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					   FAKULTI KEJURUTERAAN MEKANIKAL
    UNIVERSITI TEKNOLOGI MALAYSIA

MANUFACTURING PROCESS
       SME 2713

                PROJECT :


   DISC BRAKE
            GROUP 2 MEMBERS
NAME                           MATRIC NO

1. KHAIRUL AMILIN IBRAHIM      AM 050091
2. MOHD EZLAMY ZULKIFLI        AM 050162

3. ADRIAN CYRIL ANTHONY        AM 050010

4. MOHD NORMAIZAL BIN RAHMAN   AM 050198



                LECTURER :

         ZULKEPLI HAJI MUHAMAD
INTRODUCTION

       The disc brake is a device for slowing or stopping the rotation of a wheel. A
brake disc (or rotor in US English), usually made of cast iron or ceramic, is connected to
the wheel or the axle. To stop the wheel, friction material in the form of brake pads
(mounted in a device called a brake caliper) is forced mechanically, hydraulically or
pneumatically against both sides of the disc. Friction causes the disc and attached wheel
to slow or stop.

       Experiments with disc-style brakes began in England in the 1890s; the first ever
automobile disc brakes were patented by Frederick William Lanchester in his
Birmingham factory in 1902, though it took another half century for his innovation to be
widely adopted.

       Modern-style disc brakes first appeared on the low-volume Crosley Hotshot in
1949, although they had to be discontinued in 1950 due to design problems[1]. Chrysler's
Imperial division also offered a type of disc brake from 1949 through 1953, though in this
instance they were enclosed with dual internal-expanding, full-circle pressure plates.
Reliable modern disc brakes were developed in the UK by Dunlop and first appeared in
1953 on the Jaguar C-Type racing car. The Citroën DS of 1955, with powered inboard
front disc brakes, and the 1956 Triumph TR3 were the first European production cars to
feature modern disc brakes[2]. The next American production cars to be fitted with disc
brakes were the 1963 Studebaker Avanti[3] and the 1963 Chevrolet Corvette.

       These brakes offered greater stopping performance than comparable drum brakes,
including resistance to "brake fade" caused by the overheating of brake components, and
recovered quickly from immersion (wet brakes are less effective). Unlike a drum brake,
the disc brake has no self-servo effect and the braking force is always proportional to the
pedal force being applied by the driver.

       Many early implementations located the brakes on the inboard side of the
driveshaft, near the differential, but most brakes today are located inside the wheels.(An
inboard location reduces the unsprung weight and eliminates a source of heat transfer to
the tires, important in Formula One racing.)

       Disc brakes were most popular on sports cars when they were first introduced,
since these vehicles are more demanding about brake performance. Discs have now
become the more common form in most passenger vehicles, although many use drum
brakes on the rear wheels to keep costs and weight down as well as to simplify the
provisions for a parking brake. As the front brakes perform most of the braking effort,
this can be a reasonable compromise.

       The design of the disc varies somewhat. Some are simply solid cast iron, but
others are hollowed out with fins joining together the disc's two contact surfaces (usually
included as part of a casting process). This "ventilated" disc design helps to dissipate the
generated heat and is commonly used on the more-heavily-loaded front rotors.

       Many higher performance brakes have holes drilled or cast through them. This is
known as cross drilling and was originally done in the 1960's on racing cars. Brake pads
will outgas and under use may create boundary layer of gas between the pad and the rotor
hurting braking performance. Cross drilling was created to provide the gas someplace to
escape. Modern brake pads do not suffer as much from outgassing problems and often the
purpose is cosmetic. Rotors may also be slotted, where shallow channels are machined
into the disc to aid in removing dust and gas. Some discs are both drilled and slotted.

       Slotted discs are generally not used on road cars because they quickly wear down
brake pads, however, this removal of material is beneficial to race cars since it keeps the
pads soft and avoids vitrification of their surfaces.

       On the road, drilled or slotted discs still have a positive effect in wet conditions
because the holes or slots prevent a film of water building up between the disc and the
pads. Poorly-made cross drilled rotors (such as those made by simply drilling through a
plain faced rotor) may crack at the holes under use due to metal fatigue.

