engineering and Architecture, Anadolu University
Iki Eylül Campus, 26555, Eskisehir
Ceramic inks prepared with inorganic pigments are widely used for decoration of
ceramics. Coloured inks are prepared by dispersing of inorganic pigment in water and organic
solvent mixture. Ceramic inks, used in screen printing, are called as paste because of their
high viscosity. The stability of inks and rheological properties are affected by physical and
chemical interactions between pigment particle and solvent. To reduce decoration problems
and use new decoration techniques successfully, colloidal properties of inks and physicalchemical interactions between pigment particle and solvent should be well known. On the
other hand, there are only few related studies about these topic exist. For this reason, the
colloidal properties and stability of Co-Aluminate inorganic pigment suspension in water was
investigated. In this project, firstly, Co-aluminates blue pigments which are industrially
available were ground to about 1 µm and pigment particles dispersed in different pH values.
The zeta potential, pH/conductivity and Inductive Coupled Plasma (ICP-OES), measurement
was performed. Obtained results showed that the pigment particles dissolve in water and the
ion concentration increase with increasing time. Also, the value of the conductivity increase
with ion concentration of suspension.
Keywords: Co-Aluminate, cake, stability
MLZ-22
PROJE FUARI 2009
________________________________________________________________________
DİFFUSION BONDİNG OF MAGNESIUM AND TITANIUM FOR BİOMEDICAL
APPLICATION
Tuğçe YILDIZ
Supervisor Prof. Dr. Ali Arslan KAYA
Department Of Materıals Scıence And Engıneerıng
Faculty of Engineering and Architecture, Anadolu University
Iki Eylül Campus, 26555, Eskisehir
Degrading metal alloys are used for future biomedical applications as implant material
such as hip joint, stents and to make medical equipment. Magnesyum has good
biocompability and facilitates new bone formation and accelerates healing of bone by forming
hidroxiapatite on bone crystalline structure. Ti-6Al-4V alloy has high machanical properties
such as high strength, high corrosion and wear resistance and also good biocompability and
presently, it is used for many biomedical applications due to their excellent properties.
Therefore, this study aim is joining titanium and magnesium alloys by diffusion bonding.
Diffusion bonding requires mutual solubility and/or intermetallic compound formation
between the joining metals. Magnesium and titanium do not show either in their binary phase
diagram. However, zirconium can be used as a transition agent between magnesium and
titanium. İn this study vacuum hot pressing (VHP) technique is used for forming Tİ-Zr-Mg
structure by diffusion bonding. SEM, TEM and optic microscope are used for analysing
morfology and thickness of diffusion zone.
MLZ-23
PROJE FUARI 2009
_________________________________________________________________________
α - β SiALON/SiC COMPOSITES BY PARTIAL NITRIDATION
İsmail İŞÇİ
Supervisor: Prof. Dr. Ferhat KARA
Department Of Materıals Scıence And Engıneerıng
Faculty of Engineering and Architecture, Anadolu University
Iki Eylül Campus, 26555, Eskisehir
Silicon nitride (Si3N4) and silicon carbide (SiC) are ceramics extensively investigated,
because of their excellent mechanical properties, such as, high hardness, high strength at high
temperatures as well creep and oxidation resistance. These properties turn these ceramics,
candidates and also composite materials for structural applications such as cutting tools,
engine components and aerospace devices. For this purpose Si3N4, Al/AlN, Si, SiC, Al2O3,
Yb2O3, Sm2O3, CaCO3 powder batches were mixed by planetary milling, for 2 h, in
isopropilic alcohol. The powders were dried in the rotary evaporator. After drying, the powder
batches were sieved and compacted in two-step: (1) uniaxial pressing, under 30MPa; (2) cold
isostatic pressing under 300MPa. Sintering was done gas pressure sintering at 1990 ◦C with
an isothermal holding time of 2 h under 2,2MPa-N2. The sintered samples were characterized
by X-ray diffraction. In this study the results will be presented.
