Review on
Carbotanium
Aditya Chandurkar
Outline
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Objective
Titanium processing
Carbon fibre
Titanium Carbon fibre bonding
Applications
Future Work
Objective
• Smart material
• How it can be made
• Where can it be applied
Titanium
• Titanium is named after the Titans, the powerful sons of the
earth in Greek mythology.
• Titanium is the forth abundant metal on earth crust (~ 0.86%)
after aluminum, iron and magnesium.
• Have similar strength as steel but with a weight nearly half of
steel.
• Not found in its free, pure metal form in nature but as oxides,
i.e., ilmenite (FeTiO3) and rutile (TiO2)
Production of Titanium alloys
• Extraction process – Kroll
process
• Melting Process
ESR
VAR
EBM
PAM
Induction Skull Melting
• Casting process – Investment
Casting, laser fabrication
• Forming Process – rolling,
extrusion, forging
• Heat treatment
Physical Properties of TI
Crystal Structure HCP (below 882.5 C)
BCC (above 882.5 C)
Atomic diameter
0.320
Density
4.54 g. cm-3
Melting Point
1667
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Experiences allotropic transformation (α-> β) at 882.5 C
Highly react with oxygen, nitrogen, carbon and hydrogen
Difficult to extract -> expensive
High strength and toughness
Used mainly in wrought forms for advanced applications
where cost is not critical
Classification of TI alloys
• Commercially pure (CP) titanium alpha and near alpha titanium
alloys
• Alpha-beta titanium alloys
• Beta titanium alloys
Different crystal structures and properties allow manipulation of heat
treatments to produce different types of alloy microstructures to suit
the required mechanical properties.
Beta Ti alloys
• Beta stabilizers are sufficiently added to retain a fully β structure (avoid
martensite formation) when quenched from the β phase field
Metastable β alloys : Mo Eq. <25
Stable β alloys : Mo Eq. 25-40
Beta titanium alloys
• β titanium alloys possess a BCC crystal structure, which is readily coldworked (than HCP α structure) in the β phase field
• Microstructure after quenching contains equiaxed β phase
• After solution heat treating + quenching giving very high strength (up
to 1300-1400 MPa)
• Metastable β Ti alloys are hardenable while stable β Ti
alloys are non-hardenable
Composition and applications of
β titanium alloys
Beta alloys
Advantages
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High strength to density ratio
Low modulus
High strength/high toughness
High fatigue strength
Good deep hardenability
Low forging temperature
Strip producible
Cold formable
Easy to heat
Excellent corrosion resistance
Excellent combustion resistance
Disadvantages
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High density
Low modulus
Poor low high temperature properties
Small processing window
High formulation cost
High springback
Microstructural instabilities
Interstitial pick up
Carbon fibre
• Collection of thin stand of material mostly composed of carbon atoms.
• The carbon atoms are bonded together in microscopic crystals that are
more or less aligned parallel to the long axis of the fiber.
• The crystal alignment makes the fiber incredibly strong for its size.
Several thousand carbon fibers are twisted together to form a yarn,
which may be used by itself or woven into a fabric
• The fabric is combined with epoxy is molded into shape to form various
composite material
Classification of Carbon Fiber
• Carbon fibers are classified by the tensile modulus of the fiber.
• Tensile modulus is a measure of how much pulling force a certain
diameter fiber can exert without breaking
• Ultra-high-modulus (modulus >450Gpa)
• High modulus (modulus between 350-450Gpa)
• Intermediate Modulus (modulus between 200-350Gpa)
• Low Modulus and high tensile (modulus < 100Gpa, tensile strength >
3.0Gpa)
• Super high tensile (tensile strength > 4.5Gpa)
Raw Materials
• 90% of the carbon fibers produced are made from polyacrylonitrile
• remaining 10% are made from rayon or petroleum pitch
• All of these materials are organic polymers, characterized by long
strings of molecules bound together by carbon atoms
The Manufacturing
Process
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Part Chemical and Part Mechanical
Spinning
Stabilizing
Carbonizing
Treating the surface
Sizing
Carbon-Fiber
• Advantages
• Very low weight
• High impact tolerance
• Insensitive to
temperature
• Reduced maintenance
costs
• Long service life
Disadvantages
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Oxidize readily between 600-700 C
Very Expensive
Complicated to produce
High electrical conductivity of
graphite particles
Ti-Carbon Fibre Bonding
• Using Adhesive
• Ion bean enhanced deposition
Applications
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Defense applications such as tank shields, Fighter plans.
Aerospace applications
Aircraft Applications
Automotive applications
Future work
• Captain America’s Shield
• Wolverines Claw
• Body Armour
Questions