HIGHER TECHNOLOGICAL INSTITUTE

Supervision : Dr/ Manal Amin Eng/Emad Said

STIR CASTING FURNACE

[1]

Contents INTRODUCTION ............................................................................................................................................. 4

CHAPTER 1 .................................................................................................................................................... 6

Stir Casting .................................................................................................................................................... 6

Definition .................................................................................................................................................. 6

Process variables and their effects on properties: ................................................................................... 6

1-Speed of Rotation: ............................................................................................................................. 6

2-Pouring Temperature: ....................................................................................................................... 6

3-Pouring speed: ................................................................................................................................... 6

4-Mould Temperature: ......................................................................................................................... 6

5-Mould Coatings: ................................................................................................................................. 7

6-Mould Life: ......................................................................................................................................... 7

CHAPTER 3 .................................................................................................................................................... 8

The Stir Casting Furnace For Copper And Nano Material ............................................................................. 8

The concept of design ............................................................................................................................... 8

the material selection ............................................................................................................................... 8

1- The casing ...................................................................................................................................... 8

2- The insulator ............................................................................................................................... 10

3- The heating coils ......................................................................................................................... 12

4- The thermocouples ..................................................................................................................... 14

5- The crucible ................................................................................................................................. 16

6- The stirring rod and the injection cylinder .................................................................................. 17

The design ............................................................................................................................................... 18

The steps of work .................................................................................................................................... 21

Safety ...................................................................................................................................................... 22

CHAPTER 4 .................................................................................................................................................. 24

The Effect Of Nano Material On Brass ........................................................................................................ 24

The Brass ................................................................................................................................................. 24

The Properties ..................................................................................................................................... 24

carbon nanotubes ................................................................................................................................... 24

The properties ......................................................................................................................................... 25

1- the strength................................................................................................................................. 25

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2- Hardness ..................................................................................................................................... 25

3- Electrical properties .................................................................................................................... 25

4- Thermal properties ..................................................................................................................... 25

5- The toxicity .................................................................................................................................. 25

Nano aluminum oxide ............................................................................................................................. 26

Aluminum Oxide Nanoparticles (Al2O3) Product Features: ............................................................... 26

Aluminum Oxide Nanoparticles (Al2O3) Applications: ....................................................................... 26

The difference between the composite CNT/Cu and the Cu in properties ............................................ 27

thermal properties ...................................................................................................................... 27

the mechanical properties .......................................................................................................... 27

CHAPTER 5 .................................................................................................................................................. 28

The Operation Manual ................................................................................................................................ 28

References .................................................................................................................................................. 29

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TABLE OF FIGURES Figure 1: stir casting ...................................................................................................................................................... 4

Figure 2: pressure impregnation/resin transfer molding ............................................................................................... 5

Figure 3: wet wrapping .................................................................................................................................................. 5

Figure 4: pouring metal in a mold.................................................................................................................................. 6

Figure 5: stainless steel sheet metal .............................................................................................................................. 8

Figure 6: aluminum sheet metal .................................................................................................................................... 8

Figure 7: refractory bricks ............................................................................................................................................ 11

Figure 8: Example for heat from electricity ................................................................................................................. 12

Figure 9: Nichrome ...................................................................................................................................................... 13

Figure 10: thermocouples description ......................................................................................................................... 14

Figure 11 : clay graphite crucibles ............................................................................................................................... 16

Figure 21 : the casing .................................................................................................................................................. 18 Figure 13: the crucible ................................................................................................................................................. 18

Figure 14: the refractory bricks .................................................................................................................................... 19

Figure 15: ceramic fiber sheet ..................................................................................................................................... 19

Figure 16: the stirring rod ............................................................................................................................................ 19

Figure 17: the heating coils .......................................................................................................................................... 20

Figure 18: the furnace assembly .................................................................................................................................. 20

[4]

INTRODUCTION

Most people do not realize the extent to which composites are part of our everyday lives.

Why have they invaded our home, our automobiles and our places of work? There are many

reasons. In today's context, composites are a layers of a reinforcing material bonded together

with a chemical compound.

The composite materials have a better properties compared to the matrix material (improve

properties) like : Light Weight, High Strength, Strength Related to Weight - Strength-to-

weight ratio, Corrosion Resistance, High-Impact Strength, Design Flexibility, Part

Consolidation, Dimensional Stability, Nonconductive, Nonmagnetic Radar Transparent, Low

Thermal Conductivity, Durable.

And There are too many manufacturing process to make composite materials like:

1- Powder metallurgy

2- Stir casting

3- Pressure Impregnation/Resin Transfer Molding

4- Wet wrapping

The powder metallurgy is the process of blending fine powdered materials, pressing them into

a desired shape or form (compacting), and then heating the compressed material in a

controlled atmosphere to bond the material (sintering).