Keywords: SiALON, SiC, Composites, Nitridation
MLZ-24
PROJE FUARI 2009
INVESTIGATION OF HOT WORKED MICROALLOYED PLATE STEELS
AND EFFECTS OF THERMOMECHANICAL PROCESSES
Güneş GÜNGÖR
Supervisor: Prof. Dr. Ali Arslan KAYA
Department Of Materıals Scıence And Engıneerıng
Faculty of Engineering and Architecture, Anadolu University
Iki Eylül Campus, 26555, Eskisehir
HSLA steels (microalloyed) known as high-strength low-alloy steels provide increased
strength-to-weight ratios over conventional low-carbon steels for only a modest price
premium. Due to the fact that HSLA alloys are stronger, they can be used in thinner sections,
making them particularly attractive for transportation-equipment components where weight
reduction is important and these steels are available in all standard wrought forms such as
sheet, strip, plate, structural shapes, bar-size shapes, and special shapes. HSLA steels are lowcarbon steels with up to 1.5% Manganese, strengthened by small additions of elements, such
as Niobium, Vanadium or Titanium and sometimes by special rolling and cooling techniques.
Improved-formability HSLA steels contain additions such as Zirconium, Calcium, or rareearth elements for inclusion control. With this study, the structure, production methods and
processes of hot-worked microalloyed plate steels were investigated and how the mechanical
properties of them had changed was researched.
Keywords: Microalloy, Thermomechanic, Steel, Hsla, Hot Work Deformation
MLZ-25
PROJE FUARI 2009
________________________________________________________________________
OPTİMİZATİON OF THE PASSİVATİON HEAT - TREATEMENT APPLİED
TO B4C POWDERS TO PRODUCE B4C - AL COMPOSİTES
Umut T. SANLI
Supervisor: Doç.Dr. Gürsoy ARSLAN
Department Of Materıals Scıence And Engıneerıng
Faculty of Engineering and Architecture, Anadolu University
Iki Eylül Campus, 26555, Eskisehir
Passivation heat treatment is a process that reduces the reactivity of the powders by
changing their surface chemistry. The optimization of passivation time and temperature of
boron carbide (B4C) powders was studied in this work. The B4C powders that were
hours were used to find the optimum passivation temperature and time combination. Besides
passivated powders, as-received B4C powders were also used to investigate the effect of
passivation heat treatment on the mechanical properties of the composites. It was observed
that passivation helps reducing the amount of the reaction products namely Al3BC and
improving the mechanical properties. The phases present in the produced composites were
determined by using X-ray diffraction technique. After the passivation heat treatment, B4C
pellets were pressureless melt infiltrated under an argon gas atmosphere with an 2024 Al alloy
light-weight (< 2.65 g/cm3) B4C–Al composites. Microstructure of the produced composites
were characterised by scanning electron microscopy (SEM).
Keywords:
Passivation,
Boron
Carbide,
Ceramic
Matrix
Composites,
Al3BC.
MLZ-26
PROJE FUARI 2009
________________________________________________________________________
EFFECT OF THE PARTICLE SIZE OF NON-PLASTIC RAW MATERIALS
ON THE PYROPLASTIC DEFORMATION OF SANITARYWARE
Ömer EKER
Supervisor: Assist. Prof. Dr. Emel ÖZEL
Department Of Materıals Scıence And Engıneerıng
Faculty of Engineering and Architecture, Anadolu University
Iki Eylül Campus, 26555, Eskisehir
In sanitaryware industry, the pyroplastic deformation, commonly observed in big and
flat shape products can be modified with particle size of non-plastic raw materials, amount of
glassy phase and its viscosity. In this study, the effect of particle size of non plastic raw
materials on pyroplastic deformation was investigated. Additionally, green strength, water
absorption and shrinkage values of sanitaryware products were measured. As a result of
experimental studies, it was determined that pyroplastic deformation reduces as 5 % ratio with
decreasing particle size of non-plastic raw materials. Also the lower water absorption values
were obtained than the standard sanitaryware body formulation, especially 0 % water
absorption was obtained with grounded powder for 50 minutes.
