Upload
xaad-arif
View
143
Download
1
Embed Size (px)
Citation preview
MOIZ ULLAH BAIG (MM-036)
SAAD ARIF (MM-026)
HARIS IQBAL KHAN (MM-020)
OMAR SIDDIQI (MM-004)
Department of Materials Engineering
GLASS
INTRODUCTION
The presence of glasses in our
everyday environment is so common
that we rarely notice their existence.
A glass can be defined as an
amorphous solid completely
lacking in long range, periodic
atomic structure, and exhibiting a
region of glass transformation
behavior.
HARDNESSThe Vickers hardness of oxide glasses
ranges from 2 to 8 Gpa.
In general, the effects of glass composition on hardness parallel those found
for elastic modulus.
FATIGUE
Static fatigue, is due to interaction of the glass with the surrounding atmosphere, resulting in crack growth under constant load.
A higher failure strength is observed when the load is increased rapidly, since this effect is observed under conditions of changing load, it is often called dynamic fatigue.
REFRACTIVE INDEX
The refractive index remains the most measured optical property
of glasses, as well as the most basic optical property for
determination of the appropriate glass for many applications.
Example; optical fibers
DISPERSION
The variation in index with wavelength is known as dispersion.
It is more convenient to measure the refractive index at a few specified wavelengths, and use these measurements as the basis for terms which can be used to compare the dispersion of different glasses.
ADVANCETECHNIQUES
The advent of the age of technology created many new opportunities for the application of glasses.
GLASS FIBERSFiberglass are widely used for thermal insulation, fire resistant textiles, and reinforcing fibers for composites.
Insulation fibers are produced from modified soda-lime-silica compositions, which contain more alumina and iron than container glasses.
Fiberglass is produced from E glass, which actually includes a range of alkaline earth aluminoborosilicate compositions.
Nanostructure Thin Films of Titanium Dioxide Coated on Glass
Prevent from Escherichia coli and Staphylococcus aureus
Escherichia coli > Food poisoningStaphylococcus aureus > Skin infection
SMART
GLASSSmart Glass or Switchable Glass is a product
of cutting-edge technology that allows users
to block either all light or just some by simply
turning a knob or pressing a button.
This type of light control could potentially
save tremendously on heating, cooling and
lighting costs.
BULK METALLIC
GLASSA new class of metallic alloys with a unique
amorphous atomic structure.
The amorphous atomic structure provides very high
yield strength and very high elastic limit (HEL) under
shock impact conditions.
This also provides an opportunity to make
various composites with tailored properties for
specific applications.
Transmission Electron Microscope micrograph showing the amorphous atomic structure of BMG (on the right) versus crystalline atomic structure of a typical metal (on the left). (Magnification ~X 5 Millions)
Striking face plate in golf clubs, frame in tennis rackets, various shapes of optical mirrors, casing in cellular phones, casing in electro-magnetic instruments, electro-magnetic shielding plates, high torque geared motor parts , high corrosion resistant parts.