       New technology now allows smaller brake systems to be fitted to bicycles,
mopeds and now even mountain boards. The market for mountain bike disc brakes is
very large and has huge variety, ranging from simple, mechanical (cable) systems, to
highly expensive and also powerful, 6pot hydraulic disc systems, commonly used on
downhill racing bikes.

       Disc brake rotors are commonly manufactured out of a material called grey iron.
The SAE maintains a specification for the manufacture of grey iron for various
applications. For normal car and light truck applications, the SAE specification is J431
G3000 (superseded to G10). This specification dictates the correct range of hardness,
chemical composition, tensile strength, and other properties that are necessary for the
intended use.

       Historically disc brake rotors were manufactured throughout the world with a
strong concentration in Europe, and America. During the period from 1989 to 2005,
manufacturing of brake rotors has migrated predominantly to China. Today, almost 90%
of brake discs and brake drums are manufactured in China and exported globally.

       Leading manufacturers in China include Laizhou Sanli, MAT (Midwest Air
Technology), Winhere, Longji, and Haimeng.
GREY CAST IRON AS MATERIAL FOR PRODUCTION OF DISC
BRAKE

       Cast iron is the first product obtained in steel making when smelting iron ore. It is the result
of the reduction of ferrous oxides under the action of the carbon in metallurgical coke. Molten cast
iron is in reality a carbon solution in molten iron. When it is cooled a very small part of the carbon
remains in the ferrous solution whereas the majority of it precipitates to form small nodules scattered
throughout the structure of the metal. Usually this unrefined cast iron is not suitable for the majority
of applications but must undergo both physical and chemical processes in order to create the vast and
well-known range of ferrous alloys.

       Disc brakes are commonly manufactured out of grey cast iron. The characteristics taken into
consideration while choosing the material are hardness, tensile strength, wear resistance, thermal
conductivity, machinability, surface finish and shock resistance.


       Grey cast irons contains 2.5 – 4.0 wt% of carbon and 1.0 - 3.0 wt% of silicon. This is one of
many types of materials used in casting. Grey cast iron is formed when the amount of carbon in an
alloy exceeds the amount of carbon that can be contain in austenit dan thus causes the precipitation
of graphite flakes.

                         Fe3C                              3Fe          +     C

       Since carbon -hardly soluble at all in a solid state in iron- precipitates under various forms
and, given its density , represents between 12-15% of total volume, This high carbon, and above all
graphite       content          gives    the       alloy         good       thermal       conductivity.
Lamellar graphite grey cast iron is the most common type and is used for the of production of discs
in braking systems.
        Micrographic examination of lamellar structured gray cast iron. x100 magnification.

       The graphite exist in form of flakes which are normally surrounded by an α-ferrite or pearlite
matrix. Because of these graphite flakes, a fractured surface takes on a gray appearance, hence its
name. The metal expands slightly on solidifying as the graphite precipitates, resulting in sharp
castings. The graphite content also offers good corrosion resistance.

       Graphite acts as a lubricant, improving wear resistance. The exceptionally high speed of
sound in graphite gives cast iron a much higher thermal conductivity. Since ferrite is so different in
this respect (having heavier atoms, bonded much less tightly) phonons tend to scatter at the interface
between the two materials. In practical terms, this means that cast iron tends to “damp” mechanical
vibrations (including sound).

       All of the properties listed in the paragraph above ease the machining of grey cast iron. As
far as grey cast irons are concerned the Brinell hardness values lie between 170 and 250 HB.

       The conductivity, heat capacity and temperature resistance of the rotor material should all be
optimised in order to accommodate the frictional heat generated at the rubbing interface. Grey cast
iron satisfies these requirements but its relatively high density means that the rotor mass is
significant (typically over 5 kg for the front disc of a normal passenger car).