Keywords: Sanitaryware, pyroplastic deformation, particle size distribution.
MLZ-27
PROJE FUARI 2009
_______________________________________________________________________
THE REDUCTION OF PORCELAIN TILE THICKNESS
Selda NAYİR
Assoc. Prof. Dr. Alpagut KARA
Department Of Materıals Scıence And Engıneerıng
Faculty of Engineering and Architecture, Anadolu University
Iki Eylül Campus, 26555, Eskisehir
Porcelain tile is basically made from clays, kaolin, feldspars, and quartz. Clays and
kaolins provide plasticity and dry mechanical strength and form mullite and glassy phase
during firing; feldspars are low-temperature glassy phase formers; and quartz contributes to
thermal and dimensional stability, because it is the most refractory constituent. Porcelain is
characterized by high technological properties, especially regarding water absorption,
chemical and frost resistance, bending strength and abrasion resistance. Due to its excellent
functional, mechanical and aesthetical properties it is selected as a thesis study and the main
aim of the study is that reducing the thickness of the porcelain tile without loses from its
mechanical properties. Because It is believed that the thin porcelain tile would have a definite
advantage where transportation is an important factor and in the erection of prefabricated
units. Shorter firing periods and the use of less material may be further advantages. [3] For
this purpose, four different samples that are STD, 5.5 h, 6.0 h and 14.0 h, are used. Even
though, their compositions same and contain standard porcelain raw material, their milling
times are make the differences. Besides, 90 bar, 100 bar, 110 bar, 120 bar and 130 bar
pressures are exposed to the each sample that are at 5x10 cm size and 70 g weight. The mean
of the pressure and particle size differences, to show the effect of them on the strength. After
pressing they are subjected to the three point bending test and they show different strength
values. At the result of the tests maximum strength is observed from 5.5 h sample at 130 bars.
The main problem is that loosing the strength when the tiles is heated to kiln, it can not carry
its own weight due to pyroplastic effect. By reason of, the deformation occurs more
frequently in highly vitrified pastes like porcelain tiles. The deformation highly depends on
MLZ-28
thermal work, composition and thickness of the tile and it develops as a function of
vitrification during firing.
MLZ-29
PROJE FUARI 2009
_________________________________________________________________________
INFLUENCE OF SURFACE PREPARATİON ON NANO SCALE THİN FİLM
GROWTH AND INDUSTRİAL MANUFACTURİNG
Barış ÇELTİKÇİ
Supervisior: Doç. Dr. R. Mustafa ÖKSÜZOĞLU
Department Of Materıals Scıence And Engıneerıng
Faculty of Engineering and Architecture, Anadolu University
Iki Eylül Campus, 26555, Eskisehir
In today’s thin film growth processes is seen in all applications which is used
commonly. Especially this process is used in electronic and nanotechnology applications and
will be more favorable in the future. Primary requirements on thin film growth (surface
crystal structure, surface cleaning on atomic scale and etc.) determine growth thermodynamic
and structural and functional properties. The first question on nano scale thin film growth is
that the providing of requirements is done or not. This study contains preparing of an wafer to
growth a thin film. In today’s the preparing of an wafer is done in 2 ways; physical and
chemical procedure. This study is about effects of chemical methods on wafer surfaces. In
addition the light and atomic force microscopies were used for characterizing of the wafers
MLZ-30
PROJE FUARI 2009
_________________________________________________________________________
NOVEL APPLICATION OF TEXTURED CERAMICS
Umut SAVACI
Superviser : Assoc. Prof. Dr. Ender SUVACI
Department Of Materıals Scıence And Engıneerıng
Faculty of Engineering and Architecture, Anadolu University
Iki Eylül Campus, 26555, Eskisehir
Piezoelectric ceramics are widely used in broad range of applications such as medical
imaging, microscopes, microphones and etc. Piezoelectric effect was first discovered by Curie
brother while they induce stress to quartz, it produced current. After that during the World
War huge researches were done in the piezoelectric ceramics. During researches now it is well
known lead zirconate titanate (PZT) composition was showed high piezoelectric properties.
