imperial journal of interdisciplinary research (ijir) vol ... the sae specification is j431 g3000...

Imperial Journal of Interdisciplinary Research (IJIR)

Vol-2, Issue-6, 2016

ISSN: 2454-1362, http://www.onlinejournal.in

Imperial Journal of Interdisciplinary Research (IJIR) 195

Manufacturing of Disc Brake Rotor Using

Aluminium Metal Matrix Composite

(AMMC) reinforced with Silicon Carbide

Parth S. Joshi, Kiran C. Hegade, Apoorv S. Kulkarni &

Omkar V. Karale B. E. Students, Department of Mechanical Engineering, Trinity College of Engineering and

Research, Pune, India

Abstract: This paper deals with the manufacturing of

disc brake rotor using AMMC. AMMC is the

combination of aluminium and silicon carbide along

with small quantity of other material like magnesium,

aluminium oxide, graphite which are added in precise

quantity to enhance the chemical, mechanical and

thermal strength of material. The whole process is

carried out in controlled environment. Gravity die

casting is the suitable process used for the purpose.

Pre-processing of additives are carried out precisely. Stir casting is one of the economical and extensively

used methods to enhance attractive properties of

AMC’s. This paper presents an overview of stir casing

process, process parameter and preparation of AMC

using aluminium alloy as matrix phase and alumina

(Al2O3) as reinforcement

Keywords: Aluminium Matrix Composite,

reinforcement, stir casting.

1.Introduction

Aluminium alloys are used in advanced applications

because of high strength, low density, durability,

machinability, availability and cost is very attractive

compared to competing materials. The aluminum metal

matrix composite materials is the combination of two

or more constituents in which one is matrix and other is

filler materials (reinforcements). Aluminum metal

matrix may be laminated, fibers or particulates

composites. Generally, grey cast iron is used to

manufacture brake disc rotor, but AMMC is selected

considering crucial advantages of the AMMC over cast

iron material. Disc brake used for decelerating or

stopping the automobile or to maintain a constant

velocity or to park the vehicle. This specification

dictates the correct range of hardness, chemical

composition, tensile strength and other properties

necessary for the intended use. Some racing cars and

airplanes use brakes with carbon fiber discs and carbon

fiber pads to reduce weight. In preparing metal matrix

composites by stir casting method some of the factors

that need considerable attention are as follows:

To achieve uniform distribution of the

reinforcement material

To achieve wettability between the two main

substances

To minimize porosity in the cast metal matrix

composite

1.1 Brake Disc Rotor

The Disc Brake discs are commonly manufactured

out of grey cast iron. The SAE maintains a

specification for the manufacture of grey cast 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 necessary for the

intended use. Some racing cars and airplanes use

brakes with carbon fiber discs and carbon fiber pads to

reduce weight. Wear rates tend to be high and braking

may be poor until the brake is hot. It is investigated

that the temperature distribution, the thermal

deformation and the thermal stress of automotive discs

have quiet close relations with car safety; therefore,

much research in this field has been performed.

1.2 Aluminium Metal Matrix Composite

(AMMC)

The term “composite” broadly refers to a material

system which is composed of a discrete constituent

distributed in continuous phase, and which derives its

distinguishing characteristics from the properties of

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Imperial Journal of Interdisciplinary Research (IJIR) Page 1196

constituents, from the geometry and architecture of

constituents and from properties of the boundaries

between constituents. Composite materials are usually

classified on the basis of the physical or chemical

nature of the matrix phase e.g. polymer matrix, metal-

matrix and ceramic composites. In AMCs one of the

constituents is Aluminium/ Aluminium alloy which

forms percolating network and is termed as matrix

phase. The other constituents are embedded in this

Aluminium/ Aluminium alloy matrix and serve as

reinforcement, which is usually non-metallic and

commonly ceramic such as SiC and Al2O3. The

properties of AMCs can be tailored by varying the

nature of constituents and their volume fraction.

The major advantages of AMCs compared too

unreinforced materials are as follows,

Greater strength

Improved stiffness

Reduced density (weight)

Improved high temperature properties

Controlled thermal expansion coefficient

Thermal/ heat management

Enhanced and tailored electrical performance

Improved abrasion and wear resistance

Control of mass (especially in reciprocating

applications)

Improved damping capabilities.

