Group 1: Lucky Buğra
Crankshaft
Güçlü Yardımcı
Fatih Cemal Ülgen
Ali Buğra Basan
&
Güncel Kırlangıç
What is a Crankshaft?
• The engine part that turns the
linear motion of the piston
into rotational motion.
• It is essential for every type
of Internal Combustion
Engine.
• Varient sizes of crankshafts
are avalible in cars,
helicopters, cruise ships.
Brief History of Crankshaft
• Firstly used in a Roman sawmill in
3rd century.
• Used to turn circular motion into
linear motion.
• In 15th century, they are used in
paddle-wheel boats.
• Also used in the studies of Leonardo
da Vinci.
• Gained importance after industrial
revolution.
• Used in every internal combustion
engine today.
Requirements
• It has to endure high amount of
torsional and bending stresses.
• It should have high resilience and
fatigue resistence to prevent
deformation.
• It needs to have an endurance limit
since it has to endure many cycles.
• It should also have a low density so that
the vehicle will have a better
performance.
• It should have a high wear resistence
and surface hardness to prevent surface
cracks.
Material Selection
Currently Used Materials
• The main materials used in
crankshaft manufacturing are steel
alloys.
• The plain carbon alloys such as AISI
1010, 1045, and 1053 are widely
used in low-power engine
crankshafts.
• For high-power engines, trucks or
racing cars, AISI 5140, 4130, and
4340 are used.
• Arrow Precision, uses 722M24 or
other commercially available
aerospace grade steels.
• The French manufacturer
Aubert&Duval uses 32-CrMoV-13.
Properties of currently used materials
Overall;
• Stiffness
• Torsional and Bending
Strength
• Fatigue strength
• Hardness
• Resilience are the main
properties that affect the
crankshaft life and/or quality.
AISI 1010 CARBON STEEL
Element
Content (%)
Iron, Fe
99.18-99.62 %
Manganese, Mn
0.30-0.60 %
Sulfur, S
≤0.050 %
Phosphorous, P
≤0.040 %
Carbon, C
0.080-0.13 %
Properties
Metric
Tensile strength
365 MPa
Yield strength (depending on temper)
305 MPa
Elastic modulus
190-210 Gpa
Hardness, Rockwell B (converted from
Brinell hardness)
60
AISI 4340
Element
Content (%)
Iron, Fe
95.195 - 96.33
Nickel, Ni
1.65 - 2.00
Chromium, Cr
0.700 - 0.900
Manganese, Mn
0.600 - 0.800
Carbon, C
0.370 - 0.430
Molybdenum, Mo
0.200 - 0.300
Silicon, Si
0.150 - 0.300
Sulfur, S
0.0400
Phosphorous, P
0.0350
Properties
Metric
Tensile strength
745 MPa
Yield strength
470 MPa
Elastic modulus
190-210 GPa
Hardness, Rockwell B (converted from Brinell
hardness)
95
Problems encountered in current
materials
• Crack formation, bending of the
crankshaft, and surface damage due to
friction.
• There are many causes but most important
ones are;
- Loss of effective lubrication
- Faulty crankshaft damper or detuner
- Bearing misalignment
- Overloading of engine
- Failure due to fatigue
New Material Options
• Carbon Fiber Reinforced Polymer has perfect properties
although complex shapes cannot be created.
• CentrAL (Central Reinforced Aluminum) is also a good choice
although it has to be manufactured with powder metallurgy
which is not a feasible method for crankshaft production.
• SiCp Particulated Aluminum Alloy is the solution since it is
lightweight, has better properties than AISI 4340, and can be
produced by casting.
Our Solution:
SiCp Particulated Aluminum Alloy
+
=
SiCp Particulated Aluminum Alloy
SiCp Particulated Aluminum Alloy
Matrix
AI-UTN15 with SiCp Particles
• Very high yield strength (Expected value is around 1000
Mpa)
• Much lighter then High Strength Steels (density of AISI
4340 is 7.85 g/cm3 our material is 2.88 g/cm3 )
• High fatigue strength (Expected fatigue strength is higher
then AISI 4340)
• High resilience
Manufacturing Process
Currently Used Processes
• Casting: Green mold casting and shell mold casting.
Lower strength product, cheap process.
• Forging: Machining required after forging.
Cheaper in mass production.
• Machining: Directly machined to final shape from billet.
Best dimensional accuracy and design flexibility.
Low production rate and costly.
• Heat treatments and surface treatments are available for all the
manufacturing processes.
Alternative Processes
• Powder Metallurgy: Problems due to part shape.
Part can’t be divided into male and female molds.
