فرع الفيزياء التطبيقية

Study Some physical properties and color stability of manufactured dental ceramics

By:Saja Moussa Jawad, Supervised By: Prof. Dr. Enas Muhi Hadi

year: 2024

Abstract

Color is among the most important factors that affect the aesthetic appearance of artificial teeth were prepared by using 3% yttria-stabilized tetragonal zirconia polycrystalline (3%Y-TZP) in

four zirconia systems (Z-Y, Z-T, Z-T-A, Z-T-G), Titania  (TiO2) nano and micro was added in

weight ratios (2,4,15,20,25)  %. Alumina  (Al2O3) was added in weight ratios (6.5 and 12)  %.

and lithium disilicate glass (Li2Si2O5) was added in weight ratios (12.5 and 25)  %. The

specimens were formed using a uniaxial hydraulic press at a pressure of 3 tons and sintered for

(2 hrs.) at 1200 ◦C, 1400 ◦C, and 1500 ◦C, several properties were examined physical,

mechanical, and structural properties  Also, thermal conductivity, and both surface roughness

and microhardness all were studied before and after immersion in artificial saliva and tea.

Where the specimens were immersed in artificial saliva for (24 hrs) for three months, and then

the specimens were immersed in tea for half an hour daily for three months. The x-ray

diffraction (XRD) results show the tetragonal phase as the main phase with a small percentage

of monoclinic phase due to 3% yttria addition and tetragonal zirconia has excellent mechanical

properties such as fracture toughness. and scanning electron microscope (SEM) results indicate

homogeneous grain distribution and low apparent porosity. At 1500°C, the addition of 25%

nano titania decreased apparent porosity from 0.2 to 0.05, 16% titania-alumina decreased it

from 0.2 to 0.04, and 29% titania-glass decreased it from 0.2 to 0.03. Water absorption

decreased with lower apparent porosity. Apparent density increased with nano titania: 25%

from 4.06 g/cm3 to 4.95 g/cm3, 16% of titania-alumina from 4.06 g/cm3 to 5 g/cm3, and 29% of

titania-glass increased from 4.06 g/cm3 to 5.45 g/cm3. microhardness increased at an additional

ratio of 25% nano TiO2 from (450 MPa) to (1100 MPa), at 16% (titania-alumina) increased

from (450 MPa) to (1200 MPa) and at 29 % (titania-glass) increased from (450 MP) to (1250

MPa) so the best value of microhardness was obtained at a 29% titania-glass and diametrical

strength increased to more than (75 MPa) at a ratio of 25% of nano TiO2. Specimens immersed

in artificial saliva and tea for 3 months showed no changes in surface roughness and

microhardness. Vita shade (3D-Master) results indicated that the color values of L, R, and M

closely matched those of natural teeth. Notably, the mixture containing 29% Z-T-G exhibited

excellent color stability, making it one of the top-performing mixtures in terms of maintaining

color integrity.

Investigation of Alumina Filled Zirconia/Yttria for Dental Ceramic Applications

By: Areej Talal Ayyash, Supervised By: Prof. Dr. Enas Muhi Hadi

year: 2024

Abstract

Natural teeth are exposed to diseases and accidents that lead to tooth damage, so

replace natural teeth with artificial teeth that suit the oral environment.

This research studies the possibility of toughing and improving the mechanical, and

physical properties of the zirconia systems through added alumina to the zirconia for

the teeth industry. Specimens were prepared from 3%mol(Y2O3) yttria-stabilized

tetragonal zirconia polycrystals (Y-TZP) with added alumina (Al2O3) with particle

size (50nm Nano, 50μm micro) at different Wight ratios (2, 4, 15, 20, and 25) %. The

specimens were formed by a uniaxial and isostatic pressing hydraulic press (3) Ton

and sintering at 1570 ºC for 2 hrs. The dental specimen’s physical (Apparent porosity,

Apparent density, Water apportions, surface roughness) mechanical properties

(Vickers micro hardness, Diametrical strength, and wear rate), and weight loss were

investigated. In X-ray diffraction, it appears the main phase is tetragonal as a result of

the addition of yttria to stop phase transitions in zirconia. It showed that the specimens

consisted of two materials: tetra crystalline zirconia (Y-TZP) stabilized with yttria and

alumina after sintering at 1570 ⁰C. The specimens showed in Scanning Electron

Microscope (SEM) that the distribution of materials is homogeneous in the specimens,

the absence of pores and dense materials, and the appearance of the tetragonal crystals

of zirconia. The results showed the physical properties of the specimens, decreased

the porosity appeared close to zero (0.09) %, and the apparent density increased to

(4.95) mg/cm3 when 25% Nano-alumina was added to (Y-TZP). They also showed an

increase in mechanical properties such as hardness (1241) Mpa and diametrical

strength when 25% Nano-alumina was added to (Y-TZP) and appeared low wear rate

when a weight of (50,100) N for half an hour. The specimens of zirconia systems were

immersed in artificial saliva for 24 hrs and immersed in the acid solution (acetic acid

and citric acid) for half an hour per day for three months. After immersion, surface

roughness, hardness, weight loss, and wear rate were tested. The results showed no

change in surface roughness and hardness of the specimens. The results also showed

no increase in the wear rate and no weight loss of the zirconia system specimens. The

specimens prepared from alumina-toughened zirconia have good mechanical

properties and are suitable for the dental industry in the oral environment.

The Effect of Natural Hybrid Reinforcement Unsaturated Polyester on Properties

By: Wissam Nubras Adnan, Supervised By: Assist. Prof. Dr. Zaynab Naif Rasheed & Assist. Prof. Dr.Qahtan Adnan

year: 2023

Abstract

The aim of this study is to develop the specifications of unsaturated polyester (UPE)

resin by adding natural fibers and natural particles as reinforcing material. These natural

filler materials are chosen to be sisal fiber (SF) as natural fiber and pomegranate shell

particle (PSP) and coconut shell particle (CSP) as natural particles. Both types used were

treated with sodium hydroxide (NaOH) to increase the connection with the UPE before

using it as a reinforced material.