There has been interest in using Aluminium based

metal matrix composites for brake discs and drum

materials in recent years. While the friction and wear

of AMMCs were high speeds and loads the behavior

could be greatly improved beyond that of iron discs,

given the correct match of pad and disc material.

1.3 Reinforcement of Silicon Carbide

Silicon Carbide is the only chemical compound of

carbon and silicon. It was originally produced by a

high temperature electro-chemical reaction of sand and

carbon. Silicon carbide is an excellent abrasive and has

been produced and made into grinding wheels and

other abrasive products for over one hundred years.

Today the material has been developed into high

quality technical grade ceramic with very good

mechanical properties.

It is used in abrasives, refractoriness, ceramics and

numerous high-performance applications. The material

can also be made an electrical conductor and has

applications in resistance heating, flame igniters and

electronic components. Silicon carbide is composed of

tetrahedral of carbon and silicon atoms with strong

bonds in crystal lattice. This produces a very hard and

strong material.

The properties of silicon carbide are described as

follows. Mechanically, silicon carbide has low density,

high strength, high hardness as well as high elastic

modulus. Thermal properties of silicon carbide are also

excellent as it has low thermal expansion, high thermal

conductivity and excellent thermal shock resistance.

Also it has superior chemical inertness.

As silicon carbide is added in the AMMC as a

reinforcement, it also reinforces the overall properties

of the AMMC. It improves the mechanical properties

of the AMMC, it increases the strength and hardness of

the composite. And also it improves the thermal

conductivity and thermal shock resistance of the

material.

2. Processing of AMMC’s:

Primary process for manufacturing of AMMC’s at

industrial scale can be classified into two main groups.

1) Liquid state processes:

a) Stir casting b) Infiltration process c) Reactive

processing d) Spray deposition

2) Solid state processes:

a) PM processing b) Diffusion bonding c) Physical

vapour deposition.

2.1 Stir casting:

Stir casting is a process in which uniformly mixed very

fine powder of additives are mixed with a molten

matrix metal by means of mechanical stirring. Stir

casting is the simplest and the most cost effective

method of liquid state fabrication. The liquid

composite material is then cast by conventional casting

methods and may also be processed by conventional

Metal forming technologies.

a. Stirrer

It is very important parameter in stir casting process

which is required for vortex formation. The blade angle

and number of blades decides the flow pattern of the

liquid metal. The stirrer is immersed till two third

depth of molten metal. All these are required for

uniform distribution of reinforcement in liquid metal,

perfect interface bonding and to avoid clustering.

Stirring speed decides formation of vortex which is

responsible for dispersion of particulates in liquid

metal. In our project stirring speed is 300







rpm.

Figure 1. Stir Casting Process

b. Pre-Heating of Reinforcements:

Casting process is very difficult if reinforcement

particles are wet, also it results in non-uniform

distribution and poor mechanical property. To avoid

this problem, reinforcements are pre-heated at 500°C

for 40 minutes.

c. Pre-Heating of Mould:

Porosity is the major problem in casting. In order to

avoid porosity preheating of mould is good solution. It

helps in removing the entrapped gases from the slurry

to go into the mould. It also enhances the mechanical

properties of the cast AMC. Mold is heated to 500°C

for one hour.

2.2 Preparation of Patterns design and

pattern:

In this step we have prepared patterns of

aluminium.

Figure 2. Pattern Dimensions

Figure 3. Casting Dimensions

Figure 4. Aluminium Pattern

2.3 Mould Making Process:

In this step we have prepared mould for casting

specimen of various mechanical tests like tensile test,

hardness test, torsion test, etc. In order to avoid

porosity preheating of mould is good solution. It helps

in removing the entrapped gases from the slurry to go







into the mould. It also enhances the mechanical

properties of the cast AMC. Mold is heated to 500°C

for one hour.