       Ferrite has a hardness of around 100 HB, much lower than that of cast iron which is about
200 HB. Another factor that comes into play in friction is the dimension of the graphite plates that
normally range between 15 mm and 500 mm. The arrangement of these plates must be random as
opposed to organized. The latter case can arise during the disc production process if cooling is not
properly controlled. The cast iron becomes fragile and discs made from it are not appropriate for use.

       In reality, for reasons of performance stability, cost of raw materials and ease of production,
cast iron is the material universally used




        The SAE maintains a specification for the manufacture of grey iron for various applications.
For normal car and light truck applications, the SAE specification is J431 G3000 (superseded to
G10). This specification dictates the correct range of hardness, chemical composition, tensile
strength, and other properties that are necessary for the intended use.


       From the information above we can see that Grey Cast Iron is both cheap and easy to
produce in high volumes, to tightly controlled specifications. It is reasonably light, strong and easy
to machine to high volumes and most importantly, it possesses good thermal conductivity. Another
distinct advantage is that the material’s specific heat increases with temperature, thereby improving
the ability of the brake to absorb additional heat energy created by the action of braking. Finally grey
cast iron due to its structure, has excellent vibration damping characteristics. It is the feature of
thermal conductivity that sets out grey iron as the best material for automotive braking application.
ALUMINIUM AS THE MATERIAL FOR THE HOLDER.

       For the holder the material we have selected is Aluminium alloy. This is because aluminium
have many characteristics that is needed for the holder. The important characteristic are their high
strength to weight ratio, resistance to corrosion by many chemicals, high thermal conductivity,
nontoxicity, and ease of formability and of machinability.
       Aluminium ingot are available for casting. Most aluminium alloys can be machined, formed
and welded with relative ease. There are two types of wrought aluminium :
   1. Alloys that can be hardened by cold working and are not heat treatable.
   2. Alloys that can be hardened by heat treatment.


       Designation of cast aluminium alloys. Designation fro cast aluminium alloys also consist of
four digits. The first digits indicates the major alloy group, as follows:
       1xx.x – aluminium (99.0% minimum)
       2xx.x – aluminium-copper
       3xx.x – aluminium-silicon(with copper and/or magnesium)
       4xx.x – aluminium-silicon
       5xx.x – aluminium-magnesium
       6xx.x – unused series
       7xx.x – aluminium-zinc
       8xx.x – aluminium-tin


       In the 1xx.x series, the second and third digits indicate the minimum aluminium content. For
the other series, the second and third digits have no numerical significance. The fourth digit ( to the
right of the decimal point) indicates product form.
MANUFACTURING PROCESS OF DISC BRAKE AND HOLDER.


The process flow in manufacturing of DISC BRAKE.

    MOLTEN                      DIE                      FINISHING                  QUALITY
    METAL                    CASTING                     (TURNING)                  CONTROL
                             PROCESS
                               (HOT
                             CHAMBER
                             PROCESS)


                                                                                  PACKAGING


The process flow in manufacturing of HOLDER.

MOLTEN                    DIE                            HEAT                 FINISHING
METAL                  CASTING                       TREATMENT                (TURNING)
                       PROCESS                        (NATURAL
                        (COLD                           AGING)
                       CHAMBER
                       PROCESS)
                                                                              QUALITY
                                                                              CONTROL



                                                                              PACKAGING

       Casting is a process by which a fluid melt is introduced into a mold, allowed to cool in the
shape of the form, and then ejected to make a fabricated part or casing. Four main elements are
required in the process of casting: pattern, mold, cores, and the part. The pattern, the original
template from which the mold is prepared, creates a corresponding cavity in the casting material.
Cores are used to produce tunnels or holes in the finished mold, and the part is the final output of the
process. There are two types of casting available;
1.Expeandable
2.Non-expandable
       In manufacturing of disc brake non-expandable mold casting is used. Non- expendable mold
casting differs from expendable processes in that the mold need not be reformed after each
production cycle. There are many types of non-expandable mold casting, die casting is the most
suitable manufacturing process of disc brake.