In this study, the selected weight fractions (5, 10, 15, and 20 wt.%) for the natural

particles and for natural fiber were selected to be (2%) in all cases. Hence, the effects of

variables (weight fracture) were investigated on the mechanical properties (impact

strength, wear rate, hardness, flexural strength, flexural modulus, and surface roughness)

and the physical properties (density, water absorption, and thermal conductivity). In

addition, miscibility and morphology tests were also studied.

Results showed compared with pure UPE, a clear improvement in the mechanical

properties of the UPE reinforced with sisal fibers. When (5wt%) CSP was added to the

fiber-particle reinforced polyester, the flexural modulus increased (22%), but decreased

(33%), when PSP was added at the same ratio. The flexural strength increases when the

ratio of CSP particles rises but reduces with a rising PSP ratio. It’s interesting to note that

the impact strength value increased (7%) when adding (5 wt.%) CSP and (23% when

adding PSP in the same ratio, while it decreased at higher ratios. The maximum shear

increased (16%) with reinforced PSP (5 wt.%) and (45%) with reinforced CSP (20 wt.%).

The surface roughness value continuously rises as the additive ratio increases. The

hardness increases when polyester is reinforced with all filler types (CSP and PSP), while

increasing by 16 percent with PSP and by 21 percent with CSP. Wear rate decreases

when it is reinforced with CSP and PSP; also, the highest density was at (15, 20) wt.% of

PE/sisal/CSP hybrid composite when reinforced with all additives added in varying

amounts. Water absorption decreases when SF and CSP are added but rises when PSP is

added, reaching a maximum of 15%. Thermal conductivity increased by 4% when

reinforced with sisal fiber, 24% when PSP (20w.%) was added, and 68% when CSP was

added at the same ratio. Finally, with PE reinforced with (SF, PSP, and CSP), the specific

heat increases, and the maximum value is set at 20%. For miscibility and morphological

tests, the results of Fourier transform infrared spectroscopy (FTIR) on sisal fiber before

and after treatments showed that the bonding process had been accelerated because the

band intensity in the treated fibers was less intense than that in the untreated fibers. As

for the results of the scanning electron microscope test (SEM), they were carried out for

the polyester matrix, where impact test samples with percentages of 5% and 20% were

used for each of the UPE with PSP and the UPE with CSP. When reinforced with PSP,

the particles’ distribution became somewhat unbound in some areas and had a heterogeneous structure. When the composite was reinforced with CSP, it had a fairly

uniform distribution of submerged particles within the polyester resin and a strong

bonding between the particles, the resin, and the fibers. Finally theses samples can use in

many application such as, Automobiles, airplanes, furnishings, construction and other

structural application.

Preparing Aluminum Metal Matrix Composite Reinforced with Hybrid Particles

By: Aya Saad Abdul- AL Rahman, Supervised By: Dr. Mofeed A. Jaleel & Assist. Prof Dr. Awfa abdul-Rassol

year: 2023

Abstract

Aluminum metal matrix composites (AMMCs) are an imported type in

material science, and their applications have been increasingly applied during the

past years, especially in wear resistant materials, it is an essential factor to consider

as it directly affects the lifespan and performance of the brake pad. This research has

found that the improvements in the wear rate and mechanical properties (hardness

and compressive strength) of aluminum matrix composites can be made of Al/SiCn

composites and Al/SiCn/Grµ hybrid composite by using the powder metallurgy

technique. This work deals with, Al/SiCn composite includes the additional nano

silicon carbide particles SiCn with different volume fraction (2, 4, 6, 8,10 to pure Al)

while for Al/SiCn/Grµ hybrid composites a further addition was (1,3,5) by volume

friction of micro-graphite particles (Grµ) with different particle size at 3% Gr. The

starting powder was wet (magnetic stirrer, ultrasonic) and dry (heating 80 °C for one

hour and oven 80 °C -2h) in oven for mixing the best uniform distribution was

achieved by this method.

Then compacted via cold pressed at 180 MPa for 3 min and sintered for 2

hours at 620 °C on AMCS, mechanical and tribological properties and intermetallic

composite examination via XRD diffraction were studied. Also, Optical and SEM

were used to investigate the morphology of mixed powders and some nanocomposite

samples. Results of optical microscopy images of mixed powders for the Al matrix

and hybrid nanopowders (SiC + Gr) indicate good mixing between the different

micro and nanopowders and homogenous distribution of nanopowders in the Al

matrix, SEM micrographs of the fracture surface of the hybrid composite showed

the plastic deformation of hard ceramic(SiC) with high porosity of solid

lubricant(Gr). The X-Ray results showed no intermediate phase appeared between

SiC, Gr and Al, the SiC, Gr intensity increased as the volume fraction of them

increased.

The physical properties of the hybrid composite, including, density and

porosity of sintered specimens were also characterized by Archimedes technique. As an increase via porosity percent and decrease in density had found as the volume

fraction of SiC, Gr increased.

Mechanical properties of the hybrid composite showed great improvement

compared to pure Al, the highest values for microhardness and compressive strength

were achieved by Al/6% SiC/3% Gr at 75µm particle size of Gr (220 HV) and Al/6

% SiC (154.6 MPa), respectively.

Tribological properties assessed the composites resistance to wear and its

frictional behavior under sliding contact, the results were evaluated to identify

favorable volume fraction and particle size combinations that exhibited reduced

wear and coefficient friction rate, the best-recorded result as (0.242) at Al/4%

SiC/1% Gr, (0.105) at Al/5%Gr for wear and coefficient friction.

Improvement of Mechanical Properties of 3D Printed Polymers

By: Ghaithe Yousif Dakhel,  Supervised By: Assist. Prof. Dr. Rana M. Salih & Prof. Dr. Awham M. Hameed

year: 2022

Abstract

In this work aims to enhance the mechanical properties (compression

strength, flexural strength, impact strength tensile strength and hardness) of

Polylactic Acid (PLA), a 3D printed Polymer material. The fused deposition

modelling (FDM) technique was used to produce the 3D printed samples. The

polymer filaments were manufactured into 3D prints using locally-made 3D

printer. And the specimens were designed by a software that transfers design

patterns into the moving printer head with a nozzle that pushes the melted

polymer into the final shape. Three specimens of each type have been tested

with a selected infill ratios (30, 50, and 70%) and infill pattern (line, gyroud,

and tri-hexagon).

