Case Study for Applied Material Science for the Selection of materials in automobile piston

1. KUMARAGURU COLLEGE OF TECHNOLOGY
P15CCT102/ APPLIED MATERIALS ENGINEERING
Presented By,
RAGHUL (17MCC006)
GAUTHAM (17MCC007)

2. MATERIAL SELECTION
FOR
PISTON

3. PISTON:
 A piston is a cylindrical engine component that
slides back and forth in the cylinder bore by forces
produced during the combustion process.
 The piston acts as a movable end of the
combustion chamber.
 Its purpose is to transfer force from expanding
gas in the cylinder to the crankshaft via a piston
rod.

4. PISTON MATERIALS:
The most commonly used Piston
materials are
• Cast Iron
• Aluminium Alloys
Cast iron pistons are used for moderately rated
engines with piston speed below 6m/s.
Aluminium alloy pistons are used for highly
rated engines with piston speed above 6m/s.

5. CAST IRON:
 Cast iron is a group of iron-carbon alloys with a
carbon content greater than 2%.
 Carbon (C) ranging from 1.8–4 wt%, and silicon (Si)
1–3 wt% are the main alloying elements of cast
iron.
Types of Cast Iron
 Grey cast iron
 White cast iron
 Malleable cast iron
 Ductile cast iron

6. Cast Iron Characteristics:
 It is hard.
 Brittle.
 Non-malleable (i.e. it cannot be bent, stretched or
hammered into shape).
 More fusible than steel.
 Very good in compression.

7. ALUMINIUM ALLOYS:
 Aluminium alloys (or aluminum alloys) are alloys in
which aluminium (Al) is the predominant metal.
 The typical alloying elements are copper,
magnesium, manganese, silicon, tin and zinc.
 Cast aluminium alloys yield cost-effective products
due to the low melting point.

8. Aluminum Alloy Characteristics:
 High operating temperatures
 Outstanding corrosion resistance
 Lightweight
 Very good strength and hardness
 Good stiffness and strength-to-weight ratio
 Excellent EMI and RFI shielding properties
 Excellent thermal conductivity
 High electrical conductivity
 Good finishing characteristics
 Full recyclability

9. Applications for Aluminum:
 Aluminum castings improve automotive fuel
efficiency by contributing to weight saving
requirements
 Aluminum is used in a broad range of networking
and infrastructure equipment in the telecom and
computing industries because RF filter boxes and
housings require heat dissipation
 In handheld devices, aluminum castings provide
EMI/RFI shielding, rigidity, and durability with
minimal weight
 Because of aluminum’s excellent electrical
performance and shielding properties, even in high-
temperature environments, die cast aluminum is
ideal for electronic connectors and housings

10. PROPERTIES
PROPERTIES ALUMINIUM CAST IRON
Atomic Number 13 26
Crystal Structure FCC FCC
Melting Point (°C) 660.2 1204
Boiling Point (°C) 2480 2862
Mean Specific Heat (0-
100°C) (J/goC)
0.900 0.444
Thermal Conductivity (0-
100°C) (cal/cms.°C)
0.57 0.163
Electrical Resistivity at
20°C (Ω.cm)
2.69 9.61
Density (g/cm3) 2.6898 7.874
Poissons Ratio 0.34 0.29
Young's modulus 70 211
Brinell hardness 160-550 200-1180

11. Advantages of Aluminium over cast iron:
 High thermal conductivity (approx 3 times that of
cast iron
 Less variation in temperature from the crown to the
piston rings.
 Density of aluminium is about one third that of cast
iron. Therefore light weight construction and less
inertia forces.

12. CONCLUSION:
 Piston material and design contribute to the overall
durability and performance of an engine.
 Cast aluminium alloy is lightweight and has good
structural integrity and low manufacturing costs.
 The light weight of aluminium reduces the overall mass
and force necessary to initiate and maintain acceleration
of the piston.
 This allows the piston to utilize more of the force
produced by combustion to power the application.
Hence Aluminium Alloy is used for
Pistons.

13. THANK U