Its’ good piezoelectric properties make PZT useful for wide range of applications. Due to the
toxicity of PZT because of lead, most researches started to investigate other lead-free
piezoelectric ceramics. BaTiO3 (BT), (K,Na)NbO3 (KNN) and (Bi,Na)TiO3 (BNT) were
candidates of lead based piezoelectric ceramics but they not have piezoelectric properties as
high as PZT. Binary compositions of these compositions investigated for better piezoelectric
properties. According to these researches binary solid solutions possess higher piezoelectric
properties but not good enough. Ternary compositions were tried and showed better
piezoelectric properties. Piezoelectric properties can be increased with some applications such
as hot pressing and many other methods. In this project first grain growth attempts were tried
for ternary composition, and in the case of success grains are oriented by using templates with
appropriate heat treatment methods.
MLZ-31
PROJE FUARI 2009
________________________________________________________________________
EFFECTS OF SEPIOLITE ADDITION ON WALL TILE BODY
Okan ANDIRIN
Danışman: Yrd. Doç. Dr. İrfan TÖRE
Department Of Materıals Scıence And Engıneerıng
Faculty of Engineering and Architecture, Anadolu University
Iki Eylül Campus, 26555, Eskisehir
In this study, raw material of sepiolite was analyzed availability for wall tile body and
variation of physical properties on body due to sepiolite ratio. Russian clay, kaolen, quartz
and Na-feldispat including mixture was prapered as main recipe. Sepiolite was added to
obtained mixture %5, %10, %15, %20 ratio weight of mixture. Ratio of Na-feldispat was
decreased due to additional ratio of sepiolite. This mixture was grinded below to 63 µm.
Granules was obtained which has %5 moisture after slurry has dried. Obtained these granule
was shaped at 5x10 cm sizes by pressing at 75 bar with hand press and was fired at 10500C,
1100 0C, 1125 0C, 1150 0C with nabertherm roller (laboratory vintage) furnace. Physical and
mechanical behaviour as firing shrinkage, firing strength, water absorbtion, density, color,
porosity of obtained ceramic materials was done characterization analyses. Physical property
of porous body strructure as wall tile was seen improve according to obtained results by
addition of sepiolite.
MLZ-32
PROJE FUARI 2009
________________________________________________________________________
PRODUCTION AND APPLICATION OF RED PHOSPHORESCENT PIGMENTS
Mehmet Tümerkan KESİM
Danışman: Prof. Dr. Bekir KARASU
Department Of Materıals Scıence And Engıneerıng
Faculty of Engineering and Architecture, Anadolu University
Iki Eylül Campus, 26555, Eskisehir
Phosphorescence is the re-emission of the absorbed radiation after a specific period of
time. It differs from luminescence in a way that emission continues after the cessation of the
excitation for several minutes to hours.
Phosphorescent pigments are utilized in many areas including military applications,
security signs, and lightening devices. Satisfactory results have been acquired in blue-green,
and yellow phosphor systems. On the other hand, red phosphorescent pigments cannot be
improved as much as blue-green, and yellow, thus cannot find many application areas.
Over 5 hours of red afterglow can be acquired in red phosphorescent systems, however
they are not chemically stable and harmful by-products are produced. For that reason, in the
scope of this thesis, production of red phosphorescent systems and their application on
traditional ceramics were investigated. Sintering regime and compositions of the systems
were changed in order to observe the afterglow time and intensity of phosphorescence.
MLZ-33
PROJE FUARI 2009
_________________________________________________________________________
ZNO ESASLI VARİSTÖR ÜRETİMİNDE YENİ BİR YAKLAŞIM
Hakan YAVAŞ
Danışman: Doç. Dr. Ender SUVACI
Malzeme Bilimi Ve Mühendisliği
Mühendislik-Mimarlık Fakültesi, Anadolu Üniversitesi
İki Eylül Kampusu, 26555, Eskişehir
Bu çalışmada, varistör uygulamalarında kullanılmak üzere hazırlanan çinko oksit ve
bizmut oksit tozlarının kolloidal sistemlerde ki kaplanma karakteristiği incelenmiştir.
