Objetivo: validar o teste de tensão de polimerização através da correlação com resultados de diferentes testes de avaliação da qualidade de interface. Métodos: Foram testados sete compósitos comerciais: cinco compósitos à base de BisGMA (Filtek Z250/3M ESPE - FZ, Heliomolar/Ivoclar Vivadent - HM, Aelite LS Posterior/Bisco - AE, Filtek Supreme/3M ESPE - SU, ELS/Saremco - EL), um à base de uretano (Venus Diamond/Heraeus Kulzer - VD) e um à base de silorano (Filtek LS/3M ESPE - LS). A resistência de união foi analisada através do ensaio de push-out. Superfícies vestibulares de incisivos bovinos receberam preparos cavitários cônicos com =3,5mm na face vestibular e =2,9mm na face lingual (ambas superfícies livres) e h=2,0 mm. A razão entre a força máxima e a área aderida foi utilizada para o cálculo da resistência de união. Para o teste de microinfiltração e análise de fendas, incisivos bovinos receberam preparos cavitários cilíndricos na face vestibular, com margens em esmalte, com =4 mm e h=1,5 mm, os quais foram restaurados em bloco único. Foram obtidas réplicas em resina epóxica das restaurações, para análise de fendas em microscopia eletrônica de varredura (MEV, 200x). Após 24 horas de armazenamento em água a 37oC, os espécimes foram submetidos ao procedimento de microinfiltração pelo AgNO3. Após seccionados duas vezes, perpendicularmente, a microinfiltração foi determinada (em mm) em estereomicroscópio (60x). A deformação de cúspides (n=10) foi analisada em preparos MOD padronizados em pré-molares superiores humanos restaurados em bloco único utilizando-se extensometria. A tensão de polimerização (n=5) foi determinada pela inserção do compósito (h=1,5mm) entre dois bastões de poli(metacrilato de metila), PMMA, ou vidro (=4 mm). A razão entre a força de contração máxima registrada e a secção transversal do bastão foi utilizada para o cálculo da tensão nominal. Os dados foram analisados utilizando-se Kruskal-Wallis para microinfiltração e fendas e ANOVA/Tukey para resistência de união, deformação e tensão (=5%). O teste de Pearson foi utilizado para verificar correlações entre as variáveis. Resultados: Os dados de resistência de união variaram entre 4,7 e 7,9 MPa. Os dados de microinfiltração média variaram entre 0,34 e 0,89 mm. A microinfiltração máxima variou entre 0,61 e 1,34 mm. A incidência de fendas variou entre 13 e 47%. A deformação de cúspides variou entre 75,2 e 96,9 s para a cúspide palatina, e 58,5 e 66,8 s para a cúspide vestibular, sem diferença estatística entre os compósitos. A tensão de polimerização variou entre 2,5 e 4,4 MPa para o PMMA, e 2,1 e 8,2 para o vidro. Foram observadas correlações entre tensão e os testes de qualidade de interface apenas quando o compósito à base de silorano foi removido das análises. Essas correlações foram mais fortes quando o PMMA foi utilizado como substrato de colagem. Conclusões: Dentro das limitações deste estudo, pode-se concluir que a tensão desenvolvida em um sistema de teste utilizando PMMA como substrato de colagem é um preditor da qualidade de interface de restaurações realizadas in vitro utilizando de compósitos à base de dimatcrilatos. / Aim: to validate the polymerization stress test through correlations with the results from different interfacial quality tests. Methods: Seven comercial composites were tested. Five composites based on BisGMA (Filtek Z250/3M ESPE - FZ, Heliomolar/Ivoclar Vivadent - HM, Aelite LS Posterior/Bisco - AE, Filtek Supreme/3M ESPE - SU, ELS/Saremco - EL), one based on urethane (Venus Diamond/Heraeus Kulzer - VD) and