Stir casting is the process of stirring molten metals are used for continuous stirring particles

into metal alloy to melt and immediately pour into the sand mold then cooled and allow to

solidify. In stir-casting, the particles are often tends to form agglomerates, which can be only

dissolved by vigorous stirring with high temperature.

Figure 1: stir casting

Pressure Impregnation/Resin Transfer Molding This is a high-tech process in which

fiberglass cloth is dry wrapped onto a mandrel or shaped mandrel. A vacuum is pulled on the

material to remove moisture and air while resin floods the chamber at high pressure. This

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process yields a greater cloth to resin ratio, by weight, making it stronger, so it is ideal for

parts that require higher mechanical loads.

Figure 2: pressure impregnation/resin transfer molding

Wet wrapping: This is the manufacturing process of making composite material by hand

wrapping fiberglass cloth around a mandrel or shaped mandrel, while applying resin. While

being more labor intensive, it is ideal for parts with low mechanical loads or parts that have

thicker cross sections.

Figure 3: wet wrapping

In this experiment we will use stir casting to make our composite that consist of:

1- Bronze as a matrix and Nano carbon tubes

2- Bronze as a matrix and Nano aluminum oxide

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CHAPTER 1

Stir Casting

Definition Stir Casting is a liquid state method of composite materials fabrication, in which a dispersed

phase (ceramic particles, short fibers) is mixed with a molten matrix metal by means of

mechanical stirring. The liquid composite material is then cast by conventional casting

methods and may also be processed by conventional Metal forming technologies

Process variables and their effects on properties:

1-Speed of Rotation:

The control of mold speed is very important for successful production of casting.

Rotational speed also influences the structure, the most common effect of increase in

speed being to promote refinement and instability of the liquid mass at very low speed. It

is logical to use the highest speed consistent with the avoidance of tearing.

2-Pouring Temperature:

Pouring temperature exerts a major role on the mode of solidification and needs to

determine partly in relation to type of structure required.

Low temperature is associated with maximum grain

refinement and equiaxed structures while higher temperature

promotes columnar growth in many alloys. However practical

consideration limits the range .The pouring temperature must

be sufficiently high to ensure satisfactory metal flow and

freedom from cold laps whilst avoiding coarse structures.

3-Pouring speed:

This is governed primarily by the need to finish casting before

the metal become sluggish; although too high a rate can cause

excessive turbulence and rejection. In practice slow pouring offers number advantages.

Directional solidification and feeding are promoted whilst the slow development of full

centrifugal pressure on the other solidification skin reduces and risk of tearing. Excessive

slow pouring rate and low pouring temperature would lead to form surface lap.

4-Mould Temperature:

The use of metal die produces marked refinement when compared with sand cast but

mould temperature is only of secondary importance in relation to the structure formation.

Its principal signification lies in the degree of expansion of the die with preheating

Figure 4: pouring metal in a mold

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.Expansion diminishes the risk of tearing in casting. In nonferrous castings, the mould

temperature should neither be too low or too high. The mold should be at least 25 mm thick

with the thickness increasing with size and weight of casting

5-Mould Coatings:

Various types of coating materials are used. The coating material is sprayed on the inside of

the metal mould. The purpose of the coating is to reduce the heat transfer to the mould

.Defects like shrinkage and cracking that are likely to occur in metal moulds can be

eliminated, thus increasing the die life. The role of coating and solidification can be adjusted

to the optimum value for a particular alloy by varying the thickness of coating layer. For

aluminum alloys, the coating is a mixture of Silicate and graphite in water.

6-Mould Life:

Metal mold in casting is subjected to thermal stresses due to continuous operation. This may

lead to failure of the mold. The magnitude of the stresses depends on the mould thickness and

thickness of the coating layer, both of which influence the production rate. Deterioration takes

place faster in cast iron mold than in steel mold.

[8]

CHAPTER 3

The Stir Casting Furnace For Copper And Nano Material

The concept of design 1- The furnace must reach brass melting point (1200 oc) and hold it for certain time.

2- The worker should use the furnace easy. Safely and the heat shouldnt harm the worker.

3- The furnace should work with electric heater.

the material selection

1- The casing

It would make from a sheet metal:

This is one of the widely used materials in the construction

industry right. This material is a thin flat sheet commonly

made out of steel, nickel, brass tin, or aluminum. The great

thing about this material is that it is completely ductile and

that means that they can be used recreated to another object

almost very easily. Sheet metal fabrication is a long process

and it usually involves bending and shaping the metal into

its desired shape and thickness. The fabricators can also

give the sheet all sorts of complex hollow shapes or

sections, depending on where the client would use it. Sheet

metal is commonly used in car bodies, airplane wings,

hospital tables, or even soda cans.