The results showed that the 70 percent infill ratio with linear pattern had

the highest compressive strength, in case of the compression test, the test was

done using general-purpose (EN772-1) manual compression testing machine for

blocks, cubes and cylinders in accordance with the standard specification

(ASTM D695), Tri-hexagon infill pattern with 70% infill ratio proved to have

the highest values of Flexural strength in the case of Flexural Test, which

performed using 3-point bending method according to (ASTM D-790). By

universal testing machine (UTM) from (ADMET)/USA. The flexural strength

of the samples was calculated and given from the testing machine instantly

when the test was finished, the impact strength of samples was determined by

using an impact taster according to ISO-179 standards. The impact strength of

the specimens was calculated in unit kJ/m2

. Tri-hexagon infill pattern with 70%

infill ratio proved to have the highest values of Impact strength in the case ofImpact Test. The tension test was accomplished on samples with standard

dimensions according to (ASTM D-638) , by using tensile machine made in UK

from AZoMaterials (Testometric AT-S and CT- S models). A crosshead speed

of (5 mm/min) was employed as the test speed, Linear infill pattern with 70%

infill ratio proved to have the highest values of both Young’s modulus and

tensile strength in the case of Tensile Test. Hardness (Shore D) test shows that

the maximum hardness value was found at the base side of the specimens and

the result of hardness test for all surfaces of the sample were in the hardness

standard properties range of (PLA) which is between (67 – 85).

The results also showed that the 30 percent infill ratio with Gyroud

pattern had the highest compressive strength, Tri-hexagon infill pattern with

30% infill ratio proved to have the highest values of Flexural strength in the

case of Flexural Test, The same pattern and infill ratio also had the highest

values of Impact strength in the case of Impact Test, Linear infill pattern with

30% infill ratio proved to have the highest values of both Young’s modulus and

tensile strength in the case of Tensile Test.

In case of 50 percent infill ratio the Line pattern had the highest

compressive strength, Tri-hexagon infill pattern with 50% infill ratio proved to

have the highest values of Flexural strength in the case of Flexural Test, and the

same pattern and infill ratio also had the highest values of Impact strength in the

case of Impact Test, Gyroud infill pattern with 50% infill ratio proved to have

the highest values of Young’s modulus, the Line pattern had the highest tensile

strength in the case of Tensile Test.

Preparation and characterization of copper oxide nanostructure by CBD method for optoelectronic applications

By: Zainab Mohammed Sadiq, Supervised By: Dr. Mustafa A. Hassan & Dr. Khaleel I. Hassoon

year: 2022

Abstract

Copper Oxide thin films with nano rod-like structures have been prepared by

using chemical bath deposition (CBD) method. Both the effect of the

annealing temperature (400 and 500 ⁰C) and concentration (0.050, 0,075 and

0.1 M) on the prepared samples were studied. Some tests were carried out

for the structural properties (XRD, FESEM, and AFM), optical properties

(UV-Visible and Reflectance), and electrical properties (DC-conductivity

and Seebeck effect).

The results of the X-ray diffraction test revealed that the films have the most

obvious peak patterns at 35.60 and 38.72, which belong to the two

orientations (002) and (111), respectively, and they have a monoclinic

crystal phase. It was found that before heat treatment, the films are weakly

crystallized. After annealing, the films have improved crystalline quality,

and the CuO thin film posses little dependence on precursor concentration.

FE-SEM measurement indicated that the as-deposited film showed irregular

shapes. However, after annealing, the morphology is changed to nano-rod

shapes. EDS examination confirmed the presence of Cu and O elements in

the films, with no peaks indicating the presence of any impurities was

observed.

The results of the optical properties showed that the prepared films at 0.1 M

have a high absorption coefficient of about 104 cm-1

and an energy gap

ranging from 1.55 to 2.2 eV. Consequently, CuO is a good candidate for

solar cell applications.

Nano Metal Oxide Effect on Attapulgite for Petroleum Wells

By: Worood Ayad Abd-Alameer Salman, Supervised By: Prof. Aqeel Shaker Al-Adili & Asst. Prof. Dr.Sadeer Mowafaq Majeed

year: 2022

Abstract

For the successful drilling for oil and gas, the drilling fluids are essential

materials. In drilling applications, the most commonly used drilling fluids are

water-based fluids. They are the first fluids of choice for drilling applications

because of their cost-effective, environmentally friendly and non-hazardous

nature and locally sourced materials. The major problem is that the gel strength

of the drilling fluids produced using local substitutes is too low and the fluid loss

is too high. As a result, drilling processes are not sutitable for drilling fluids

affected.

Drilling operations will be successful when suitable drilling fluids are used to

minimize or control hole problems. Numerous studies have been carried out to

improve the drilling fluids used in drilling oil wells. Recently, nanotechnology

applications have shown a positive impact on drilling fluid technology. The

objective of this study is to formulate locally drilling fluids supported

nanomaterials to improve the filtration and rheological properties related to

these fluids.

The attapulgite claystone of Bahar Al-Najaf region is known with (43.4 and 13.9

wt %) of calcite and quartz minerals, respectively. This work is devoted to

develop the attapulgite clay which exist at Bahar Al-Najaf region (studying area)

to be suitable for oil wells drilling mud. The target of this work is matding the

standarels of attapulgite clays of Bahar Al-Najaf with those related to the

American Petroleum Institute (API).

In order to reach this target; the undesirable material (calcite and quartz particles

with diameter greater than 75 µm) should be removed. In addition developing

the dispersion of attapulgite rods, should be obtained.

In this work, Iraqi attapulgite clay was processed with acetic acid with

concentration of (1.138) M, and wet sieving condition was performed with

speed 1800 rpm for 20 min and 38 µm mesh size to make it suitable in oil wells drilling mud preparation, MgO/TiO2 Nano-composite was prepared by sol-gel

method and liquid phase precipitation method at different weights of (0.02, 0.05,

0.08) g.

XRD and FE-SEM tests were utilized for mineralogical and morphological

identification respectively and Ofite viscometer. Ofite Low-Pressure Filter Press

were used to measure the rheological and filtration properties of the produced

attapulgite from the investigated processes before and after addition of different

Nanoparticles. For the wet sieving process, the results showed that the stirring

speed and stirring time had great effect on raising the yield of the process.

