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Visar resultat 1 - 5 av 155 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Atom Probe Tomography of Hard Nitride and Boride Thin Films

   Författare :David L. J. Engberg; Lars Hultman; Magnus Odén; Guido Schmitz; Linköpings universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Materials science; Atom probe tomography APT ; Ceramics; Nitrides; Borides;

   Sammanfattning : Hard ceramic thin films, including TiSiN, ZrAlN, ZrB2, and ZrTaB2, with applications for wear-resistant coatings, have been studied using atom probe tomography and correlated with several other analytical techniques, including X-ray diffraction, electron microscopy, and elastic recoil detection analysis. Outstanding obstacles for quantitative atom probe tomography of ceramic thin films have been surmounted. LÄS MER

3. 2. Rapid sintering of ceramics by intense thermal radiation

   Författare :Duan Li; Zhijian Shen; Lutz-Michael Berger; Stockholms universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Sintering; sintering by intense thermal radiation; spark plasma sintering; heat transfer; mass transfer; scattering; coalescence; densification; grain growth; numerical simulation; porous ceramic; foaming; nanostructure; hierarchical heterogeneities; permeability; Materials Chemistry; materialkemi;

   Sammanfattning : Sintering is an important processing step for obtaining the necessary mechanical stability and rigidity of ceramic bulk materials. Both mass and heat transfer are essential in the sintering process. The importance of radiation heat transfer is significantly enhanced at high temperatures according to the well-known Stefan-Boltzmann’s law. LÄS MER

4. 3. Spark plasma sintered ZrO2-SiO2 glass ceramics and Si3N4 bioceramics

   Författare :Le Fu; Wei Xia; Håkan Engqvist; Jérôme Chevalier; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; ZrO2-SiO2 glass ceramic; high-strength; translucency; 3D nano-architecture; Si3N4 bioceramic; biodegradable; spark plasma sintering; Materialvetenskap; Materials Science;

   Sammanfattning : This thesis focuses on elaboration and characterization of two types of bioceramics: one is ZrO2-SiO2 nanocrystalline glass ceramic (NCGC) for dental application. The goal is to develop new ZrO2-SiO2 NCGCs with a combination of high strength and high translucency; the other is biodegradable Si3N4 ceramics for spinal fusion. LÄS MER

5. 4. Advanced Functional Materials for Intermediate-Temperature Ceramic Fuel Cells

   Författare :Zhan Gao; Bill Bergman; Mogens Mogensen; Ceramics; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Sammanfattning : Low to intermediate-temperature solid oxide fuel cell (SOFC, 500 oC-700 oC) based on doped ceria (DCO) electrolyte has attracted much attention during the last decade. However, DCO suffers from electronic conduction caused byreduction of Ce (IV) to Ce (III) at high temperatures and low oxygen partial pressures and has a high grain-boundary resistivity. LÄS MER

7. 5. Advanced BaZrO3-BaCeO3 Based Proton Conductors Used for Intermediate Temperature Solid Oxide Fuel Cells (ITSOFCs)

   Författare :Junfu Bu; Pär Jönsson; Zhe Zhao; Mogens Mogensen; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Solid oxide fuel cells SOFCs ; Intermediate temperature solid oxide fuel cells ITSOFCs ; Electrolyte; Electrochemical impedance spectroscopy EIS ; Barium zirconate BaZrO3 ; Barium cerate BaCeO3 ; Solid-state reaction SSR ; Sintering; Conventional sintering CS ; Solid-state reactive sintering SSRS ; Spark plasma sintering SPS ; Ionic conductivity; Oxygen ion conductivity; Proton conductivity; Electronic conductivity; Oxygen ion conductor; Proton conductor; Oxygen partial pressure OPP ; Composite electrolyte; Materials Science and Engineering; Teknisk materialvetenskap;

   Sammanfattning : In this thesis, the focus is on studying BaZrO3-BaCeO3 based proton conductors due to that they represent very promising proton conductors to be used for Intermediate Temperature Solid Oxide Fuel Cells (ITSOFCs). Here, dense BaZr0.5Ce0.3Y0. LÄS MER