With the improvement in technology the production of sheet

metal has become more advanced and that means that

fabricator are now capable of creating high quality sheets for

almost every purpose. The tools have become more efficient

in cutting, perforating, slitting, or seaming the sheets.

Various methods and techniques are being used to complete

the whole process of fabricating metal sheets. Each method

or a combination of them can create the desired materials for

a specific object. This is considered as one of the most

important material that every industry requires so that they

could complete structural and engineering projects.

Figure 6: aluminum sheet metal

Figure 5: stainless steel sheet metal

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There are a lot of metal sheets fabrication companies all over the globe. If you are going to do

business with one, you have to make sure that they have state of the art tools and

technologies. They should also be updated with the new techniques and procedures to make

sure that they metal sheets that they create of you are of the finest quality. You can find some

information about the best metal sheet fabrication providers in your area in the internet. It

would be a wise choice to make a quick research about the most trusted and reputable

companies before making a choice so that you can make sure that the materials that you

would be using for your project is perfect.

The Workaround in Sheet Metal Stamping

The process of bending and molding the sheet metal is referred as sheet metal stamping

fabrication. It uses a wide range of techniques of sheet metal stamping. This technique can

result to various convoluted hollow shapes and sectors. There are a lot of equipments that

can be used in order to accomplish the task of metal stamping. It can be done either using

hand tools or machineries that function automatically.

The process of sheet metal stamping begins with preliminary actions like cutting, slitting or

perforating, using incredible tools that can perform some sort of shearing action. Hand

scissors (for lighter sheets) and power-operated shears are the tools that are being used to do

the preliminary process. There are various kinds of power-generated shearing machines, and

these devices are composed with moveable blades as well as fixed blades.

Another process involved in sheet metal stamping is punching. The sheet metal will be

exposed to a punching machine or often referred as the pressing machine. In this process, a

hole will be created on the metal article, using the appropriate device that will fit the machine.

Clipping is also part of this process wherein the extra metals will be removed.

Next type of sheet metal stamping is shaping. Shaping can be accomplished using various

techniques such as bending or folding. Bending is done using pressbrakes. The other shaping

processes are used to stiffen and mold the sheet metals. Creating tubular sections is one of the

most common shapes being done.

Sections and angles can be made by the process of bending. Coiling, on the other hand, is

done to strengthen the edges of sheet metals. This can be done using, rolling or coiling

devices. Sheet metals will turn to cylindrical or circular shapes, once exposed to roll-forming

machineries.

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2- The insulator

Insulators are materials that have just the opposite effect on the flow of electrons. They do not

let electrons flow very easily from one atom to another. Insulators are materials whose atoms

have tightly bound electrons. These electrons are not free to roam around and be shared by

neighboring atoms.

Some common insulator materials are glass, plastic, rubber, air, and wood.

Insulators are used to protect us from the dangerous effects of electricity flowing through

conductors. Sometimes the voltage in an electrical circuit can be quite high and dangerous. If

the voltage is high enough, electric current can be made to flow through even materials that

are generally not considered to be good conductors. Our bodies will conduct electricity and

you may have experienced this when you received an electrical shock. Generally, electricity

flowing through the body is not pleasant and can cause injuries. The function of our heart can

be disrupted by a strong electrical shock and the current can cause burns. Therefore, we need

to shield our bodies from the conductors that carry electricity. The rubbery coating on wires is

an insulating material that shields us from the conductor inside. Look at any lamp cord and

you will see the insulator. If you see the conductor, it is probably time to replace the cord.

Recall our earlier discussion about resistance. Conductors have a very low resistance to

electrical current while insulators have a very high resistance to electrical current. These two

factors become very important when we start to deal with actual electrical circuits.

Ceramic Fiber

Ceramic Fiber Bulk is produced by the fusion of high-purity alumina/silica raw materials in

an advanced electric arc furnace. The fibers produced are exceptionally clean and consistent

in quality and texture.

Ceramic Bulk Fibers are loose, long and flexible with high refractory properties and are

produced by the "blown" and the "spun" processes. They are used as the base for the

production of blanket, moldable, and vacuum formed board and shapes.