The results of upgrading process with acid treatment for separated attapulgite

using the weak acid (acetic acid) showed promising outcome to remove whole

calcite mineral without causing any damage to attapulgite morphology.

Therefore, upgrading attapulgite clay with acetic acid gave best rheological

properties.

The results, after addition with different nanomaterials, assured that:

Magnesium oxide showed a great contribution to apparent viscosity and plastic

viscosity by 16% of attapulgite aqueous suspensions.

Titanium dioxide nano particles (TiO2 NPs) showed a good reduction percentage

(-4%) in filtrate volume when added to Attapulgite drilling mud, It was noticed

that the material (TiO2 NPs) improved the viscosity rate by 2% slightly.

Both nanomaterials gave little improvement in the density of drilling mud

(MgO, TiO2) nanoparticles in the rate of (2 and 2.1) % respectively. Based on

the previous results, the concentrations of nanomaterials that gave the best

improvement for filtration properties and viscosity were selected to be (0.05,

0.08) g.

Study the Behavior of Epoxy-Glass Waste Composite in Aggressive Media

By: Hadeel Ibrahim Kadhim, Supervised By: Asst. Prof. Dr. Awham M. Hameed & Asst. Prof.Dr. Besma M. Fahad

year: 2022

Abstract

The world is evolving toward extending the life of commodities and decreasing

waste by recycling. The purpose of this study is to improve resistance of epoxy against

the corrosive conditions by reinforcing it with available chemically resist materials

have low cost. This study suggests using the glass waste (G.W) to prepare polymer

matrix composites (PMCs) for different applications. Four sets of samples were

prepared of (50%) weight fraction, two sets of samples were made and treated at

ambient temperature, while others were treated at 50°C for two hours. Each set

included either reinforced or unreinforced epoxy. These samples were immersed in

different media (Tap Water, (0.5N) NaOH, (0.5N)HCl, Kerosene and Benzene).To find

out the resistance of the epoxy after reinforcing, some physical and mechanical tests

were carried out, including Optical Microscope, Density, Absorption, Hardness,

Compressive strength, Elasticity Modulus, Flexural and Impact Strength.

After seven months of immersion, physical and mechanical properties

remained unchanged for the composites, in contrast to pure epoxy which all its

properties had decreased, that clarified by microscopic images. Composites reinforced

by glass particles show an increase in physical and mechanical properties, when

compared to elegant epoxy resin alone and remains constant during the immersion

period at ambient temperature as well as at 50°C. The increase in the ratio of Vickers

hardness, Compressing strength and Elasticity Modulus were (67%, 14% and 62%)

respectively at room temperature, while Flexural and Impact strength were (44MPa)

and (8 kJ/m2

) respectively. In addition, the results showed an improvement in those

properties of the reinforced and unreinforced samples cured at 50°C. The solutions that

had the highest effect on pure epoxy were (HCl and water). This indicates that epoxy

acquire resistance after reinforcing with glass waste. It showed good resistance to

absorbance of solutions. This encourages glass waste recycling by producing

composites with low cost, and with high resistance to corrosive media that may be used

for a variety of applications.

Preparation and Study of Some Properties for Polymer Reinforced with Metallic Wastes

By: Farah Sadeq Ali, Supervised By: Prof. Dr. Awham M. Hameed & Assist. Prof. Dr. Rana M. Salih

year: 2022

abstract

In recent years, waste has spread in its different forms, metallic, plastic and

glass, so this research aims to invest and recycle metallic waste to manufacture new

composite material and study its characteristics.

This study involves the preparation of two polymer matrix composites which

are inexpensive, environmentally friendly, and utilitarian by the hand lay-up process.

Unsaturated polyester resin (UPR) was used as a matrix reinforced with metallic wastes

such as Al flakes in one composite and Fe filings in the other composite with different

weight fractions (0, 10, 30, 40 and 50) % . All samples were subjected to mechanical and

physical tests such as (bending, tensile, hardness, flexural, shear, impact, wear, friction

and density tests), and the scanning electron microscope (SEM) of fractured samples’

surfaces was conducted.

It was found that 10 % wt. of (UPR-Al flakes) is the best reinforcement ratio

in tensile, hardness, flexural and shear strength, and Young’s modulus tests. (SEM)

micrographs showed there is a good distribution at 10 % of Al flakes inside the matrix,

and the polyester covers the fillers completely. This denotes an excellent interstitial

adhesion between them. While the 50 % wt. of reinforcement was optimum ratio in the

impact strength, wear rate, and density where the percentage of increasing in the impact

strength and density was approximately 32 %, and 24 %, respectively and the wear rate

decreased by 92 %.

As for the (UPR-Fe filings), it was found that the addition of iron filings

increased Young’s modulus by 35 %, and the density by 79 % at 50 % wt. The optimum

value for impact strength and hardness observed at 30 % wt. with increasing 43% and 8

% respectively, while when 10 % wt. of Fe filings was added, the tensile strength was

increased with 8 %, and the wear rate was decreased with 96 %.

Preparation and Characterization of Iron Sulfide thin films for Optoelectronic applications

By: Mustafa Majid Ibrahim, Supervised By: Dr. Mustafa A. Hassan & Dr. Khaleel I. Hassoon

year: 2021

abstract

In this work, iron sulfide thin films were prepared by the tilt chemical spray

pyrolysis. Two different salts were used (iron nitrate, iron chloride), (FeCl3,

Fe(NO3) 3.9H2O), and three different proportions of thiourea (NH2)2C.S was

used (1.25M, 1M, 0.75M) to obtain sulfur, and two different temperatures

(200°C, 350°C) were used. The prepared thin films by thiourea (1M) were

annealed at temperature (400°C) in the presence of sulfur and argon gas. The

structural, optical, and electrical properties were studied. The structural

properties analysis showed that the thin films prepared with thiourea

concentration (1.25M, 0.75M) are amorphous structure and irregularly shaped

films. The thin films prepared with thiourea concentration (1M) are amorphous

structures in the thin film prepared from iron nitrate salt, the thin film prepared

from iron chloride salt contains two phases (pyrite, marcasite), the thin films

also have regular shapes nanostructured. The annealed thin films are

polycrystalline for the thin film prepared at 350°C for the thin film prepared at

200°C, the XRD analysis showed the start of the crystallization process. The

study of the optical properties, by calculating the energy gap of the permissible

indirect transmission, and the energy gap values were between (1.53-1.26 eV),

and the Seebeck examination showed that the films prepared were p-type, that

the prepared films have an absorption coefficient between (2 x 105cm-1-1.1). x105cm-1). As the Seebeck analysis showed that the prepared films are p-type,

that the prepared films have an absorption coefficient between (2x105cm-1-1.1x105cm-1), The electrical properties were studied and it was found that the

conductivity at the range (0.2(.cm)-1- 3.1(.cm)-1). The thin films were used in

the application of the DSSCs as the counter electrode and it was found that the

highest efficiency was (6.3%) for the films prepared with thiourea

concentration (1.25M).