       In Die-casting the molten metal is injected into the mold under high pressure of 10-210Mpa
(1,450-30,500) psi. This results in a more uniform part, with generally good surface finish and good
dimensional accuracy, as good as 0.2 % of casting dimension. For many parts, post-machining can
be totally eliminated, or very light machining may be required to bring dimensions to size.


Five characteristic of the castings made in die casting process:
1 Precise (dimensions plus or minus as little as .002 inches--over short distances),
2. Have a very smooth surface that can be bright plated without prior polishing and buffing,
3. Have very thin sections (like sheet metal--as little as .050 inches),
4. Produced much more economically than parts primarily machined (multicavity die casting molds
operating at high speed are much more productive than machine tools or even stamping presses),
5. very flexible in design; a single die casting may have all the features of a complex assembly.


       There are two types of die casting process. Which is the Cold Chamber process in which
the holder is manufactured and the Hot Chamber Process for the Disc brake manufacturing.

Cold chamber
       This is the method that is used in the manufacturing of the holder for the disc brake.Cold
Chamber process is primarily for the alloys with higher melting temperatures.In a cold chamber
process, the molten metal is ladled into the cold chamber for each shot from an external furnace.
There is less time exposure of the molten metal to the plunger walls or the plunger.


Hot chamber
       In a hot chamber process the pressure chamber is connected to the die cavity which is
immersed permanently in the molten metal. The inlet port of the pressurizing cylinder is uncovered
as the plunger moves to the open (unpressurized) position. This allows a new charge of molten metal
to fill the cavity and thus can fill the cavity faster than the cold chamber process. The hot chamber
process is used for metals of low melting point and high fluidity.


       Both types of process will use a machines withcylindrical pressure vessel, called an
“accumulator,” which is charged with nitrogen and will boost injection pressure.


       Die casting is a precision, high volume production Process. Die casting production rates can
range from dozens to thousands of parts per hour. Castability is primarily related to a metal’s
melting temperature, followed by other factors including:
• part complexity
• minimum wall thickness
• minimum draft or taper
• required precision of the part
       Alloy type will also influence maximum part size. Although final part weight is considered,
the more accurate determinant is material density that is weight per unit of volume.




                (a)                                        (b)




                (c)                                  (d)
       There are four major steps in the die casting process. First, the mold is sprayed with lubricant
and closed. The lubricant both helps control the temperature of the die and it also assists in the
removal of the casting. Molten metal is then injected into the die under high pressure. The high
pressure assures a casting as precise and as smooth as the mold. Typically it is around 100
MegaPascals. Once the cavity is filled then the pressure is maintained until the casting has become
solid (though this period is usually made short as possible by water cooling the mold). Finally, the
die is opened and the casting is ejected.


        Equally important as high-pressure injection is high-speed injection--required so the entire
cavity fills before any part of the casting solidifies. In this way, discontinuities (spoiling the finish
and even weakening the casting) are avoided even if the design requires difficult-to-fill very thin
sections.


        Before the cycle can be started the die must be installed in the die casting machine (set up)
and brought to operating temperature. This set-up requires 1-2 hours after which a cycle can take
anywhere between a few seconds to a few minutes depending on the size of the casting. A typical die
set will last 500,000 shots during its lifetime with lifetime being heavily influenced by the melting
temperature of the metal or alloy being used.


        A shot occurs every time the die is filled with metal. Shots are different from castings
because there can be multiple cavities in a die, yielding multiple castings per shot. Also the shot
consists not only of the individual castings but also the "scrap" (which, unlike in the case of scrap
from machining, is not sold cheaply; it is remelted) that consists of the metal that has hardened in the
channels leading into and out of the cavities.


        The die must fulfill four primary purposes. First, it must hold molten metal in the shape of
the final casting. The die must also provide a path for the molten metal to reach the casting cavity.
Third, the die is designed to remove heat from the casting. Finally, a die must be able to eject the
solidified casting.


        Because die sets open and shut along a parting line of the casting, design features such as
undercuts cannot be cast without the addition of movable slides in the die set.
       Die casting molds (called dies in the industry) tend to be expensive as they are made from
hardened steel-also the cycle time for building these tend to be long. Also the stronger and harder
metals such as iron and steel cannot be die-cast


       Die Casting machines are rated by how much clamping force they can apply. Typical sizes
range from 100 to 4,000 tons.


