dc.contributor.author | Nyongesa, Francis W | |
dc.date.accessioned | 2013-05-08T09:38:30Z | |
dc.date.available | 2013-05-08T09:38:30Z | |
dc.date.issued | 1994 | |
dc.identifier.citation | Master of Science | en |
dc.identifier.uri | http://erepository.uonbi.ac.ke:8080/xmlui/handle/123456789/20232 | |
dc.description.abstract | Characterization of cerami.c materials is important in order to improve
their quality. In this study uLtrason io nondestructive technique has
been used to characterize some Kenyan clay refractories. Ultrasonic:
parameters used for characterization were velocity and frequency
dependent attenuation measurements. It was found that the ultrasonic
parameters are influenced by the material fabrication conditions.
The measured ultrasonic velocity in the clay refractories was found to
mcrease as the firing temperature and/or the compaction (loading)
pressure were increased. Meanwhile the ultrasonic attenuation
decreased with increase in the firing temperature and/or the
compaction pressure. Further, clay refractories fabricated from
different types of clay, (red firing' clay -RFC and red hill clay -RHC)
gave different velocity and attenuation values. Ultrasonic velocity in
refractories fabricated from the clays with a 'finer' particle Slze
distribution (WC) was higher' than that in refractories fabricated
from clays with a coarser particle size distribution (RHC).
The nateri.e.Iproperties such as
linear drying shrinkage -%LDSf and
were also found to increase with
bulk density and shrinkage (both
linear firing shr-inkage -%LFSd)
increasing firing temperature or
loading pressure. Further, high shrinkage values were noted in samples
with a 'finer' particle size distribution (RFC).
X-ray diffraction (XRD) and chemical (rational) analysis showed that
the proportions of most of the major clay minerals (such as quartz,
mica and feldspar) increased as firing temperature was increased. The
proportion of kaolinite however dropped with temperature. | en |
dc.description.sponsorship | University of Nairobi | en |
dc.language.iso | en | en |
dc.title | Ultrasonic characterization of Kenyan clay Refractories | en |
dc.type | Thesis | en |
local.publisher | Department of Physics - University of Nairobi. | en |