Preparation Refractory Mortar of Iraqi raw Materials to Line Furnaces

By: Faten Hassan Gatem, Supervised By: Prof. Dr. Enas Muhi Hadi

year: 2021

abstract

A low-cost refractory mortar was prepared from medium alumina

refractory brick grog and local Iraqi raw materials (Kaolin , Bentonite ).

That can be used in building and coating furnaces walls works at high

temperatures.

The medium alumina refractory bricks were crushed, grinned then

saving into three different sizes (coarse – medium – fine) then mixed as

(50% coarse, 30% medium and 20% fine. ). two types of mortar (Kaolin –

Mortar) (Bentonite – Mortar) were prepared by adding clays in different

weight percentages (10, 15, 20, 30, 40)%.

The specimens were prepared by hand-forming method, then dried at

room temperature for (24) hrs, then firing at (1150) °C, physical

mechanical, thermal and microscopic tests were carved out to study

the ability of refractory mortar in thermal application.

The results shows that the apparent porosity decreases with the addition

of clays (Kaolin-Bentonite) and the highest apparent porosity were

(29.53% for K-mortar) and (27.785% for B-mortar) at 10% clay, the

water absorption decreases with the increase in the percentage of clays

(Kaolin-Bentonite) addition and that the highest water absorption ratio

were (25.52% for B-mortar) and (24.6% for K-mortar) at 10% clay, in

contrast to the apparent density increases with an increase in

clays(Kaolin-Bentonite) percentage (2.4g/cm3

for K-mortar) (2.6g/cm3

for B -mortar) at 40%clay. As for the specific heat capacity, it decreases

with the increase in the percentage of clays (Kaolin- Bentonite) addition.

the highest specific heat capacity were (900.15J/kg .k for K-mortar) and

(877.26J/kg .k for B-mortar) at 10% clay, the thermal expansion

increases with an increase in the percentage of clays (Kaolin-Bentonite)

were (3.65 1/°C for K-mortar) and (5.71 1/°C for B-mortar) at

40%clay, It was noticed that Thermal conductivity increases with

increasing of clays (Kaolin- Bentonite) addition and the highest thermal

conductivity were (10.23 w/m.k for K-mortar) and (12.39w/m.k for Bmortar) at 40% clay. The bond strength increases with increasing clays (Kaolin-Bentonite)

addition and the highest binding strength were (4Mpa for K-mortar) and

(3.8Mpa for B-mortar) is at 40%clay.

X-ray diffraction shows that the two types of refractory mortar (Kaolin

– Mortar) and (Bentonite – Mortar) consist of two main phases, mullite

and cristobalite, after firing at (1150) ℃.

Preparation and Characterization of Micro and Nano Barium Titanate with Nano Silica Composites

By: Ghadeer Sadiq Jassim Dawood, Supervised By: Asst. Prof. Dr. Mojahid Mohammed Najim & Asst. Prof. Dr. Wafaa Mahdi Salih

year: 2021

abstract

The Pure homogeneous Barium Titanate with formula (BaTiO3) was

prepared by Solid State reaction method, from Barium Carbonate (BaCO3) and

Titanium Oxide (TiO2) as raw materials having micro size by mixing of molar

ratio ]1:1[, powders (disk shape ceramic samples) were calcined at (900, 1000,

1100, 1200, and 1350)◦

1. The resulting powders were characterized using XRD,

Scanning electron microscopy was performed to verify the preferred method in

producing fine Barium Titanate powder. Then, the X-ray diffraction patterns

were compared for both the micro and nano powder, with different sintering

temperatures. The homogeneous fine nano and micro powders of Barium

Titanate were doped with silicon dioxide with different ratios (1, 1.5, 2, and 2.5)

1. %, each ratio separately. Then sintering at different temperatures (1000 –

1300) ◦

C with disk shape ceramics samples was performed.

According to X-ray diffraction, the pattern for this method manifested all

the peaks of Barium Titanate powder shown well fitted to the positions of the

peaks of the standard tetragonal phase and with preferred crystalline size for the

powder calcined.

For the physical properties of the pure and doped samples, it was

observed that the addition of SiO2 effects on the physical properties, water

absorption ability decreases with the decrease in the apparent porosity when

sintering temperature increases, and that the volumetric shrinkage decreases

with the bulk density decrease when the ratio of SiO2 content is increased.

For the Dielectric properties (Real dielectric constant ԑ’, Imaginary

dielectric constant ԑ”, Tangent of loss angle (Tan δ)), the results evinced raising

and lowering in their value according to the ratio of SiO2 but in general,

lowering in their value with changing measurement field frequency.

For the diametrical strength test, the results elucidated raising when

adding (SiO2) at temperatures 1000 ◦C, 1100 ◦C, and 1200◦C, but up to the

temperature of 1300 ◦C reduces the BaTiO3 diametrical strength value.

Preparation and Characterization Study of Titanium dioxide Nanoparticles Doping with Nanometals

By: Muna Muzahim Abbas, Supervised By: Asst. Prof. Dr. Mohammed Siham Rasheed

year: 2021

abstract

In this research, titanium dioxide nanoparticles were synthesized by the solid

state reaction method, then all of the aluminum and copper materials were

added to the nanoscale size and were added in three ratios that are (3%, 5% and

7% (wt.)) and the use of the dry press method through a hydraulic press from

one direction, using a mold of diameter (10 mm) to obtain a ceramic

compressed dimension that was firing at a temperature of 1100 °C.