Çalışmanın ilk aşamasında kolloidal kaplamada önemli olan parametreler belirlenmiş
ve bizmut oksitin su içerindeki zeta potansiyeli ölçülmüştür. Seyreltik olan hazırlanan bizmut
oksit çözeltisinin pH 1.0, 1.5, 3.0, 5.0, 6.0, 7.0, 8.3, 9.0, 10.0, 11.0 değerlerinde zeta
potansiyeli zetametre ile ölçülmüş ve izoelektrik noktası da pH 1.4 olarak bulunmuştur. Bu
aşamadan sonra kaplama yapılması planlanan pH 10 değeri için çinko oksitin su içerisindeki
zeta potansiyeli zetametre ile ölçülmüştür.
Çalışmanın ikinci aşamasında birbirinden bağımsız ve seyreltik olarak pH 10’da
hazırlanan çinko oksit ve bismut oksit çözeltileri kontrollü olarak karıştırılmıştır. Yapılmış
olan kaplamanın karakterizasyonu için SEM analizleri yapılmıştır.
MLZ-34
PROJE FUARI 2009
___________________________________________________________________________
BORTEK 11’İN METAL DÖKÜM MAÇALARINDA KULLANIMININ
İNCELENMESİ
Abdullah GÜLEÇ
Özkan KIDAK
Prof. Dr. Nuran AY
Malzeme Bilimi ve Mühendisliği
Mühendislik-Mimarlık Fakültesi, Anadolu Üniversitesi
İki Eylül Kampusu, 26555, Eskişehir
Metal döküm sanayi her gecen gün kendisini yenilemekte, en ucuz maliyetle en
kaliteli ürünü elde etme amacı ile üretim yöntemleri gözden geçirilmektedir. Üretim
yöntemlerinde ve kullanılan malzemelerde yenilikler yapılmaya çalışılmaktadır. Döküm
yöntemi, ilk çağlardan beri kullanılan bir şekillendirme yöntemidir. Döküm işlemlerinde kalıp
malzemeleri, ergitme cihazları, yardımcı malzemeler üzerinde sürekli çalışılmaktadır. Bu
çalışmada, içi boş döküm parçası üretmek için yararlanılan maçaların özelliklerine
BORTEK 11 ilavesinin etkisi incelenmiştir. Maçalar, maça kumu, bağlayıcı ve BORTEK 11
karışımının şekillendirilmesiyle hazırlanmıştır. Hazırlanan numuneler (D1, D2, D3, D4
kodları ile üretilmiştir) kalıp içine yerleştirilerek döküm yapılmıştır. Döküm işlemi sonucunda
metal parçalar temizlenmiş ve yüzeyleri incelenmiştir. Elde edilen sonuçlara göre
BORTEK 11’ in maçalarda kullanımı daha az hata oluşumuna olduğu bulunmuştur.
MLZ-35
PROJE FUARI 2009
________________________________________________________________
CHARACTERIZATION OF SiAlON-SiC COMPOSITE SYSTEM
BY USING TRANSMISSION ELECTRON MICROSCOPY
Berke ÖKSÜZ
Supervisor : Prof. Dr. Servet TURAN
Material Science and Engineering
Faculty of Engineering and Architecture, Anadolu University
İki Eylül Kampusu, 26555, Eskişehir
Silicon aluminium oxynitrides (SiAlONs) have superior mechanical and thermal
properties which are the reason of the usage in high temperature applications that are ideal
engineering materials. The mechanical properties can be adjusted over a wide range by
modifying the type and quantity of the additives. Due to having complex crystal structure of
SiAlON, their microstructure had to be investigated to improve the final product properties
and identify effective parameters on microstructure. Therefore, the parameters which are
compositional variation, grain boundary phase, microstructure and secondary phase addition
had to be investigated. In this study, SiAlON- SiC (Silicon carbide) and SiAlON- ZrO2
(Zirconia) composite system were utilized for characterization. Samples were prepared by
Cross Section Polisher (CP) for Scanning Electron Microscope (SEM). Samples were into
electron transparent by cutting, grinding, ultrasonic disc cutter, parallel polishing and ionbeam processes for Transmission Electron Microscope (TEM) investigations. And then, these
samples were characterized by utilizing Energy Filtering (EFTEM), parallel electron energy
loss spectrometer (PEELS), High angle Annular Dark Field (HAADF) Scanning Transmission
Electron Microscope (STEM) detector and Energy-Dispersive X-Ray (EDX) spectrometer
attached to TEM.