Features

Low thermal conductivity

Low heat storage

Excellent thermal shock resistance

Use limit to 1482 C (2700 F)

Low sound transmission

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Contains no asbestos

Applications

Packing expansion joints in high temperature furnace

low mass kiln cars

Vacuum formed and moldable products

Refractory brick

Refractory brick, also known as fire brick, is a type of specialized brick which is designed for

use in high heat environments such as kilns and furnaces. Numerous companies manufacture

refractory brick in a range of shapes, sizes, and styles, and it can be ordered directly through

manufacturers or through companies which supply materials to people who work with high

heat processing of materials. High quality refractory brick has a number of traits which make

it distinct from other types of brick.

The primarily important property of refractory brick is that it can withstand very high

temperatures without failing. It also tends to have low thermal conductivity, which is

designed to make operating environments safer and more efficient. Furthermore, refractory

brick can withstand impact from objects inside a high heat environment, and it can contain

minor explosions which may occur during the heating process. It may be dense or porous,

depending on the design and the intended utility.

This brick product is made with specialty clays which can be blended with materials such as

magnesia, silicon carbide, alumina, silica, and chromium oxide. The exact composition of

refractory brick varies, depending on the applications it is designed for, with manufacturers

disclosing the concentrations of ingredients and recommended applications in their catalogs.

Using refractory brick which is not designed for the application can be dangerous, as the

bricks may fail, cracking, exploding, or developing other problems during use which could

pose a threat to safety in addition to fouling a project.

Even though it is specifically designed for high heat environments,

refractory brick will eventually start to fail. It can crack, flake, or

break down over time, necessitating regular inspection of

environments where this product is used. If damaged bricks are

identified, they need to be removed and replaced with new bricks to

ensure that the device operates as intended, and to reduce the risk of

injuries, equipment failure, and other problems. The bricks can also

accumulate soot and other materials through routine use, and they

may need to be scrubbed down periodically.

Some places where refractory brick can appear include: fireplaces, wood stoves, cremation

furnaces, ceramic kilns, furnaces, forges, and some types of ovens. The earliest refractory

Figure 7: refractory bricks

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bricks were developed around the 1800s, with several inventors contributing radical

reworking to make such products safer and more reliable. Companies continue to experiment

with recipes and manufacturing process to develop even better products which will increase

efficiency and safety while cutting down on maintenance costs.

3- The heating coils

Making heat from electricity

In school we learn that some materials carry electricity well,

others badly. The good carriers of electricity are called

conductors, while the poor carriers are known as insulators.

Conductors and insulators are often better described by talking

about how much resistance they put up when an electric current

flows through them. So conductors have a low resistance

(electricity flows through them easily) while insulators have a

much higher resistance (it's a real struggle for the electricity to

get through). In an electric or electronic circuit, we can use

devices called resistors to control how much current flows; using

a dial to increase the resistance and lower the current in a

loudspeaker circuit is a way of turning down the volume, for

example.

Resistors work by converting electrical energy to heat energy; in

other words, they get hot when electricity flows through them.

But it's not just resistors that do this. Even a thin piece of wire

will get hot if you force enough electricity through it. That's the

basic idea behind incandescent lamps (old-fashioned, bulb-shaped lights). Inside the glass

bulb, there's a very thin coil of wire called a filament. When enough electricity flows through

it, it glows white hot, very brightlyso it's really making light by making heat. Around 95

percent of the energy a lamp like this uses is turned into heat and completely wasted.

Now forget the lightwhat if the heat were the thing we were really interested in? Suddenly,

we find our wasteful incandescent lamp is actually very efficient, because it converts 95

percent of the energy we feed into it to heat. Fantastic! Only there's a problem. If you've ever

got close to an incandescent lamp, you'll know it gets hot enough to burn you if you touch it

(don't be tempted to try). But if you stand even a meter or so away, the heat from something

like a 100-watt lamp is far too feeble to reach you.

So what if we wanted to build an electric heater broadly along the same lines as an electric

lamp? We'd need something like a scaled-up lamp filamentmaybe 2030 times more

Figure 8: Example for heat from electricity

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powerful so we could really feel the heat. We'd need a fairly robust material (one that didn't

melt and lasted a long time through repeated heating and cooling) and we'd need it to give off

lots of heat at a reasonable temperature (maybe when it glowed red hot instead of white hot,

so it didn't blind us). What we're talking about here is the essence of a heating element: a

sturdy electrical component designed to throw out heat when a big electric current flows

through it.

What are heating elements ?

A typical heating element is usually a coil, ribbon, of strip of wire made from nichrome that

gives off heat much like a lamp filament. When an electric current flows through it, it glows

red hot and converts the electrical energy passing through it into heat, which it radiates out in

all directions. Nichrome is an alloy (a mixture of metals and sometimes other chemical

elements) that consists of about 80

percent nickel and 20 percent

chromium (other compositions of

nichrome are available, but the

8020 mix is the most common).