The physical properties, which include loss mass. The addition of (3% wt.)

ratio for aluminum has a large percentage of mass loss. Also adding copper (3%

wt.) had a large mass loss in the shrinkage amount of the material, when adding

aluminum at a (3% wt.) ratio it found that the highest shrinkage percentage

among the added rates. Adding copper on (7% wt.) ratio is the highest among

shrinkage the added rates.

The thermal conductivity are studied for all samples that include pure with

the added proportions and compared between them when adding the

proportions for aluminum the ratio of (5% wt.) is the highest conductivity

between the used ratios. As for copper, also; it was found that the highest

conductivity evaluated is for the ratio (5% wt.).

The dielectric constant property and the effect of adding the metal to titanium

dioxide are studied. It was found percentage (3% wt.) for aluminum being the

highest, while the added rates for copper are the highest percentage is (5% wt.) .

For the mechanical properties, which included the hardness and the Brazilian

Test, when adding percentage from aluminum toTiO2 (3% wt.) Ratio showed is the highest hardness value between other ratios and when

adding copper also the highest hardness found on (3% wt.) ratio,

As well as, the material strength value the compressibility imposed on it

through the Brazilian test when adding aluminum a compressibility of (5% wt.)

was obtained, when copper was added, the highest compressive value was

obtained with respect to the added proportions which was (7% wt.).

Material’s structure of the samples are studied using XRD to study the phases

during the temperature of 1100 °C, how the phase shifted when adding

aluminum and copper to titanium dioxide.

As well as, the vibrational effects of atoms through FTIR and the ability of

the molecules to absorb are reported. The samples surface, intermolecular

bonding through SEM and chemical concentrations were studied through EDX

and also taking surface pictures of the samples through an optical microscope,

know the surface morphologies and roughness all samples by AFM

Preparation of porous silicon carbide ceramic by exploiting gases emitted from chemical reactions

By:Lara Abd Al- Hakeem shalal, Supervised By: Prof. Dr. Shihab Ahmed Zaidan

year: 2021

abstract

Silicon carbide described among the advanced ceramic materials and has

wide applications. Porous ceramics were fabricated from silicon carbide in this

research.

Silicon carbide characterized by a high melting temperature.so, it is always

referred to as being linked to materials with a lower melting point, including

bentonite raw as one of the clays types. Generating gases technique from the

reaction of hydrochloric acid HCl with aluminum was used in (silicon carbide bentonite) suspension , And by molding bentonite in a rubber silicon mold,

adding different weight ratios of bentonite (10, 15, 20, 25, and 30 wt.%) to

prepare high-porosity bodies, and then drying and firing at (1100 and 1300oC).

the X-ray diffraction analysis results were studied, it was founded that the main

phases appeared after the firing process were (α and β –SiC) with quartz and

mullite, where a part of (β –SiC) transformed into (α-SiC) when the temperature

rises from (1100 OC to 1300 OC) with the increase of both the mullite phase and

the transformation of a part of the Quartz to Tridymite and Cristobalite.

The increase of bentonite led to an increase in the pH up to (10.3) to an increase

in the basicity of the suspension, which means that the energy reaction could be

increased by adding both hydrochloric acid HCl and aluminum.

The porosity of the prepared samples measured, it was found that it decreased

with the increase in bentonite percentage after the firing process. The porosity

values ranged between (57.4% and 72.3%). Also the same behavior was for the

water absorption rate, and it ranged between (67.4% and 82.2%). As for the

bulk density was increased with percentage of bentonite and the firing

temperature increases. In general, its value ranged from (0.88 to 1.25 g/cm3

), so

the hardness and compressive strength was increased with increasing the

percentage of added bentonite in the range from (4.35 MPa to 6.35 MPa.)

These values were good within the characterization of porous bodies. As for the

thermal properties, the thermal conductivity coefficient decreased with an

increase in the added bentonite percentage.

The thermal conductivity Values ranged between (9.5 W/m.k and 18.6 W/m.k)

when firing at (1100oC), but it increased with the increase of firing temperature up to (1300oC) and ranged between (11.3 W/m.k and 19.8 W/m.k). These values

were within the expected of silicon carbide and bentonite ranged between

(623J/kg.k and 661 J/kg.k). As for the permeability of water, it was measured in

Darcy’s method and its value was great compared to the permeability of other

porous bodies and ranged between (2×10-9 m

2 and17×10-9 m

2

) and its behavior

was similar to that of porosity.

From the above results it was clear that this type of porous (SiC-bentonite)

composites can be used in fluid filtration with high efficiency especially at high

temperatures. In addition the shape of the pores connected to the surface was

variable depending on both the bentonite additives and firing temperature. This

change includes the pores size and the samples surface distribution and this was

approved using optical microscope image

Modification the Properties of Zirconia by Multi-Wall Carbon Nanotube and Study their Biocompatibility

By: Hadeer Shehab Ahmed Al-Hadithi, Supervised By: Dr. Sadeer Mowafaq Majeed & Asst. Prof. Dr. Duha Saadi Ahmed

year: 2020

abstract

In this study, zirconia matrix stabilized in the tetragonal phase was

prepared by adding yttrium oxide (3% mol.Y2O3) with a homogeneous

distribution for different weight additions of (2%, 5%, 7%, and 10%) wt. of F[1]MWCNTs as reinforced to form (3% mol.Y2O3-ZrO2 / F-MWCNTs )

nanocomposite materials using pressing uniaxially (624) MPa in the cylindrical

metal-die to form pellets of (10 mm diameter), Then, the pellets were sintered in

air at (1550 °C) for two hours.

The results showed that changing the percentage of reinforcement and

matrix has a great influence on the measured properties and as follows:

The samples were tested to obtain the physical and mechanical properties

of samples depending on the distribution of F-MWCNTs in the matrix as the

densities (Green, Bulk, and Theoretical), porosity and linear shrinkage. The

maximum values of densities can be at the ratio (2% wt.) of F-MWCNTs; also

the minimum values of porosity and linear shrinkage can be at the ratio (2% wt.)

of F-MWCNTs

Besides, the mechanical properties where the microhardness was studied

by vickers indentation method and Brazilian test to demonstrate the toughness.

