Advanced Ceramics 2

8/6/2019 Advanced Ceramics 2

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Definition

Ceramics

inorganic, nonmetallic solids

hardness, strength, low electrical conductivity,

and brittleness

Advanced Ceramics

represent an advancement over the traditional

high resistance to abrasion, excellent hot

strength, chemical inertness, high machining

speeds (as tools) and dimensional stability


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Classifications of Advanced

Ceramics Materials Oxides: Alumina, zirconia

Non-oxides: Carbides, borides, nitrides,silicides

Composites: Particulate reinforced,combinations of oxides and non-oxides.


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Categories of Ceramics

Electroceramics

Structural Ceramics

Ceramic Coatings


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Electroceramics

Electroceramic used to describe ceramic materials that have been specially

formulated for specific electrical, magnetic, or opticalproperties


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Common Applications for Electroceramics

Insulator

Resistor

High dielectric constant capacitors

Piezoelectric sonar transducers Ultrasonic transducers

Radio & communication filters

Medical diagnostic transducers

Ultrasonic motors

Electro-optic light valves

Thin-film capacitors

Ferroelectric thin-film memories


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Bulk Ceramic Thermistors

Bulk Ceramic Varistors(VDR-voltage dependentresistors)


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Bulk ceramic resistors


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Structural Ceramics

wear-resistant lightweight materials

superior to many materials with regard to stability

in high-temperature environments

remain hard and resist deformation at high

temperatures where metals soften or melt

resist cavitations and ablative wear; corrosion-

resistant inert


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Common Applications for Structural

Ceramics metal cutting

metal filters

brake pads

rotors

nozzles for water cutting

ink jet printing

rocket engines

Bioceramics Biocompatible

Flexible and durable metal oxides


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Ceramic Nozzle in Oil Wells

Fan Blades


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Ceramic Coatings

Ceramic coatings are a special film layer used

on hard materials to protect them from wear

and tear.

improved strength, hardness, elasticity, and

oxidation resistance


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Common Applications for Ceramic

Coatings

Industrial Parts

Automotive Parts


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Plasma sprayed Zirconia TitaniaYttria Ceramic Composite Coating over a Nickel Aluminium

Bond Coat

Coating sectioned from a piston ring


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Recent Developments

PSZ (partially stabilised zirconia) and phase

transformation toughening

Ron Garvie et alat the CSIRO, Melbourne

Phase transformations, alloying, quenching

and tempering techniques were applied to a

range of ceramic systems.

Significant improvements to the fracture

toughness, ductility and impact resistance of

ceramics


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Treatment of Cancer

Two methods of treatment

Hyperthermia treatment involves implanting a

bioceramic material that contains a ferrite or other

magnetic material. The area is then exposed to

alternating magnetic field, which causes the implant and

surrounding area to heat up.

Radiotherapy ,bioceramic materials can be doped with

-emitting materials and implanted into the cancerous

area


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Nanocomposite coating

manufacturing process nanocrystalline phase

amorphous phase

Nanocomposite ceramic coatings are mostly found inlaboratory instruments, surgical steel items and other

technologies that require highly specialized protection against

heat, corrosion and oxidation.

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Advanced Ceramics 2