There are various good reasons

why nichrome is the most popular

material for heating elements: it

has a high melting point (about

1400C or 2550F), doesn't

oxidize (even at high

temperatures), doesn't expand too

much when it heats up, and has a

reasonable (not too low, not too

high, and reasonably constant)

resistance (it increases only by

about 10 percent between room temperature and its maximum operating temperature).

Types of heating elements

There are lots of different kinds of heating elements. Sometimes the nichrome is used bare, as

it is; other times it's embedded in a ceramic material to make it more robust and durable

(ceramics are great at coping with high temperatures and don't mind lots of heating and

cooling). The size and shape of a heating element is largely governed by the dimensions of

the appliance it has to fit inside and the area over which it needs to produce heat. Hair curling

tongs have short, coiled elements because they need to produce heat over a thin tube around

which hair can be wrapped. Electric radiators have long bar elements because they need to

Figure 9: Nichrome

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throw heat out across the wide area of a room. Electric stoves have coiled heating elements

just the right size to heat cooking pots and pans (often stove elements are covered by metal,

glass, or ceramic plates so they're easier to clean).

In some appliances, the heating elements are very visible: in an electric toaster, it's easy to

spot the ribbons of nichrome built into the toaster walls because they glow red hot. Electric

radiators (like the one in our top photo) make heat with glowing red bars (essentially just

coiled, wire heating elements that throw out heat by radiation), while electric convector

heaters generally have concentric, circular heating elements positioned in front of electric

fans (so they transport heat more quickly by convection). Some appliances have visible

elements that work at lower temperatures and don't glow; electric kettles, which never need to

operate above the boiling point of water (100C or 212F), are a good example. Other

appliances have their heating elements completely concealed, usually for safety reasons.

Electric showers and hair curling tongs have concealed elements so there's (hopefully) no risk

of electrocution.

4- The thermocouples

A Thermocouple is a sensor used to measure temperature. Thermocouples consist of two wire

legs made from different metals. The wires legs are welded together at one end, creating a

junction. This junction is where the temperature is measured. When the junction experiences

a change in temperature, a voltage is created. The voltage can then be interpreted using

thermocouple reference tables to calculate the temperature.

Figure 10: thermocouples description

There are many types of thermocouples, each with its own unique characteristics in terms of

temperature range, durability, vibration resistance, chemical resistance, and application

compatibility. Type J, K, T, & E are Base Metal thermocouples, the most common types of

[15]

thermocouples. Type R, S, and B thermocouples are Noble Metal thermocouples, which are

used in high temperature applications (see thermocouple temperature ranges for details).

Thermocouples are used in many industrial, scientific, and OEM applications. They can be

found in nearly all industrial markets: Power Generation, Oil/Gas, Pharmaceutical, Bio-Tech,

Cement, Paper & Pulp, etc. Thermocouples are also used in everyday appliances like stoves,

furnaces, and toasters.

Thermocouples are typically selected because of their low cost, high temperature limits, wide

temperature ranges, and durable nature

Some types of thermocouples Table1: thermocouples selection

The type used in the furnace was type k

Type K (chromel alumel) is the most common general purpose thermocouple with a

sensitivity of approximately 41 V/C (chromel positive relative to alumel when the junction

temperature is higher than the reference temperature).[9] It is inexpensive, and a wide variety

of probes are available in its 200 C to +1350 C / -330 F to +2460 F range. Type K was

specified at a time when metallurgy was less advanced than it is today, and consequently

characteristics may vary considerably between samples. One of the constituent metals, nickel,

[16]

is magnetic; a characteristic of thermocouples made with magnetic material is that they

undergo a deviation in output when the material reaches its Curie point; this occurs for type K

thermocouples at around 185 C.

Type K thermocouples may be used up to 1260 C in non-oxidizing or inert atmospheres

without rapid aging. In marginally oxidizing atmospheres (such as carbon dioxide) between

800 C1050 C, the chromel wire rapidly corrodes and becomes magnetic in a phenomenon

known as "green rot"; this induces a large and permanent degradation of the thermocouple,

causing the thermocouple to read too low if the corroded area is exposed to thermal gradient.

Another source of drift in type K thermocouples is that near 400 C, a slow reordering in the

chromel wire occurs; this is reversible and leads to hysteresis between heating and cooling.

5- The crucible

A crucible is a container that can withstand very high temperatures and is used for metal,

glass, and pigment production as well as a number of modern laboratory processes. While

crucibles historically were usually made from clay, they can be made from any material that

withstands temperatures high enough to melt or otherwise alter its contents.

