Titanium Alloy

1
Titanium Alloy

• Titanium and its alloys have proven to be
  technically superior and cost-effective materials
  of construction for a wide variety of aerospace,
  industrial, marine and medical applications.
• In North America, approximately 70 of the
  titanium consumed is utilized for aerospace
  applications.
• Due to the expansion of existing applications and
  the development of new uses, the greatest growth
  will occur in the industrial, marine and
  commercial sectors.

2
Titanium Alloy

• Titanium is a white metal, and has the best
  strength to weight ratio among the metals.
• Titanium is very reactive, and because of this it
  is often used for alloying and deoxidizing other
  metals.
• Titanium is a more powerful deoxidizer of steel
  than silicon or manganese.

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Titanium Alloy

• Titanium is 40 lighter than steel and 60
  heavier than aluminum.
• This combination of high strength and low weight
  makes titanium a very useful structural metal.
• Titanium also features excellent corrosion
  resistance, which stems from a thin oxide surface
  film which protects it from atmospheric and ocean
  conditions as well as a wide variety of
  chemicals.

4
Titanium Alloy Grade

• There are five grades of what is known as
  commercially pure or unalloyed titanium, ASTM
  Grades 1 through 4, and 7.
• Each grade has a different amount of impurity
  content, with Grade 1 being the most pure.
• Tensile strengths vary from 172 MPa for Grade 1
  to 483 MPa for Grade 4.

5
Titanium Alpha Alloy

• Titanium alpha alloys are alloys that typically
  contain aluminum and tin, though they can also
  contain molybdenum, zirconium, nitrogen,
  vanadium, columbium, tantalum, and silicon.
• Alpha alloys do not generally respond to heat
  treatment, but they are weldable and are commonly
  used for cryogenic applications, airplane parts,
  and chemical processing equipment.

6
Titanium Alpha-Beta Alloy

• Alpha-beta alloys can be strengthened by heat
  treatment and aging, and therefore can undergo
  manufacturing while the material is still
  ductile, then undergo heat treatment to
  strengthen the material, which is a big
  advantage.
• The alloys are used in aircraft and aircraft
  turbine parts, chemical processing equipment,
  marine hardware, and prosthetic devices.

7
Titanium Alpha-Beta Alloy

• The smallest group of titanium alloys, beta
  alloys have good hardenability, good cold
  formability when they are solution-treated, and
  high strength when they are aged.
• Beta alloys are slightly more dense than other
  titanium alloys, having densities ranging from
  4840 to 5060 kg/m3.
• They are the least creep resistant alloys, they
  are weldable, and can have yield strengths up to
  1345 MPa.
• They are used for heavier duty purposes on
  aircraft.

8
Titanium Alloy Implants

• Market
• Titanium is a standard material for medical
  devices such as hip joints, bone screws, knee
  joints, bone plates, dental implants, surgical
  devices, pacemaker cases and centrifuges due to
  its total resistance to attack by body fluids,
  high strength and low modulus.

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Titanium Alloy Implants

• Metal of choice
• The body readily accepts titanium since it is
  more biocompatible than stainless steel or cobalt
  chrome. Titanium also has a higher fatigue
  strength than many other metals. The unique
  qualities of titanium prove to be MRI (Magnetic
  Resonance Imaging ) and CT (Computed Tomography )
  compatible.

10
Titanium Alloy Implants

• Machinability
• The machinability of titanium is comparable to
  most stainless steels and better than cobalt
  chrome. Sharp, clean tools with good chip removal
  and ample coolant are recommended when Drilling,
  Turning, Milling or Cold Sawing titanium. The
  work hardening rate for titanium is less than
  stainless steel.

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Titanium Alloy Implants

• Medical Specifications for Titanium Alloy
• ASTM F-67-68(94)E1
• Unalloyed titanium for surgical implant
  applications.
• ASTM F-136-92E1
• Wrought titanium 6Al-4V ELi Alloy for surgical
  implant applications
• ASTM F 1472-93
• Wrought titanium 6Al-4V Alloy for surgical
  implant applications.

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Titanium in Medical Applications

• Bone and Joint Replacement
• About one million patients worldwide are treated
  annually for total replacement of arthritic hips
  and knee joints.
• The prostheses come in many shapes and sizes.
• Hip joints normally have a metallic femoral stem
  and head which locates into an ultrahigh
  molecular weight low friction polyethylene
  socket, both secured in position with polymethyl
  methacrylate bone cement.

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Titanium in Medical Applications

• Bone and Joint Replacement
• Some designs, including cementless joints, use
  roughened bioactive surfaces (including
  hydroxyapatite) to stimulate osseointegration,
  limit resorption and thus increase the implant
  lifetime for younger recipients.
• Internal and external bone-fracture fixation
  provides a further major application for titanium
  as spinal fusion devices, pins, bone-plates,
  screws, intramedullary nails, and external
  fixators.

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Titanium in Medical Applications

• Dental Implants
• A major change in restorative dental practice
  worldwide has been possible through the use of
  titanium implants.
• A titanium 'root' is introduced into the jaw bone
  with time subsequently allowed for
  osseointegration.
• The superstructure of the tooth is then built
  onto the implant to give an effective replacement.

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Titanium in Medical Applications

• Cardiovascular devices
• Titanium is regularly used for pacemaker cases
  and defibrillators, as the carrier structure for
  replacement heart valves, and for intra-vascular
  stents.

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Titanium in Medical Applications

• External Prostheses
• Titanium is suitable for both temporary and long
  term external fixations and devices as well as
  for orthotic calipers and artificial limbs, both
  of which use titanium extensively for its light
  weight, toughness and corrosion resistance.

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Titanium in Medical Applications

• Surgical Instruments
• A wide range of surgical instruments are made in
  titanium.
• The metal's lightness is a positive aid to
  reducing any fatigue of the surgeon.
• Instruments are frequently anodised to provide a
  non reflecting surface, essential in
  microsurgical operations, for example in eye
  surgery.
• Titanium instruments withstand repeat
  sterilisation without compromise to edge or
  surface quality, corrosion resistance or
  strength.
• Titanium is non magnetic, and there is therefore
  no threat of damage to small and sensitive
  implanted electronic devices.