       Often there is a secondary operation to separate the castings from the scrap; this is often done
using a trim die in a power press or hydraulic press. An older method is separating by hand or by
sawing, which case grinding may be necessary to smooth the gate mark where molten metal entered
or left the cavity. Finally, a less labor-intensive method is to tumble shots if gates are thin and easily
broken. Separation must follow.
Most die casters perform other secondary operations to produce features not readily castable. Most
common is tapping a hole (to receive a screw).
HEAT TREATMENT FOR HOLDER

        For the HOLDER its hardness is increased in one of the precipitation hardening(heat
treatment) method that is aging. More specifically natural aging. Because several aluminium alloys
harden and become stronger over a period of time at room temperature.




Fig. 1.0
In a hot chamber machine the metal is pumped into the die directly from a furnace of molten metal. Cold
chamber systems transfer molten metal from the furnace to a shot cylinder. The metal is then pushed through
from the cylinder into the die.


        There are factors that can affect the castings quality among them are explained below.
  i.    Cooling rate
        The rate at which a casting cools affects its microstructure, quality, and properties.The
cooling rate is largely controlled by the molding media used for making the mold. When the molten
metal is poured into the mold, the cooling down begins. This happens because the heat within the
molten metal flows into the relatively cooler parts of the mold. Molding materials transfer heat from
the casting into the mold at different rates. For example, some molds made of plaster may transfer
heat very slowly, while a mold made entirely of steel would transfer the heat very fast. This cooling
down ends with (solidification) where the liquid metal turns to solid metal.
       At its basic level a foundry may pour a casting without regard to controlling how the casting
cools down and the metal freezes within the mold. However, if proper planning is not done the result
can be gas porosities and shrink porosities within the casting.


       Fins may also be designed on a casting to extract heat, which are later removed in the
cleaning (also called fettling) procees. Both methods may be used at local spots in a mold where the
heat will be extracted quickly.


       A riser or some padding may be added to a casting. A riser is an additional larger cast piece
which will cool more slowly than the place where is it attached to the casting. Generally speaking,
an area of the casting which is cooled quickly will have a fine grain structure and an area which
cools slowly will have a coarse grain structure.


 ii.   Shrinkage
       Like nearly all materials, metal is less dense as a liquid than a solid, and so a casting shrinks
as it cools -- mostly as it solidifies, but also as the temperature of the solid material drops.
Compensation for this natural phenomena must be considered in two ways.


    a. Volumetric shrinkage
       The shrinkage caused by solidification can leave cavities in a casting, weakening it. Risers
provide additional material to the casting as it solidifies. The riser (sometimes called a "feeder") is
designed to solidify later than the part of the casting to which it is attached. Thus the liquid metal in
the riser will flow into the solidifying casting and feed it until the casting is completely solid. In the
riser itself there will be a cavity showing the metal which was fed. Risers add cost because some of
their material must be removed, by cutting away from the casting which will be shipped to the
customer. They are often necessary to produce parts which are free of internal shrinkage voids.


       Sometimes, to promote directional shrinkage, chills must be used in the mold. A chill is any
material which will conduct heat away from the casting more rapidly that the material used for
molding. All castings solidify with progressive solidification but in some designs a chill is used to
control the rate and sequence of solidification of the casting.
   b. Linear shrinkage
       Shrinkage after solidification can be dealt with by using an oversized pattern designed for the
relevant alloy. Pattern makers use special "shrink rulers" to make the patterns used by the foundry to
make castings to the design size required. These rulers are 2 - 6% oversize, depending on the
material to be cast. Using such a ruler during pattern making will ensure an oversize pattern. Thus,
the mold is larger also, and when the molten metal solidifies it will shrink and the casting will be the
size required by the design.
Finishing Process

       The finishing process chosen for the disc brake and holder is Lathe process.
Because it is the most suitable process since the shape of the disc brake and holder is a
circle plate.