Furnace crucibles come in a variety of metal constructions, such as clay-graphite, silicon-

carbide, and more. These materials can resist the extreme temperatures in typical foundry

operations. Silicon carbide has the additional benefit of being a highly durable material.

The modern crucible is a highly heterogeneous, graphite-based composite material, which

relies on its material composition and control of the graphites structural alignment to achieve

the performance required. Crucibles may be as small as teacups or may hold several tons of

metal. They may be fixed in place within a furnace structure or may be designed to be

removed from the furnace for pouring at the end of each melt. Crucibles are used in fuelfired

furnaces, in electric resistance furnaces, in induction furnaces or simply to transfer molten

metal. They come with or without pouring spouts and in a wide variety of traditional and

specialized shapes.

The best approach is to begin with your own detailed

assessment of your operations. You need to fully document and,

where possible, quantify all aspects of your melting, holding

and metal handling processes.

These include:

Figure 11 : clay graphite crucibles

[17]

The capacity, dimensions and type of your furnace

The specific alloy or range of alloys you melt

The melting and/or holding temperatures you maintain

The temperature change rate the crucible will experience

How the crucible is charged

The fluxes or additions used

How the crucible is emptied.

Types of crucibles

Bronze and iron age crucible were shallow clay vessels and the air for the heat was blown

from above. They often had small handles to aid in transport from the furnace to the mold

Silicon carbide crucibles are the most durable and long lasting. They will handle the most

abuse and what, They are the most expensive of the crucibles, but will last for many years

with care.

Graphite crucibles are relatively inexpensive and used by many foundries in sizes up to

60. However they are fragile and do not have very long lives.

Ceramic crucibles are less expensive but not very durable.

The crucible used in the furnace is silicon carbide.

6- The stirring rod and the injection cylinder

The stirrer rod is used for mixing purpose of liquid metal with solid Nano particles. It made

from AISI 310 grade heat resistant and corrosion resistant steel material.

[18]

The design

Figure 11 : the casing

First figure is the casing and it made from steel sheet metal and connecting together by

welding with inside dimension (55cm x45cm x 30cm).

Second figure is the cover and it also made from steel sheet metal with inside

dimension (36cm x 36cm x 10 cm).

The thickness of steel sheet metal is 2cm.

Third figure is a rod that holding the cover and the furnace body together.

Figure 13: the crucible

the crucible is made from carbide calcium with diameter 21,18 height 30cm

[19]

Figure 14: the refractory bricks

The refractory bricks is made from 70% china clay and 30% alumina ( aluminum oxide) with 2 ways to pass

the heating coils through it with dimension (10cm x 5cm x 20cm)

Figure 15: ceramic fiber sheet

The ceramic fiber sheets used to insulate the heat and keep it inside the furnace by put it behind the refractory bricks and on the top of the furnace with its dimension and thickness (2.2 cm)

Figure 16: the stirring rod

The stirring rod made from stainless steel with 70cm length and diameter 13mm and the fan made from

stainless steel too.

[20]

Figure 17: the heating coils

The heating coils is made from nichrome (alloy from nickel chromium) with diameter 2.5mm the furnace

toke 1.5 kg ( 4heating each one have length 120cm).

Figure 18: the furnace assembly

[21]

The steps of work

1- Made the outside casing of sheet metal by arc welding.

2- Locate the area of the crucible and building the bricks far from it by suitable distance but

without holding.

3- Select the heating coils numbers and made its ways in the bricks .

4- Cover the furnace casing from the inside with ceramic fiber.

5- Build the bricks and fix it and fill the holes with powder (calcium carbide ).

6- Made the hole for the exit of heating coils and thermocouples.

7- Cleaning the bricks and make sure that the ways of thermocouples and heating coils is clear .

8- Assemble the heating coils and thermo couples

9- Connect the heating coils in series .

10- Cover the crucible with ceramics.

11- At the top of the furnace put a sheet of ceramic fiber .

12- Prepare the furnace cover to close the cover with furnace to become insulator on insulator.

13- Build the bricks inside the furnace cover and fixing it by silicate calcium.

14- Made outcrop in the furnace cover to fall in the ceramic fiber sheet in the top of furnace .

[22]

15- Made a layer of ceramic fiber on the top of the cover before close it with a sheet metal .

16- Made a hole in the cover to put the rod in it and to put the nanomaterial from it .

17- Made a machining on stir rod so you can wild it with the fan .

18- Fixing the control unit and connect it with the thermo couples and the heating coils.

19- Fixing the motor ( drilling machine )holder on the furnace body so it can stir the

stiring rod and it stir the metal

20- Make a good surface finish for the furnace body so it can by painted.