Keywords: SiAlON, SiC, ZrO2, characterization, TEM
MLZ-36
PROJE FUARI 2009
___________________________________________________________________________
MECHANICAL PROPERTIES OF SiC-B4C-Al COMPOSITES
Fatma KARANFİL
Supervisor : Assist. Prof. Dr. Gürsoy ARSLAN
Department Of Materıals Scıence And Engıneerıng
Faculty of Engineering and Architecture, Anadolu University
Iki Eylül Campus, 26555, Eskisehir
B4C-Al composites are the most favorable material to use in the ballistic applications.
SiC is the ceramic material which are similar mechanical properties with B4C and cheaper
than B4C. In this thesis, it was aimed to investigate mechanical behaviour of SiC-B4C-Al
ceramic-metal composites to use multiple impact resistance armour materials. The passivated
B4C and SiC were mixed and Al was infiltrated at 973C and 1h via pressureless infiltration
method. Passivation condition of B4C was 1400C and 2h. The microstructure of the
composites were investigated using a scanning electron microscope (SEM) and the phases
quantity were determined by using X-ray diffraction (XRD) analysis. Vicker microhardness
and compression test will be done to investigate mechanical properties of composites. The
result of the XRD was the reaction product of Al4C3 that affect the mechanical properties
negatively was not exist in the system.
Keywords: SiC-B4C-Al Composites, Mechanical Properties, Balistic Application.
MLZ-37
PROJE FUARI 2009
________________________________________________________________
PORSELEN KARO SIRI UYGULAMALARI İÇİN OKSİNİTRÜR CAMLAR
Suna AVCIOĞLU
Danışman: Prof. Dr. Hasan MANDAL
Malzeme Bilimi ve Mühendisliği
Mühendislik-Mimarlık Fakültesi, Anadolu Üniversitesi
İki Eylül Kampusu, 26555, Eskişehir
Bu çalışmanın amacı, genel kullanıma açık alanlarda tercih edilen porselen karoların
aşınma
direncini
arttırmak
için
porselen
karo
sırlarında
oksinitrür
camların
kullanılabilirliğinin araştırılmasıdır.
İlk olarak oksinitrür camların potansiyeli hakkında fikir sahibi olmak amacı ile
literatür incelemesi yürütülmüştür. Ardından oksinitrür camların sır olarak uygulanabilirliği
ve porselen karo pişirim rejimi ile oksinitrür camların sentezlenme davranışları
ilişkilendirilmeye çalışılmış, aralarında sağlanabilecek uyum araştırılmıştır. Daha sonra sırlı
porselen karoların yüzey özelliklerini (örneğin; aşınmaya karşı direnç ve sertlik) etkileyen
faktörler ve iyileştirilmeleri için kullanılan genel yöntemler araştırılmıştır.