The maximum values of the vickers hardness and compression strength obtained

at the ratio (2% wt., 5%wt.) of F-MWCNTs.

The samples were characterized by using XRD analysis to determine the

phase composition of samples and the microstructure, and the fracture surface of

the materials was studied using SEM and EDS, also was characterized by using

FTIR to determine the vibrational mode after treated MWCNTs.Besides, the cell viability of samples by MTT assay was studied to

investigate the activity of composite (3% mol. Y2O3-ZrO2) (10%) wt. F[1]MWCNTs in killing the tumor cells. The results elucidated the best antibacterial

activity of samples at concentration (150 µg.mL-1

) of the ratio (7% wt., 10% wt.)

of F-MWCNTs, where three types of bacteria pathogen (E. coli, P. aeruginosa

and S. aureus) manifested an excellent antibacterial activity , also the good

results of adhesion bacterial against bacteria pathogen (E. coli) can be seen at the

ratio (7% wt., 10% wt.) of F-MWCNTs where proved a potential application in

teeth/bone implantation to decrease the bacterial load in some areas with a high

exposure to bacterial contamination.

Preparation of Electrical Insulators from Local Raw Materials and Study the Effect of Nano Additives on the Dielectric Properties

By: Lubna Jaleil Ibraheim, Supervised By: Dr. Mojahid Mohammed Najim

year: 2020

abstract

Porcelain is one of the most important ceramic materials used as insulation

and to improve the isolation properties were added rice husk ash and nano

materials (Alumina, Titania) were added separately.

Porcelain mixtures were prepared from Iraqi raw materials; five mixtures

(A, B, C, D and E) were produced with different percentages of kaolin, silica

sand and feldspar. The powders were compacted as discs shape with diameter

(13 mm) by semi-dry pressing with (2 tons) applied pressure for (2 minutes).

The samples were sintered at two different temperatures (1200⁰C and

1250⁰C), and the socking time was (2 hr).

XRD and SEM of pure porcelain samples showed that the main crystalline

phases of porcelain were mullite and quartz.

It was observed that with increase sintering temperature, the porosity and

water absorption decreased, while the bulk density and shrinkage increased, and

it can be observed that the porosity, water absorption, shrinkage deceased while

the bulk density increase when increased feldspar content.

The mechanical properties of pure porcelain samples were measured. As

for the dielectric properties of pure porcelain, it can be noticed with increasing

of feldspar percentage, dielectric constant decreased while the dielectric strength

increased.

Where, the best sample was prepared physical, mechanical and dielectric

properties obtained the C sample (50% kaolin, 25% feldspar, and 25 % silica

sand) sintered at 1250°C.Rice husk ash was prepared and added to mixture C instead of quartz in

different percentages (5, 10, 15, 20) wt %, formed with desk shape and sintered

at 1250°C, it was observed the dielectric constant and the dielectric strength

increase with increase rice husk ash.

Nano materials (nano alumina and nano titania) were added to mixture C in

different percentages (0.5, 1, 1.5, 2) wt%, each nano material was separately,

formed with desk shape and sintered at 1250°C.

Dielectric constant, dielectric loss and dielectric strength increased when adding

nano alumina and nano titania to porcelain.

Preparation And Characteristics Of Ceramic Crude Petroleum Filters From Local Raw Materials

By: Khulood haleem Yousif, Supervised By: Dr. Enas Muhi Hadi

year: 2020

abstract

Crude petroleum is a main source of energy, and has different quality

around the world which affected the petroleum refining industry.

In this work porous ceramic was prepared from Iraqi Local kaolin with

(70%) and alumina (30%), for the purpose of improvement the

properties of filter and enhancement the formation of the mullite phase.

These materials used considered low cost materials, environmentally

friendly, harmless and recyclable. Furthermore, there were natural

additions of palm fronds (P.F) in different ratios (5, 10, 15, 25, 35 and

45) % and different sizes (fine, medium and coarse) in order to create

pores materials.

Porous ceramic specimens was formed in disc shape with diameter (25)

mm by dry pressing with a load of (5 tons) for testing while others

formed in balls shape with diameters ranging between (20-25) mm by a

cold forming. porous ceramic specimens were firing at 1200ᵒC by a

firing program with a soaking time for (2hr).

The practical results obtained for the porous ceramic based on the

additives ratio showed that the apparent porosity and water absorption

ratio increased with increasing of (P.F) addition ratios. The highest

apparent porosity ratio for filter was (60.7%) with 45% ratio of fine (P.F),

the highest water absorption ratio for filter was (89.3%) with 45% ratio of

fine (P.F).

Apparent density decreased with the increase of (P.F) additive ratio, the

lowest apparent density for filter was (0.68 g/cm3

) with 45% ratio of fine

(P.F).While, the mechanical properties decreased with the increase of

(P.F) additive ratio.

Crude petroleum treated by filters with 30% ratio of fine, medium and

coarse (P.F), Tests conducted on Properties (Physico-chemical) of crude

petroleum for all filter for 7 days, The results elucidated that the filters

with30% ratio of fine (P.F) were better in purifying crude petroleum

therefore filters with this ratio submerged for 14 days. The result obtained for crude petroleum manifested that the (American

Petroleum Institute gravity (API) for crude petroleum was (24.70), API

for crude petroleum after treated with filter of 30% ratio of fine (P.F) for

14 days was (32.5). Moreover, Sulfur content for crude petroleum was

(3.76wt.%), while sulfur content for crude petroleum after treated with

filter of 30% ratio of fine (P.F) for 14 days was (2.6wt. %). Carbon

residue for crude petroleum was (8.8wt.%), while Carbon residue for

crude petroleum after treated with filter of 30% ratio of fine (P.F) for 14

days was (4.53wt.%). Also, Asphaltenes content for crude petroleum was

(6.68wt.%) compared to crude petroleum after treated with filter of 30%

ratio of fine (P.F) for 14 days was (1.6wt.%). Finally, Metallic content

(Ni, V, Fe) for crude petroleum were respectively (32,86,1.32) ppm,

while these metallic content for crude petroleum after treated with filter

of 30% ratio of fine (P.F) for 14 days were respectively

(11.43,47.52,0.73) ppm.

All these results obtained within the required standards by the companies

importing Iraqi crude petroleum.