• Die Casting: High tooling cost and complicates heat treatment.
• Carbon Fiber Molding: Molding problems due to crankshaft shape.
Our Manufacturing Process
• Atomization:
Silicon Carbide particles are manufactured by atomization.
High pressure air is sprayed to liquid SiC which is poured through
a small orifice.
SiC particle size is controlled by the air pressure and filter.
• Mixing:
SiC particles are mixed to the molten aluminum and the mixture
is stirred for a homogenous structure. Since the melting T of SiC
is much higher than aluminum, it does not change phase.
• Casting:
Aluminum has to be molten to mix with SiC particles. Since the
aluminum has molten, casting is the best option for
manufacturing.
Shell mold casting is preferred for better surface finish and
dimensional tolerances than sand casting.
• Heat Treatement:
After the part is removed from the mold, T7 heat treatement is
applied. Stabilization of the material will prevent long term
strength drops.
• Surface Treatment:
Fillet rolling rounds up and smoothens the pin and main fillets.
Compressive residual stresses improve fatigue strength.
• Anodizing:
Aluminum hard coat anodizing provides a smooth, hard,
corrosion resistant and wear resistant surface. In this process,
part is dipped into acid bath and an uniform aluminum oxide
layer is formed on the surface. Thickness depends on the waiting
time.
QUALITY CONTROL AND TESTING
Main Topics
• Chemical analysis for the material
– X-ray fluorescence (XRF)
– X-ray photoelectron spectroscopy (XPS)
– Scanning electron microscopy (SEM)
• Quality control of the part with mechanical testing
– Fatigue test
– Bending test
• Forming inspection
– Dimension control
– Heat treatment control
• Hardness test
• Conductivity test
• Non-destructive testing
– Liquid penetrant
– Radiography
Chemical Analysis
• X-ray fluorescence (XRF): It is the emission of
characteristic "secondary" (or fluorescent) X-rays
from a material that has been excited by bombarding
with high-energy X-rays or gamma rays.
• It will be used in the examination of composition and
impurity percentage.
Chemical Analysis
• X-ray photoelectron spectroscopy (XPS): It is a
surface-sensitive quantitative spectroscopic
technique that measures the elemental composition
at the parts per thousand range, empirical formula,
chemical state and electronic state of the elements
that exist within a material.
• Since we can measure the uniformity of a chemical
composition, with this method, we will be able to see
the homogeneity of the matrix - particle mixture.
Chemical Analysis
Scanning electron
microscope (SEM):
• It is a type of electron
microscope that produces
images of a sample by
scanning it with a focused
beam of electrons.
• Thermionic emission with
lanthanum hexaboride.
Chemical Analysis
• Images will be used for
measuring the particle
size.
• Volume percentage of
silicon carbide by
Clemex Image
Analyzing Program.
Quality Control with Mechanical
Testing
Fatigue Test
• Fatigue is the weakening
of a material caused by
cyclic loading.
• If our part's fatigue
strength is resistant
enough for an
automotive engine to
withstand the cyclic
loads.
Quality Control with Mechanical
Testing
Bending Test
• Crankshaft undergoes a lot of bending stress caused by the connecting rod.
• This test will be carried out to see the part's bending strength, and if it is high
enough for a crankshaft.
Forming Inspection
Dimension Control
• Comparison between the
part and its 2D/3D
model.
• Can be measured
manually with tools.
• Dimensional stability by
placing onto exact scaled
blueprints.
Forming Inspection
Heat Treatment Control
• Microstructural changes
• Hardness and conductivity tests
• Tabulated hardness and conductivity ranges
Forming Inspection
Conductivity Test
• Conductivity value relative to the copper’s
conductivity
• Default value is 8.2, pure copper’s conductivity is
100.
• Calibration is important.
Forming Inspection
Hardness Test
• Hardness is the resistance to
permanent indentation.
• Rockwell Hardness Test will be
conducted.
• Diamond cone for hard
materials, steel ball for soft
materials.
Non-Destructive Testing
Liquid Penetrant
• Inspection of surface cracks
• The part is dipped into liquid penetrant, cleaned, and
inspected under blacklight.
Non-Destructive Testing
Radiography
• To determine the interior cracks and porosities
• Alpha and/or gamma rays
Summary
• SiC particulated aluminum alloy is the new
material for crankshaft.
• Particle manufacturing method is atomization.
• The part’s manufacturing process is casting.
• Heat treatment, fillet rounding, and anodizing
are after processes.
• Chemical analysis, mechanical tests, forming
inspections, and non-destructive testing
methods are conducted for quality control.
THANK YOU FOR LISTENING