Influence of B2O3 additions on the microstructure of mica based glass-ceramics

Download
index.pdf
2005
Aykut, Hakan
Show full item record
193
views
106
downloads
Mica based glass - ceramics have been produced by subjecting the glasses in the SiO2 , Al2O3 , CaO , MgO, K2O , and F system to a controlled heat treatment called crystallization. TiO2 was added into the batch in the amount of 1 wt% of the glass as nucleating agent. B2O3 additions in the amounts of 1, 2, 4 and 8 wt% of the glass have been made in the batch to see and evaluate the effects of B2O3 additions on the texture of the mica glass ceramics. Crystallization was accomplished in two steps, nucleation and crystal growth. Nucleation temperature was 650 ?C. Crystal growth temperatures were 850 and 1000 ?C. The time for holding the specimens at the temperatures was 8 hours. The X-Ray diffraction analysis revealed that resultant glass ceramics possessed not only synthetic fluormica crystals called phlogopite which provide machinability, but also wollastonite crystals which provide biocompatibility. The scanning electron microscopy examinations have indicated that the amount and distribution of the crystalline phases varied as a function of B2O3 content and heat treatment schedule applied.
Metallurgy.
http://etd.lib.metu.edu.tr/upload/12606060/index.pdf
https://hdl.handle.net/11511/15062
Graduate School of Natural and Applied Sciences, Thesis

Suggestions

Investigation of the effect of orientation and heat treatment on the stress corrosion cracking susceptibility of 7050 aluminium alloy
Çevik, Gül; Doruk, Mustafa; Department of Metallurgical and Materials Engineering (2004)
In the present work, the effect of variation in specimen orientation and heat treatment on the Stress Corrosion Cracking (SCC) susceptibility of 7050 aluminum alloy was investigated in 3,5% NaCl solution and under freely corroding conditions. For this purpose, Constant Extension Rate Tests (CERT) was performed on precracked Compact Tension (CT) specimens and the Direct Current Potential Drop technique was applied to measure the crack lengths. In addition to crack length versus time curves, the relationship ...
Characterization of magnetite thin films produced by sol-gel processing
Eken, Ali Erdem; Özenbaş, Ahmet Macit; Department of Metallurgical and Materials Engineering (2008)
Magnetite (Fe3O4) thin films were prepared by a sol-gel process in which, a solution of iron (III) nitrate dissolved in ethylene glycol was applied on glass substrates by spin coating. Xerogel films were obtained by drying the coated films at 110 °C. The films were sintered between 300 °C and 450 °C in order to observe the phases existing in the films at different temperatures. Coating solution showed Newtonian behaviour and viscosity was found as 0.0215 Pa.s. DTA analysis showed that, sintering temperature...
An investigation of the microstructural and mechanical properties of tri-calcium phosphates doped with aluminum and fluoride ions
Tahmasebifar, Aydin; Evis, Zafer; Department of Engineering Sciences (2011)
The aim of this study was to investigate the microstructure and mechanical properties of pure tricalcium phosphate (TCP) and tricalcium phosphates doped with aluminum (Al3+) and fluoride (F-) ions at different compositions. TCP was synthesized via precipitation method and sintered at 1100C for 1 and 5 h. It was observed that density and relative density of the sintered materials were decreased by extending the sintering time. Increased densities were achieved upon Al3+ and/or F- doping. For structural anal...
Effect of TiH2 particle size on foaming of aluminium
Kubilay, Ceylan; Öztürk, Tayfur; Department of Metallurgical and Materials Engineering (2005)
A study is carried out on the production of aluminum foams via powder processing. The study deals mainly with the effect of TiH2 particle size on the process of foaming. Mainly two TiH2 particle sizes were used; namely 27,5 ?m and 8,5 ?m. Foaming experiments were carried out at temperatures between 675oC ا 840oC. The viscosity of the system is adjusted by controlled addition of Al2O3. The study shows that choice of foaming agent size is influential in the foaming process. With the use of fine foaming agent,...
Characterization of maghemite thin films prepared by sol-gel processing
Karakuşçu, Aylin; Özenbaş, Ahmet Macit; Department of Metallurgical and Materials Engineering (2006)
In this study, maghemite (γ-Fe2O3) thin films were prepared by chemical solution deposition on glass and quartz substrates. The solution was prepared by using 0.3 M iron (III) nitrate [Fe(NO3)3 - 9H2O] as precursor and dissolved in a mixture of 2-methoxyethanol and acetylacetone in a molar ratio of 20:2, by stirring the solution at RT for 2 hours. Substrates were prepared by either piranha etching method or ultrasonic cleaning method. The solution was spin coated on glass and quartz substrates at 1400 and 4...
Citation Formats
H. Aykut, “Influence of B2O3 additions on the microstructure of mica based glass-ceramics,” M.S. - Master of Science, Middle East Technical University, 2005.
METU IIS - Integrated Information Service open@metu.edu.tr