Manufacturing of Copper Foam via Dissolution and Sintering  Process for Industrial Water Purification

By: Nour Ali Badi, Supervised By: Dr. Ali Abadi Altayef Aljubouri.

year: 2020

abstract

Copper foams were manufactured by using powder metallurgy technique,

then the dissolution and sintering process was conducted Copper powder with

particle size (0.45 – 1.18 mm) was used as a raw material with K2CO3 and Sugar

powder having same particle size between (0.2 – 1.18 mm) as a space holder.

Porosity, foam density, compressive strength ,Young’s modulus, yield stress,

energy absorption and pore size were investigated. The optical microscope and

scanning electron microscopy have been used to investigate the pores.

The variables that were used in this study are space holder ( K2CO3 and Sugar)

content, the particle size of Cu , K2CO3 and Sugar. A sintering process for all

samples at temperature 875°C for 3 hours have been carried out. .

The foam containing K2CO3 between (30-50 wt. %) at dissolution time (48

hrs) with compaction pressure (200 MPa), in group 1 Copper particle size

between ( 0.045 – 0.075mm ) , porosity increased from (26.15 %) to (83%) with

increasing the pore size between (0.130 to 0.251 mm), while the foam density

decreased from (6.617) to (1.6) g/cm3

, yield stress decreased from (6) to (1.3)

MPa, compressive strength decreased from (6.7) to (2.9) MPa and e absorption

energy decreased from (1.77) to (1.08) MJ/m3

.

The foam containing K2CO3 between (30-50 wt. %) at dissolution time (48 hrs)

with compaction pressure (200 MPa), in group 2 revealed that the particle size

of copper between (0.045–1.18 mm), porosity increased from (26.15 %) to

(80%) with increasing the pore size between (0.120 to 0.608 mm), while the

foam density decreased from (6.617) to (1.79) g/cm3

.

In group 3, the foam containing Sugar between (30-50 wt. %) at dissolution

time (48 hrs) with compaction pressure (200MPa) showed that the particle size

of copper is between ( 0.045 – 0.075mm ) , porosity increased from (26.15 %) to

(84%) with increasing the pore size between (0.328 to 0.457 mm), while the

foam density decreased from (6.617) to (1.36) g/cm3

, yield stress decreased

from (0) to (1.25) MPa, compressive strength decreased from (7.4) to (2.8) MPa

and e absorption energy decreased from (0.93) to (0.622) MJ/m3. The group 4 is same as in group 3, but the particle size of copper is between

(0.045–1.18 mm), porosity increased from (26.15 %) to (84%) with increasing

the pore size between (0.346 to 0.507 mm), while the foam density decreased

from (6.617) to (1.37) g/cm3

.

Finally, The group 5 is like in group 3 and 4, but the particle size of copper is

between (0.075-1.18 mm), porosity increased from (26.15 %) to (82.5%) with

increasing the pore size between (0.318 to 0.352 mm), where as the foam

density decreased from (6.617) to (1.53) g/cm3

.

From the atomic adsorption test, the results showed that using K2CO3 as a

space holder is more effective than sugar in the elimination of chromium from

the industrial water. The best value of eliminating chromium was obtained by

group 1 sample with K2CO3 content 30%, in which the chromium content

decreased from 1444.50 ppm in the industrial water before filtration to 1106.09

ppm after filtration, while in group 3 with using the same content of sugar as

space holder, the chromium content decreased from 1444.50 ppm in the

industrial water before filtration to 1207.69 ppm after filtration.

Study of The Effect of Doping on Structural, Optical and Electrical Properties of (ZnS) Thin Films Prepared by Chemical Spray Pyrolysis

By: Shanaz Hussein A. Al Sormeeri, Supervised By: Assist.prof.Dr. Rana Mahdi Salih

year: 2019

Abstract

This work aims to enhance acoustic and thermal insulation

properties for polymeric composite by adding nanoclay and rock wool as

reinforcement materials with different ratios. A polymer blend of

(epoxy+ polyester) as matrix materials was used, and hand lay-up

technique was used to manufacture the castings. Epoxy and polyester

were mixed in different weight ratios (50:50, 60:40, 70:30, 80:20, and

90:10) wt. % of (epoxy: polyester) respectively. The optimum mixing

ratio (OMR) was decided upon the highest value of impact test carried

out on the blends of the above mentioned ratios, which showed that the

(80:20)wt.% epoxy: polyester respectively had the highest impact

strength value, hence was selected as a matrix for the composite. Nano

clay (Kaolinite) with ratios (5 and 7.5% ) wt.% , also hybrid

reinforcement materials involving (Kaolite 5 & 7.5 % wt.% + 10%

volume fraction of rockwool ) were added as reinforcement materials to

the optimum sample.

The results show that the addition of nanoclay in a percentage of 7.5

wt.% Leads to the highest sound insulation, such that the sound intensity

for low frequencies was 99.8 dB, reaching to 101 dB at high frequencies

(10000 Hz), suggesting much lower values than the unreinforced blend,

of which the sound intensity started from 107.2 dB to 108.7 for the same

range of frequencies.

Thermal conductivity results showed that the nanocomposite with

7.5 % wt. has the lowest value (about 0.443 W/m.°C). The result of water

Absorption showed that the diffusivity varied according to the type of

material and its temperature. SEM images showed that there is no interface between the matrix phases so they couldn’t be distinguished apart.

Mechanical properties (bending behavior, compressive strength,

impact strength and flexural strength) were studied for these specimens.

The results showed that the blend reinforced with nano clay in a weight

fraction 7.5% and hybridized with rockwool volume fraction 10% had the

lowest deflection and the highest value of Young’s modulus

(1889.49)MPa in bending, while blend reinforced with 5%wt. nanoclay

and 10%vol. rockwool showed the highest value of compressive strength

(396.95) MPa. The reinforcement with nanoclay reduced the impact

strength, such that the lowest impact strength was 0.0055 KJ/m2

for (blend+5% nanoclay). The results of flexural test showed that the

(polyester+ epoxy) blend have the highest value of flexural strength

(57.4MPa). The reinforcement with 5%wt. fraction of nanoclay and

10%vol. fraction of rockwool have led to a reduction in flexural strength

to the lowest value, which was 16.53 MPa.