       The lathe operates on the principle of the work being rotated against the edge of a
cutting tool. It is one of the oldest and most important machine tools. The cutting tool is
controllable and can be moved lengthwise on the lathe bed and into any desired angle
across the revolving work.




Driving the lathe
       Power is transmitted to the various drive mechanisms by belt drive and/or gear train.
Holding and rotating the work
       The headstock contains the spindle to which the various work holding attachments
are fitted. The spindle revolves in heavy/duty bearings and is rotated by belts, gears or a
combination of both. It is hollow with the front tapered internally to receive tools and
attachments with taper shanks.         the hole permits long stock to be turned without
dangerous overhang.


Work is held in the lathe by a chuck, faceplate, collet or between centers.




       The outer end of the work is often supported by the tailstock. It can be adjusted
along the ways to accommodate different lengths of work. The tailstock mounts the "dead"
center, and can be fitted with tools for drilling, reaming and threading.   It can also be offset
for taper turning.


Holding, moving and guiding the cutting tool
       The bed is the foundation of a lathe. All other parts are fitted to it. Ways are integral
with the bed. The V-shape maintains precise alignment of the headstock and tailstock, and
serves as rails to guide the travel of the carriage. The cutting tool is mounted on the
carriage.
The carriage controls and supports the cutting tool and is composed of:


-The saddle is fitted to and slides along the ways.
-The apron contains the drive mechanism to move the carriage along the ways using hand
or power feed.
-The cross slide permits transverse tool movement (movement toward or away from the
operator).
-The compound rest permits angular tool movement.
-The tool rest mounts the cutting tool.


Power is transmitted to the carriage through the feed mechanism.


Power is transmitted through a train of gears to the quick change gear box which regulates
the amount of tool travel per revolution of the spindle. The gear train also contains gears for
reversing tool travel.


The quick change gear box is arranged between the spindle and the lead screw. It contains
gears of various ratios which makes it possible to machine various pitches of screw threads
without changing loose gears. Longitudinal (back-and-forth) travel and cross (in-and-out)
travel is controlled in the same manner.


An index plate provides instructions on how to set the lathe shift levers for various thread
cutting and feed combinations. It is located on the face of the gear box. The large numbers
on the index plate indicate the number of threads that can be cut per inch or pitch of metric
threads. The smaller figures indicate the carriage longitudinal movement, in thousandths of
an inch or in mm for each spindle revolution.


The lead screw transmits power to the carriage through a gearing and clutch arrangement
in the carriage apron. Feed change levers on the apron control the operation of power
longitudinal feed and power cross feed.
When place din neutral, the half-nuts may be engaged for thread cutting. The gear
arrangement makes it possible to engage power feed and half- nuts simultaneously. The
half-nuts are engaged ONLY for thread cutting and are NOT used as "automatic" feed for
regular turning.


       For Disc Brake

Facing. Facing is the producing of a flat surface as the result of a tool's being fed across the end of
the rotating workpiece. Unless the work is held on a mandrel, if both ends of the work are to be
faced, it must be turned end for end after the first end is completed and the facing operation repeated.
The cutting speed should be determined from the largest diameter of the surface to be faced. Facing
may be done either from the outside inward or from the center outward. In either case, the point of
the tool must be set exactly at the height of the center of rotation. because the cutting force tends to
push the tool away from the work, it is usually desirable to clamp the carriage to the lathe bed during
each facing cut to prevent it from moving slightly and thus producing a surface that is not flat. In the
facing of casting or other materials that have a hard surface, the depth of the first cut should be
sufficient to penetrate the hard material to avoid excessive tool wear.




The type of turning process that we use to produce disc brake is facing. This because what
we need is the surface of facing like the picture below:


                             The distance between the line is so small. The picture just to show the
                             surface pattern after finishing.
         For the Holder


      First we do the same type of turning for disc brake to the holder. After the facing finishing, we
make the chamber between first and second facing called taper turning. It is shown in the picture
below.