Figure 5. Cope of the mould

Figure 6. Drag of the mould

2.4 Preparation of reinforcement:

Precise quantity of reinforcements is weighted and

collected in crucible for moulding the composition of

AMMC is given below:

Aluminium Oxide (Al2O3): 1%

Silicon Carbide (SiC): 3%

Graphite: 2.5%

Magnesium (Mg): 1.5%

Aluminium (Al): 92%

Figure 7. Graphite Powder

Figure 8. silicon carbide powder

Figure 9. Aluminium Oxide Powder







Figure 10. Magnesium Powder

3. Preparation of aluminum based metal

matrix composite (AMMC):

Aluminium alloy is cleaned to remove dust

particles, weighed and charged in the crucible for

melting. Now reinforcement powder and magnesium

powder are weighed on the weighing machine, they are

pre heated for 45 minutes at a temperature 500. When

matrix was in the semisolid stage condition at 650°C, 1

% by weight of pure magnesium powder is used as

wetting agent. Heater temperature is then increased to

800oC. At this heater temperature stirring is started and

continued for five minutes. Stirring rpm is gradually

increased from 0 to 300 RPM with the help of speed

controller. Preheated reinforcements are added during

five minutes of stirring. Reinforcements are poured

manually with the help of conical hopper. Stirrer rpm is

then gradually lowered to the zero. Then molten

composite slurry is poured in mould without giving

time for reinforcement to settle down at crucible

bottom. Mould is preheated at 500°C temperature for

one hour before pouring the molten slurry in the

mould. This is necessary to maintain slurry in molten

condition throughout the pouring. Mould is then

allowed to cool and after cooling runner, riser are

removed from disc. Final finishing is done using lathe

machine to achieve dimensional accuracy.

Figure 11. Furnace

Figure 12. Pouring of slurry

Figure 13. Machining of disc







Figure 14. Final finished disc

4. Conclusion:

Following conclusion is drawn from above paper:

1. Gravity stir casting is most economical

process used for casting of AMMC.

2. Pre heating of mould reduces porosity and

enhances mechanical properties.

3. Pre heating of reinforcement results in

uniform distribution and better mechanical

properties.

4. Addition of Magnesium is important to

increase wettability.

6. References

[1] Bharath V, Madev Nagaral, V Auradi and S. A.

Kori. (2014). Preparation of 6061Al- Al2O3 MMC’s by

Stir Casting and Evaluation of Mechanical and Wear

Properties. Procedia Materials Science 6, 1658 –

1667.

[2] M K SURAPPA. (February/April 2003).

Aluminium matrix composites: Challenges and

opportunities. Sadhana Vol. 28, Parts 1 & 2, pp. 319–

334.

[3] Shriyash S. Shinde, S. G. Kulkarni, S. S. Kulkarni

(2015). Manufacturing Of Aluminium Matrix

Composite Using Stir Casting Method. [IJIERT] ISSN:

2394-3696 VOLUME 2, ISSUE 5, MAY-2015

[4] Muhammad Hayat Jokhio, Muhammad Ibrahim

Panhwar And Mukhtiar Ali Unar. Manufacturing Of

Aluminum Composite Material Using Stir Casting

Process. Mehran University Research Journal Of

Engineering & Technology, Volume 30, No. 1,

January, 2011 [Issn 0254-7821]

[5] Ajay Singh, Love Kumar, Mohit Chaudhary, Om

Narayan, Pallavsharma, Piyush Singh, Bhaskar

Chandra Kandpal, Som Ashutosh. MANUFACTURING

OF AMMCS USING STIR CASTING PROCESS AND

TESTING ITS MECHANICAL PROPERTIES Kandpal,

Et Al., International Journal Of Advanced Engineering

Technology E-ISSN 0976-3945

[6] R.Kumar, J.Jegan, L.Initha, Processing Of

Aluminium Metal Matrix Composites (Ammc) Through

Stir Casting Route. IJME Volume 2, Issue 12,

December 2014.

[7] Rajeshkumar Gangaram Bhandare, Parshuram M.

Sonawane. (December 2013). Preparation of

Aluminium Matrix Composite by Using Stir Casting

Method. International Journal of Engineering and

Advanced Technology, Volume-3, Issue-2.

[8] Karnik Madhuri G., Sonawane Parushuram M.,

Kulkarni Swanand R., “Effect of graphite addition on

the mechanical properties of stir cast particulate

aluminium metal matrix composite reinforced with

alumina and silicon carbide.”, International

Conference on Design, Manufacturing and

Mechatronics 2014.



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