21- Paint the furnace

22- Check the furnace and test it on the required temperature .

Safety 1- Make sure that the volt enter to the control unit is 220 V

2- Wear a goggles and glaives when working with high temperatures

3- Dont touch things directly from the furnace

4- Dont leave the furnace without notice

5- Acting with furnace from at least 40 cm

6- Dont leave the furnace cover open except when you pouring the molten metal or acting with

the crucible

[23]

7- Dont get close to the crucible or touch it while it hot

8- Put the metal in the crucible before start the heating

9- Dont look vertical into the furnace .

10- Crucibles must always be annealed on 1st use.

11- -They occasionally need to be re-annealed, by returning to the furnace empty and taking it

up to 2000 degrees, then allowing to cool slowly.

12- -should never be over packed with cold metal (metal expands when melting).

13- - should be heated slowly until the furnace gains color.

14- - should be cleaned at the end of the melt.

15- - They should always cool in a warm furnace and never allowed to cool in ambient

temperatures.

16- -Store your crucibles on wood blocks or upside-down. Do not store them in places where

they will get wet or freeze.

17- -The sides and lips should be dressed regularly.

18- -Always examine your crucible carefully before each melt.

[24]

CHAPTER 4

The Effect Of Nano Material On Brass

The Brass Brass is an alloy made of copper and zinc; the proportions of zinc and copper can be varied to

create a range of brasses with varying properties. It is a substitutional alloy: atoms of the two

constituents may replace each other within the same crystal structure.

By comparison, bronze is principally an alloy of copper and tin. Bronze does not necessarily

contain tin, and a variety of alloys of copper, including alloys with arsenic, phosphorus,

aluminum, manganese, and silicon, are commonly termed "bronze". The term is applied to a

variety of brasses and the distinction is largely historical, and modern practice in museums

and archaeology is increasingly to avoid both terms for historical objects in favor of the all-

embracing "copper alloy".

The Properties

bright gold appearance

higher malleability than bronze or zinc

acoustic properties appropriate for use in musical instruments

low friction

soft - may be used where low chance of sparking is necessary

relatively low melting point

easy to cast

not ferromagnetic (which makes it easier to separate from other metals for recycling)

carbon nanotubes Carbon nanotubes (CNTs) are allotropes of carbon with a cylindrical nanostructure.

Nanotubes have been constructed with length-to-diameter ratio of up to 132,000,000:1,[1]

significantly larger than for any other material. These cylindrical carbon molecules have

unusual properties, which are valuable for nanotechnology, electronics, optics and other fields

of materials science and technology. In particular, owing to their extraordinary thermal

conductivity and mechanical and electrical properties, carbon nanotubes find applications as

additives to various structural materials. For instance, nanotubes form a tiny portion of the

material(s) in some (primarily carbon fiber) baseball bats, golf clubs, car parts or damascus

steel.

[25]

The properties

1- the strength

Carbon nanotubes are the strongest and stiffest materials yet discovered in terms of tensile

strength and elastic modulus respectively. This strength results from the covalent bonds

formed between the individual carbon atoms. In 2000, a multi-walled carbon nanotube was

tested to have a tensile strength of 63 gigapascals (9,100,000 psi) (For illustration, this

translates into the ability to endure tension of a weight equivalent to 6,422 kilograms-force

(62,980 N; 14,160 lbf) on a cable with cross-section of 1 square millimetre (0.0016 sq in).)

Further studies, such as one conducted in 2008, revealed that individual CNT shells have

strengths of up to ~100 gigapascals (15,000,000 psi), which is in agreement with

quantum/atomistic models. Since carbon nanotubes have a low density for a solid of 1.3 to 1.4

g/cm3, its specific strength of up to 48,000 kNmkg1 is the best of known materials,

compared to high-carbon steel's 154 kNmkg1.

2- Hardness

Standard single-walled carbon nanotubes can withstand a pressure up to 25 GPa without

deformation. They then undergo a transformation to super hard phase nanotubes. Maximum

pressures measured using current experimental techniques are around 55 GPa. However,

these new super hard phase nanotubes collapse at an even higher, albeit unknown, pressure.

3- Electrical properties

Because of the symmetry and unique electronic structure of graphene, the structure of a

nanotube strongly affects its electrical properties. the nanotube is a moderate semiconductor.

4- Thermal properties

All nanotubes are expected to be very good thermal conductors along the tube, exhibiting a

property known as "ballistic conduction", but good insulators laterally to the tube axis.