     For the side, we make the finishing process by straight turning. For the holder, the finishing
that we made doesn’t need to be very good because the function of holder just to join the disc brake
with the shaft.
                    MeThodology

Date                Matter             Remarks
After being given   Group meeting      Choosing the
the assignment                         product.
01/08/2006          Meeting with Mr.   Approval for the
                    Zulkepli           proposal
10/08/2006          Discussion at room Start drawing the
                    U6C 301-12         component

13/08/2006          Meeting with Mr.   1st meeting with Mr.
                    Zulkepli           Zulkepli. Asking
                                       opinion on
                                       Drawings
14/09/2006          Group Meeting      Discussion on
                                       approving the
                                       Drawing
16/09/2006          Meeting with Mr.   Asking Opinion On
                    Zulkepli           improved Drawings

20/09/2006          Group meeting at   Discuss about the
                    U6C 201-03         information that we
                                       need in presentation
22/09/2006          Meeting with Mr.   Discuss about the
                    Zulkepli           presentation. Ask
                                       anything that we
                                       don’t understand.
25/09/2006          Group meeting at   ~Improve the
                    room K11 KTR       drawing
                                       ~Start meke the
                                       presentation slide
                                       show
1/10/2006           Meeting at XA1 K15 Add information in
                                       the presentation
                                       slide show
5/10/2006           Meeting at room    ~Final edit for the
                    U6C 201-03         slide show
                                       ~ Make preparation
                                       for the presentation
                                       tomorrow
SUMMARY

       The main function of the disc brakes is to slow down a vehicle and then making it to
stop using a friction force and heat loses. In the braking system a disc brake will cooperate
with the brake calipers to halt wheel movement. Using the disc brakes in the braking
system has more advantages rather than using the drum brakes. These disc brakes offered
greater stopping performance than comparable drum brakes, including resistance to "brake
fade" caused by the overheating of brake components, and recovered quickly from
immersion (wet brakes are less effective). Unlike a drum brake, the disc brake has no self-
servo effect and the braking force is always proportional to the pedal force being applied by
the driver.

       To manufacturing the disc brakes grey cast iron is the most suitable material. The
reason in using the grey cast iron is because grey cast iron has high strength. Other than
that grey cast iron can be work at the high temperature and has good anti-friction
properties. All the properties are matching with the function and the basic working principle
of the disc brakes. When casting, grey cast iron can be free from the porosity. Grey cast
iron also a good vibration absorber and has good machinability properties. For the holder of
the disc brake the material that be used is aluminums alloy. Aluminums alloy has high
strength to weight ratio. It also has a good resistance to corrosion ease of formability and
machinability.

       To produce the disc brake the best process is the hot chamber process. In the hot chamber
process the molten metal will be forced to enter the cavity using the piston. The average pressure to
be used is 15MPa. The molten metal will be held under the pressure until it solidifies. The
passageways are built in the die to aid in rapid metal cooling. The cooling materials that be used is
water and oil. For the production of the disc brake holder the best process is the cold chamber
process. The molten metal will be poured into the injection cylinder (shot chamber). The metal is
forced into the die cavity at high pressure usually in between 20MPa to 70MPa.
 1. http://www.sme.org/cgi-bin/get-item.pl?CD638&2&SME&
 2. https://www.fkm.utm.my/~zulkepli/notes_slide.htm
 3. www.efunda.com/processes/machining/turn_types.cfm
 4. http://www.mfg.mtu.edu/marc/primers/turning/turn.html
 5. http://www.efunda.com/processes/metal_processing/die_casting.cfm
 6. http://en.wikipedia.org/wiki/Turning
 7. http://www.sfsa.org/tutorials/nadca2/TFAN06.htm
 8. http://dm.hap.com/temp.htm
 9. http://www.mini_lathe.com/Mini_lathe/Operation/Turning/turning.htm
10. http://www.diecasting.org/design/case4/HS08.htm
11. http://en.wikipedia.org/wiki/Lathe_%28tool%29
12. http://www.ballardbrass.com/gray-iron-castings.html#
13. http://www.ballardbrass.com/aluminum-castings.html

				
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