Bu çalışmada üç farklı ticari frit ile çalışılmıştır. Kompozisyonlarına farklı oranlarda
çeşitli azot kaynağı hammaddeler eklenerek porselen karo üretim koşullarında cam ağı
içerisine girmesi amaçlanmış, etkileri gözlenmiştir. Her sistem için benzer öğütme ve pişirim
koşulları sağlanmıştır. Tüm kompozisyonlar bir saat jet değirmende öğütülmüş ve öğütme
işleminin son 5 dakikasında nitrojen içerikli hammadde kompozisyona dahil edilmiştir. Elde
edilen sırlar karo yüzeyine uygulanıp kurutulduktan sonra 20 ºC/dk hızla 1200ºC’de hızlı
pişirim fırınında pişirilmiştir. Numunelerin yüzeyinde pişirim esnasında sistemdeki nitrojen
kaynağının oksitlenmesi nedeniyle gaz çıkışı problemi meydana gelmiş, kabarma ve kaynama
gözlenmiştir. Ancak meydana gelen yüzey hatalarının kompozisyon farklılıklarına göre
değişim gösterdiği söylenebilmektedir
MLZ-38
PROJE FUARI 2009
________________________________________________________________
BOR NİTRÜR (BN) OKSİDASYONU
Cem KARAKÖYLÜ
Danışman: Yrd. Doç. Dr. İrfan TÖRE
Malzeme Bilimi ve Mühendisliği Bölümü
Mühendislik-Mimarlık Fakültesi, Anadolu Üniversitesi
İki Eylül Kampusu, 26555, Eskişehir
Bu çalışmada bor nitrür (BN) tozunun çeşitli sıcaklık değerlerindeki oksidasyon
davranışı incelenmiştir. Oksidasyon davranışları uygulanan sıcaklık değerlerinde kuru hava
atmosferinde gerçekleştirilmiş olup, yapılan deneysel çalışmalarda bor nitrür (BN) tozunun
oksidasyon davranışları sırasıyla 500 oC, 600 oC, 700 oC, 800 oC, 900 oC, 1000 oC, 1100 oC
sıcaklıklarında incelenmiş ve uygulanan her bir sıcaklık değerinden sonra bor nitrür tozunun
oksidasyon davranışının sıcaklık değişimlerine göre gösterdiği değişiklikler hassas tartımlar
ve XRD analizleriyle desteklenilmeye çalışılmıştır.
MLZ-39
PROJE FUARI 2009
________________________________________________________________
HEGZAGONAL BOR NİTRÜRÜN YAŞ ORTAMDAKİ ÖGÜTME
PARAMETRELERİNİN İNCELENMESİ
Ahmet Serter KARABIYIK
Danışman: Prof. Dr. Nuran AY
Malzeme Bilimi ve Mühendisliği
Mühendislik-Mimarlık Fakültesi, Anadolu Üniversitesi
İki Eylül Kampusu, 26555, Eskişehir
Üretilen parçacıkların en büyük boyutunun yaklaşık 5mm’den daha az olduğu hallerdeki
yüzey büyültme işlemine öğütme adı verilir. Öğütme işlemi, öğütülecek maddenin özelliklerine ve
kullanılan değirmene bağlı olarak kuru ve yaş olarak yapılmaktadır. Öğütmenin su, alkol ve heptan
gibi bir sıvı içinde yapılması hem öğütme süresini kısaltır, hem de ince tozlar üretilmesini sağlar. Bir
öğütücünün verimliliğini öğütme ortamının çarpışma hızı ve öğütücü içindeki malzemenin
hareketliliği belirler. Tüm seramik ürünler tozlardan elde edilmekte ve ürünün bazı özellikleri
(ör. mukavemet, kırılma tokluğu ve ısıl iletkenlik) tozun tane boyutu ve tane boyut dağılımı
ile ilgilidir. Üretilecek ürünün özelliklerinin istenilen derecede olması için tane boyutunun ve
tane boyut dağılımının mümkün olduğunca optimum değerlerde olmalıdır.
Bu çalışmada faktöriyel deney tasarımı ile 300 µm üstünde ki h-BN numunesinin
bilyalı değirmende öğütülmesi sonucunda, tane boyutunun uygulanan öğütme ortamına (su,
alkol) ve dönme hızına göre nasıl değiştiği incelenmiştir. Numunelerin XRD, SEM, tane
boyut analizi yapılmıştır.
Anahtar kelimeler: h-Bn, yaş öğütme, bilyalı değirmen,
MLZ-40