HIGH PERFORMANCE MATERIALS

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HIGH PERFORMANCE MATERIALS
Developments
1926- 1990 Synthetic rubber. Polyvinyl
chloride (PVC). New molding and extrusion
techniques for plastics. Polystyrene.
Polyethelene. continuous casting of steel,
Plexiglass. Nylon in 1938. Teflon discovered by
Roy Plunkett. Fiberglass. Foam glass insulating
material. Plastic contact lens. Vinyl floor
covering. Aluminum-based metallic yard. Ceramic
magnets. Basic oxygen process to refine steel
making. Karl Zeigler invents new process for
producing polyethelene. Dacron, plasticized PVC,
and silicones manufactured by Dow Corning.
Polypropylene (petroleum-based). Superpolymers
(heat resistant). 1964 - Acrylic paint . Carbon
fiber (used to reinforce materials in high
temperature environment). Beryllium (hard metal)
developed for heat shields in spacecraft, animal
surgery, aircraft parts, etc. Sialon (ceramic
material for high-speed cutting tools in metal
machining). Soft bifocal contact lens in 1983.
Synthetic skin.
New composites and lightweight steel
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• SMART MATERIALS- which adjust to the requirements
• "smart materials" also called intelligent
  materials or active materials describes a group
  of material systems with unique properties.
• The technological field of smart materials is
  not transparent or clearly structured. It has
  evolved over the past decades with increasing
  pace during the 1990s to become what it is today.
• Smart materials, Intelligent Materials, Active
  Materials, Adaptive Materials and to some extent
  actuators and sensors are almost always used
  interchangeably.
• Active materials - two groups.
• 1. The classical active materials as
  viewed by the academic community and is
  characterized by the type of response these
  materials generate.
• 2. Consists of materials that respond to
  stimuli with a change in a key material property,
  eg.electrical conductivity or viscosity
• Mention of medicines, packed items which will
  indicate the life with change in time,
  environment, decay etc dress materials which
  will adjust with the human conditions etc. etc.

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Smart Materials
Also termed as Responsive Materials

• "Smart" materials respond to environmental
  stimuli with particular changes in some
  variables. Also called responsive materials.
  Depending on changes in some external
  conditions, "smart" materials change either their
  properties (mechanical, electrical, appearance),
  their structure or composition, or their
  functions. Mostly, "smart" materials are
  embedded in systems whose inherent properties can
  be favorably changed to meet performance needs.

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Smart Materials
Colour changing materials Light emitting Materials Moving materials Photochromic materialsThermochromic materials Electroluminescent materialsFluorescent materialsPhosphorescent materials Conducting polymersDielectric elastomersPiezoelectric materialsPolymer gelsShape memory alloys (SMA)
A smart material with variable viscosity may turn
from a fluid which flows easily to a solid. A
smart fluid developed in labs at the Michigan
Institute of Technology
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• Self diagnostic materials
• Optic fibres composite Smart
  composites Smart tagged composites
• Temperature changing materials
• Thermoelectric materials
• Thickness changing fluids
• Magneto-Rehological fluids (MRFs)
• References
• Intelligent MaterialsSmart materials workshop

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Piezoelectric Materials
1. When a piezoelectric material is deformed, it
gives off a small but measurable electrical
discharge
2. When an electrical current is passed through a
piezoelectric material it experiences a
significant increase in size (up to a 4 change
in volume)
Most widely used as sensors in different
environments
To measure fluid compositions, fluid density,
fluid viscosity, or the force of an impact
Eg Airbag sensor in modern cars-
senses the force of an impact on the car and
sends and electric charge deploying the airbag.
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Electro-Rheostatic (ER) and Magneto-Rheostatic
(MR) materials
These materials are fluids, which can experience
a dramatic change in their viscosity
Can change from a thick fluid (similar to motor
oil) to nearly a solid substance within the span
of a millisecond when exposed to a magnetic or
electric field the effect can be completely
reversed just as quickly when the field is
removed.
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Shape Memory Alloys (SMA)

• Shape memory alloys (SMA's) are metals, which
  exhibit two very unique properties,
  pseudo-elasticity, and the shape memory effect.
  Arne Olander first observed these unusual
  properties in 1938 (Oksuta and Wayman 1938), but
  not until the 1960's were any serious research
  advances made in the field of shape memory
  alloys. The most effective and widely used alloys
  include NiTi (Nickel - Titanium), CuZnAl, and
  CuAlNi

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Applications of Shape Memory Alloys

• Aeronautical Applications
• Surgical Tools
• Muscle Wires

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How Shape Memory Alloys Work
The Martensite and Austenite phases
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Microscopic and Macroscopic Views of the Two
Phases of Shape Memory Alloys
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The Dependency of Phase Change Temperature on
Loading
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Microscopic Diagram of the Shape Memory Effect
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Ferromagnetic Shape Memory Alloys (FSMA)

• Ferromagnetic Shape Memory Alloys (FSMA) Recently
  discovered class of actuator material,
  Magnetically driven actuation (field intensity
  varies, about 3KG and larger) and
• large strains (around 6).
• FSMA are still in the development phase
• Alloys in the Ni-Mn-Ga ternary.
• FSMAs are ferromagnetic alloys which also support
  the shape memory effect.

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SHAPE MEMORY EFFECT

• Implemented in
• Coffee pots
• The space shuttle
• Thermostats
• Vascular Stets
• Hydraulic Fittings (for Airplanes)

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Pseudo-elasticity
Applications in which pseudo-elasticity is used
are Eyeglass Frames Bra, Under wears Medical
Tools Cellular Phone Antennae Orthodontic
Arches
Load Diagram of the pseudo-elastic effect
Occurring
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Advantages and Disadvantages of SMAs

• Bio-compatibility
• Diverse Fields of Application
• Good Mechanical Properties (strong, corrosion
  resistant)

Relatively expensive to manufacture and machine.
Most SMA's have poor fatigue properties this
means that while under the same loading
conditions (i.e. twisting, bending, compressing)
a steel component may survive for more than one
hundred times more cycles than an SMA element
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• ABOUT
• METALLIC COATINGS
• DIFFUSION COATINGS
• ANODISING
• POWDER COATING
• THERMOPLASTICS
• THERMOSETTING PLASTICS
• ELASTOMERS printouts shall be supplied