DEVELOPMENT OF LOW TEMPERATURE GLASS CERAMIC FROM LOCAL RAW MATERIALS
DEVELOPMENT OF LOW TEMPERATURE GLASS CERAMIC FROM LOCAL RAW MATERIALS
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Date
2008-12
Authors
ALI, EDWIN ADOYI
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Abstract
Glass ceramics, a new family of polycrystalline materials produced by the controlled
crystallization of glass has many uses cutting across all spheres of life from domestic appliances
through medical devices to space exploration. The production process, just like that of other
pyrotechnic products, takes a high toll on energy demand as a high temperature process. The best
example can be drawn from the US economy where the annual energy bill for the glass industry as
a multibillion-dollar industry is put at more than 1.3 billion USD.
In the present study, an attempt is made to find alternative route for ceramic glass production in
the Nigeria that is cost effective in terms of energy input. In the process, a novel route outside the
two usual routes employed in glass ceramic production was adopted in fabricating a product
which when subjected to some physical tests showed every attribute of glass ceramics. Although
the process, which involved the sintering crystallization of glass and crystalline composites, has
no preference to any particular glass composition or crystalline material, a low melting glass
composition was used in the experiment to situate the process within the many limitations of the
experiment. In this case an ophthalmic glass composition was selected, partially melted at
1200oC, fritted and remixed with a fresh batch and sintered at 1000oC. The percentage water
absorption, porosity bulk density and specific gravity were evaluated using by the Archimedes’
Principle (ASTM C373). The evaluation of these properties has a direct bearing to the ultimate
characteristics of the glass-ceramic product.
The values obtained were 0.176 % for water absorption, 0.268% for porosity, 1.528 for specific
gravity and 1.53gcm-3 for density. The density is indicative of a lightweight material relative to
the properties of the derivative materials. The XRD analysis shows the main crystalline phase in
the material to be cristobalite and nephline. Optical microscopy obtained confirmed the presence
of crystalline phases in a glassy matrix, which is conclusive of the fact that the product is indeed
glass ceramic.
With further improvement the product of the experiment is a candidate for application as an
electronic spacer as a lightweight material. However if substitute can be found for the Pb content,
which is considered a toxic substance, its future use will extend to utility objects.
Description
A DISSERTATION SUBMITTED TO THE POSTGRADUATE SCHOOL IN
PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE
AWARD OF THE DEGREE OF DOCTOR OF PHILOSOPHY IN
INDUSTRIAL DESIGN (GLASS TECHNOLOGY)
DEPARTMENT OF THE INDUSTRIAL DESIGN
FACULTY OF SCIENCE
AHMADU BELLO UNIVERSITY
ZARIA
NIGERIA.
DECEMBER, 2008
Keywords
DEVELOPMENT,, OF LOW TEMPERATURE,, GLASS,, CERAMIC,, LOCAL RAW MATERIALS