Measurements show that a SWNT has a room-temperature thermal conductivity along its axis

of about 3500 Wm1K1; compare this to copper, a metal well known for its good thermal

conductivity, which transmits 385 Wm1K1. A SWNT has a room-temperature thermal

conductivity across its axis (in the radial direction) of about 1.52 Wm1K1, which is about

as thermally conductive as soil. The temperature stability of carbon nanotubes is estimated to

be up to 2800 C in vacuum and about 750 C in air.

5- The toxicity

The toxicity of carbon nanotubes has been an important question in nanotechnology. As of

2007, such research has just begun. The data are still fragmentary and subject to criticism.

[26]

Preliminary results highlight the difficulties in evaluating the toxicity of this heterogeneous

material. Parameters such as structure, size distribution, surface area, surface chemistry,

surface charge, and agglomeration state as well as purity of the samples, have considerable

impact on the reactivity of carbon nanotubes. However, available data clearly show that,

under some conditions, nanotubes can cross membrane barriers, which suggests that, if raw

materials reach the organs, they can induce harmful effects such as inflammatory and fibrotic

reactions.

Under certain conditions CNTs can enter human cells and accumulate in the cytoplasm,

causing cell death.

Nano aluminum oxide

Al2O3 nanoparticles water dispersion with phase stability, high hardness, and good

dimensional stability, it can be widely used in plastics, rubber, ceramics, refractory products.

In particular, it can significantly improve ceramics density, smoothness, thermal fatigue

resistance, fracture toughness, creep resistance and polymer products wear resistance.

Aluminum Oxide Nanoparticles (Al2O3) Product Features:

nano-Al2O3 with small size, high activity and low melting temperature, it can be used for

producing synthetic sapphire with the method of thermal melting techniques. If used as

industrial catalysts, they will be the main materials for petroleum refining, petrochemical and

automotive exhaust purification. In addition, nano-Al2O3 can be used as analytical reagent.

Aluminum Oxide Nanoparticles (Al2O3) Applications:

1- Transparent ceramics: high-pressure sodium lamps, EP-ROM window;

2. Cosmetic filler;

3. Single crystal, ruby, sapphire, sapphire, yttrium aluminum garnet;

4. high-strength aluminum oxide ceramic, C substrate, packaging materials, cutting tools,

high purity crucible, winding axle, bombarding the target, furnace tubes;

5. Polishing materials, glass products, metal products, semiconductor materials, plastic, tape,

grinding belt;

6. Paint, rubber, plastic wear-resistant reinforcement, advanced waterproof material;

[27]

7. Vapor deposition materials, fluorescent materials, special glass, composite materials and

resins;

8. Catalyst, catalyst carrier, analytical reagent;

9. Aerospace aircraft wing leading edge.

The difference between the composite CNT/Cu and the Cu in

properties

thermal properties

The thermal conductivity of the composites was not enhanced by the incorporation of CNTs.

the existence of interface thermal resistance between the CNT and the Cu matrix was

considered to be the main reason for this unexpected low thermal conductivity.

the mechanical properties

the composite become more hard so that mean the hardness increases and the strength

increases but the ductility decreases and the machinability decreases .

[28]

CHAPTER 5

The Operation Manual

1- Connect the electricity cable to 1-phase phase(28A,220V) .

2- Put the brass that will melt in the crucible .

3- Close the cover of the furnace .

4- Turn on the heater from the green push bottom .

5- Adjust the required temperature from the monitor in the control unit.

6- Make the control manual .

7- Wait until the furnace reach the required temperature.

8- Put the stainless steel cylinder in the hole on the top on the furnace cover until it reach inside

the crucible .

9- Put the Nano material in a injector (syringe).

10- Inject the Nano material in the cylinder .

11- Take out the stainless steel cylinder then put the stirrer in its place.

12- Connect the stirrer with the motor (drilling machine ).

13- Turn on the motor .

14- Wait after the furnace reach the temperature minimum 1 hour .

15- In this time the mold and the scoop should be heating .

16- Turn of the furnace from the red bottom in the control unit.

17- Open the cover.

18- Take the molten metal by the scoop and pour it in the mold.

19- Close the cover.

Note: the last three steps should be done quickly .

[29]

References

http://www.genplastics.com/composite-manufacturing.php

http://www.premix.com/why-composites/adv-composites.php

http://www.explainthatstuff.com/heating-elements.html

http://en.wikipedia.org/wiki/Thermocouple

http://www.thermocoupleinfo.com/

http://en.wikipedia.org/wiki/Crucible

http://www.afsinc.org/about/content.cfm?ItemNumber=10490

http://en.wikipedia.org/wiki/Brass

http://en.wikipedia.org/wiki/Carbon_nanotube#Properties

http://www.us-nano.com/inc/sdetail/209