Design and sintering of Fe-Zro2 functionally graded materials
Dissertant
Thesis advisor
al-Zughaybi, Ala Abd al-Hasan Atiyyah Hasan
University
University of Technology
Faculty
-
Department
Department of Materials Engineering
University Country
Iraq
Degree
Master
Degree Date
2013
English Abstract
For many applications such as thermal protection systems, functionally graded materials are being developed to minimize thermal stresses which usually lead to fracture of ceramic materials.
The purpose of this research is to design, prepare and characterize the behavior of functionally graded materials through experimentation and analytical modeling.
This work involves two parts, the first part is design and the second is experimental work.
In this work a five layer metal to ceramic functionally graded materials have been prepared for high temperature applications such as jet engine using powder technology techniques.
The ceramic is represented by partially stabilized Zirconia (ZrO^) while metal is represented by iron (Fe).
The work starts with the design phase, where the FEM method has been used through the COMSOL package to find the best graded thickness (RF) that imparting low residual stresses between layers under variable volume fraction index (N).
Thermal stresses that are developed as a result of exposing of material for high temperature environments have been calculated.
Experimental part focuses on two stages; the first stage is the preparation of five layers FGMs according to the best results obtained ^om the modeling part.
Powder technology has been used extensively to prepare these materials.
Sintering practice examinations represent the second stage in practical parts.
Tuning of sintering temperature is accomplished and a model for sintering behavior is also investigated in this research.
The simulation shows that the sample (RF= 80%, N=0.
7) provides minimum residual stress (838 ^Pa) at high temperature 1000°c with good mechanical properties.
Landau theory of thermodynamics of sintering is adapted in this research.
Sintering conditions (1400°c ) for 5hr impart better graded microhardness along the thickness at modifying relative density (93.3%), lower porosity (6.7%).
Characterization of resulted sample by SEM is used to investigate the interactions between layers; these examinations could help in understanding the diffusion phenomena and its effects on the gradation of properties across the thickness of prepared materials.
Main Subjects
American Psychological Association (APA)
Aziz, Ahmad Taifor. (2013). Design and sintering of Fe-Zro2 functionally graded materials. (Master's theses Theses and Dissertations Master). University of Technology, Iraq
https://search.emarefa.net/detail/BIM-417283
Modern Language Association (MLA)
Aziz, Ahmad Taifor. Design and sintering of Fe-Zro2 functionally graded materials. (Master's theses Theses and Dissertations Master). University of Technology. (2013).
https://search.emarefa.net/detail/BIM-417283
American Medical Association (AMA)
Aziz, Ahmad Taifor. (2013). Design and sintering of Fe-Zro2 functionally graded materials. (Master's theses Theses and Dissertations Master). University of Technology, Iraq
https://search.emarefa.net/detail/BIM-417283
Language
English
Data Type
Arab Theses
Record ID
BIM-417283