one silorane based (Filtek LS/3M ESPE - LS). Bond strenght was evaluated by push-out test. Bovine incisors received conical cavities with =3,5mm on buccal surface and =2,9mm on lingual surface (both free surfaces) and h=2,0 mm. The ratio of maximum force and the adhered area was used for bond strength calculation. For the microleakage test and gap formation analysis, bovine incisors received cylindrical cavities with =4 mm and h=1,5 mm. Epoxy resin replicas were obtained of the buccal surface of restorations, to analysis gap formation using scanning electron microscopy (SEM, 200x). After 24 hours storage in water at 37oC, specimens were submitted to the microaleakage protocol by AgNO3. After sectioned twice perpendicularly, microleakage was determined using stereomicroscope (60x). The cusp deformation (n=10) was analysed in standardized MOD cavities in human upper premolars using strain gagea. Polymerization stress (n=5) was determined by the insertion of the composite (h=1,5mm) between rods of poly(methyl methacrylate), PMMA, or glass (=4 mm). The ratio of the maximum force of contraction recorded and the cross-sectional area of the rod were used the calculate the nominal stress. Data were analysed using Kruskal-Wallis for microleakage and gaps, and ANOVA/Tukey for bond strength, deformation and stress (=5%). Pearson test was used to verify correlations between variables. Results: Bond strenght data varied from 4,7 to 7,9 MPa. Average microleakage data varied from 0,34 to 0,89 mm. Maximum microleakage data varied from 0,61 to 1,34 mm. Gap data varied from 13 to 47%. Cusp deformation data varied from 75,2 to 96,9 s for lingual cusp, and 58,5 to 66,8 s for buccal cusp, without significant statical difference among composites. Polymerization stress data varied from 2,5 to 4,4 MPa for PMMA, and 2,1 to 8,2 for glass. Correlation were observes between stress and interfacial quality tests only when the LS composite was removed from the analysis. These correlations were stronger when PMMA was used as bonding substrate. Conclusions: Within the limitations of this study, the stress developed when the PMMA is used as bonding substrate is a predictor of interfacial quality tests analyzed, in restorations using dimethacrylates based composites.

Ka-fai Ho. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1999. / Includes bibliographical references. / Text in English; abstracts in English and Chinese. / Ka-fai Ho. / Acknowledgments --- p.i / Abstract --- p.ii / 摘要 --- p.iv / Figures Captions --- p.v / Tables Captions --- p.xii / Table of contents --- p.xiii / Chapter Chapter one --- Introduction --- p.1-1 / Chapter 1.1 --- Metal Matrix Composite --- p.1-1 / Chapter 1.1.1 --- Matrix Materials --- p.1-2 / Chapter 1.1.1.1 --- Aluminum --- p.1-2 / Chapter 1.1.1.2 --- Titanium --- p.1-3 / Chapter 1.1.2 --- Type of reinforcements --- p.1-3 / Chapter 1.2 --- Conventional Fabrication method --- p.1-4 / Chapter 1.2.1 --- Liquid Phase processing --- p.1-4 / Chapter 1.2.1.1 --- Slurry deposition --- p.1-4 / Chapter 1.2.1.2 --- Squeeze casing (Pressure infiltration) --- p.1-4 / Chapter 1.2.2 --- Solid Phase processing --- p.1-5 / Chapter 1.2.2.1 --- Diffusion bonding --- p.1-5 / Chapter 1.2.2.2 --- Powder Metallurgy (P/M) --- p.1-5 / Chapter 1.2.3 --- In-situ processing --- p.1-7 / Chapter 1.3 --- Sintering processing --- p.1-7 / Chapter 1.3.1 --- Pore structure --- p.1-8 / Chapter 1.3.2 --- Compression effect on sintering --- p.1-9 / References / Chapter Chapter Two --- Methodology and Instrumentation --- p.2-1 / Chapter 2.1 --- Al-Ti-C composites --- p.2-1 / Chapter 2.1.1 --- Introduction --- p.2-1 / Chapter 2.1.2 --- Aim and Motivation --- p.2-2 / Chapter 2.1.2.1 --- Compositions and Fabrications --- p.2-2 / Chapter 2.1.2.2 --- Testing --- p.2-3 / Chapter 2.1.3 --- The Flow of the Thesis --- p.2-3 / Chapter 2.2 --- Instrumentation --- p.2-4 / Chapter 2.2.1 --- Ball-milling machine --- p.2-4 / Chapter 2.2.2 --- High temperature furnace --- p.2-5 / Chapter 2.2.3 --- Arc-melting furnace --- p.2-5 / Chapter 2.2.4 --- Instron loading machine --- p.2-6 / Chapter 2.2.5 --- Density measurement --- p.2-6 / Chapter 2.2.6 --- Vickers' Hardness Tester --- p.2-8 / Chapter 2.2.7 --- X-ray diffraction analysis --- p.2-8 / Chapter 2.2.8 --- Scanning Electron Microscope (SEM) and Energy Dispersive X-ray Spectroscopy (EDXS) --- p.2-9 / References / Chapter Chapter Three --- Fabrication of Al-16Ti-C composites by Powder Metallurgy method --- p.3-1 / Chapter 3.1 --- Introduction --- p.3-1 / Chapter 3.2 --- Experiments --- p.3-1 / Chapter 3.2.1 --- Experiments on Pressing pressure --- p.3-1 / Chapter 3.2.2 --- Firing temperature and duration time --- p.3-2 / Chapter 3.3 --- Results --- p.3-2 / Chapter 3.3.1 --- Pressing pressure --- p.3-2 / Chapter 3.3.1.1 --- Relative Density --- p.3-2 / Chapter 3.3.1.2 --- Surface Porosity --- p.3-2 / Chapter 3.3.1.3 --- Microhardness --- p.3-3 / Chapter 3.3.1.4 --- X-ray diffraction analysis --- p.3-3 / Chapter 3.3.1.5 --- Microstructure --- p.3-3 / Chapter 3.3.2 --- Firing temperature and duration time --- p.3-4 / Chapter 3.3.2.1 --- Microhardness --- p.3-4 / Chapter 3.3.2.2 --- X-ray diffraction analysis --- p.3-4 / Chapter 3.3.2.3 --- Microstructure --- p.3-4 / Chapter 3.4 --- Discussion --- p.3-5 / Chapter 3.4.1 --- Pressing pressure --- p.3.5 / Chapter 3.4.2 --- Firing temperature and time duration --- p.3-6 / Chapter 3.5 --- Conclusions --- p.3-6 / References / Chapter Chapter Four --- Effects of the size of Aluminum powder on the properties of Al-16Ti-4C composites --- p.4-1 / Chapter 4.1 --- Introduction --- p.4-1 / Chapter 4.2 --- Experiments --- p.4-1 / Chapter 4.3 --- Results --- p.4-2 / Chapter 4.3.1 --- Relative density --- p.4-2 / Chapter 4.3.2 --- Microhardness --- p.4-3 / Chapter 4.3.3 --- Fracture Strength --- p.4-3 / Chapter 4.3.4 --- X-ray diffraction analysis --- p.4-3 / Chapter 4.3.5 --- Microstructure --- p.4-4 / Chapter 4.3.5.1 --- Microstructure of the surface --- p.4-4 / Chapter 4.3.5.2 --- Microstructure of the fracture surface --- p.4-4 / Chapter 4.4 --- Discussion --- p.4-5 / Chapter 4.4.1 --- Sintering procedure --- p.4-5 / Chapter 4.4.2 --- Fracture model --- p.4-6 / Chapter 4.4.3 --- X-ray diffraction analysis --- p.4-6 / Chapter 4.5 --- Conclusions --- p.4-7 / References / Chapter Chapter Five --- Effects of different sintering temperature on the properties of Al-16Ti-4C composites --- p.5-1 / Chapter 5.1 --- Introduction --- p.5-1 / Chapter 5.2 --- Experiments --- p.5-1 / Chapter 5.3 --- Results --- p.5-2 / Chapter 5.3.1 --- Relative density --- p.5-2 / Chapter 5.3.2 --- Microhardness --- p.5-2 / Chapter 5.3.3 --- Fracture Strength --- p.5-2 / Chapter 5.3.4 --- X-ray diffraction analysis --- p.5-2 / Chapter 5.3.5 --- Microstructure --- p.5-3 / Chapter 5.3.5.1 --- Surface microstructure --- p.5-3 / Chapter 5.3.5.2 --- Fracture surface microstructure --- p.5-3 / Chapter 5.4 --- Discussion --- p.5-3 / Chapter 5.4.1 --- Sintering procedure and microstructure --- p.5-3 / Chapter 5.4.2 --- Hardness and fracture strength --- p.5-4 / Chapter 5.4.3 --- Model of fracture --- p.5-5 / Chapter 5.5 --- Conclusions --- p.5-5 / Chapter Chapter Six --- Fabrication of TiC by Arc melting method --- p.6-1 / Chapter 6.1 --- Introduction --- p.6-1 / Chapter 6.2 --- Experiments --- p.6-2 / Chapter 6.3 --- Results --- p.6-2 / Chapter 6.3.1 --- X-ray diffraction analysis --- p.6-2 / Chapter 6.3.2 --- Microstructure --- p.6-2 / Chapter 6.4 --- Discussion --- p.6-2 / Chapter 6.4.1 --- Composition --- p.6-2 / Chapter 6.4.2 --- Sintering process --- p.6-3 / Chapter 6.5 --- Conclusions --- p.6-3 / References / Chapter Chapter Seven --- The Effects of the contents of Ti and C on the properties of Al-TiC and Al-Ti-C composites --- p.7-1 / Chapter 7.1 --- Introduction --- p.7-1 / Chapter 7.2 --- Experiments --- p.7-1 / Chapter 7.3 --- Results --- p.7-2 / Chapter 7.3.1 --- Relative density --- p.7-2 / Chapter 7.3.2 --- Microhardness --- p.7-2 / Chapter 7.3.3 --- Fracture Strength --- p.7-2 / Chapter 7.3.4 --- X-ray diffraction analysis --- p.7-3 / Chapter 7.3.5 --- Microstructure --- p.7-3 / Chapter 7.3.5.1 --- Surface microstructure --- p.7-3 / Chapter 7.3.5.2 --- Fracture surface microstructure --- p.7-4 / Chapter 7.4 --- Discussion --- p.7-4 / Chapter 7.4.1 --- Hardening effect --- p.7-4 / Chapter 7.4.2 --- Relationship between fracture strength and relative density --- p.7-4 / Chapter 7.4.3 --- Fracture model --- p.7-5 / Chapter 7.5 --- Conclusions --- p.7-5 / References / Chapter Chapter Eight --- Conclusions and Future Work --- p.8-1 / Chapter 8.1 --- Summary --- p.8-1 / Chapter 8.2 --- Future Work --- p.8-2 / References

by Che-Kit Lo. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references. / Text in English; abstracts in English and Chinese. / by Che-Kit Lo. / Acknowledgements --- p.i / Abstract --- p.ii / 摘要 --- p.iv / List of Tables --- p.v / List of Figures --- p.vi / Table of contents --- p.xi / Chapter Chapter 1 --- Metal matrix composites --- p.1-1 / Chapter 1.1 --- Introduction --- p.1-1 / Chapter 1.1.2 --- Conventional fabrication processes --- p.1-2 / Chapter 1.1.2.1 --- Solid phase processes --- p.1-2 / Chapter 1.1.2.1.1 --- Powder blending and consolidation --- p.1-2 / Chapter 1.1.2.1.2 --- Diffusion bonding --- p.1-3 / Chapter 1.1.2.2 --- Liquid phase processes --- p.1-3 / Chapter 1.1.2.2.1 --- Casting or liquid infiltration --- p.1-3 / Chapter 1.1.2.2.2 --- Squeeze infiltration --- p.1-3 / Chapter 1.1.2.2.3 --- Stir casting --- p.1-4 / Chapter 1.1.2.2.4 --- Spray deposition --- p.1-4 / Chapter 1.1.2.3 --- In-situ processes --- p.1-5 / Chapter 1.1.3 --- Applications of metal matrix composites --- p.1-5 / Chapter 1.1.3.1 --- Aerospace applications --- p.1-5 / Chapter 1.1.3.2 --- Non-aerospace applications --- p.1-6 / Chapter 1.1.3.3 --- Filamentary superconductors --- p.1-6 / Chapter 1.2 --- Reinforcements --- p.1-7 / Chapter 1.2.1 --- Particles reinforcements --- p.1-7 / Chapter 1.2.1.1 --- Definition of intemetallics --- p.1-7 / Chapter 1.2.1.2 --- Application of intemetallics --- p.1-8 / Chapter 1.2.2 --- Fiber reinforcements --- p.1-8 / Chapter 1.2.2.1 --- Definition of whisker --- p.1-8 / Chapter 1.2.2.2 --- Application of whisker --- p.1-9 / Chapter 1.3 --- Tungsten Aluminide --- p.1-9 / Chapter 1.3.1 --- Aluminum and its oxide --- p.1-10 / Chapter 1.3.2 --- Tungsten and its oxide --- p.1-11 / Chapter 1.4 --- Previous research work --- p.1-12 / Chapter 1.5 --- Recent research work --- p.1-13 / Chapter 1.6 --- Thesis layout --- p.1-14 / References / Chapter Chapter 2 --- Methodology and Instrumentation --- p.2-1 / Chapter 2.1 --- Introduction --- p.2-1 / Chapter 2.2 --- Powder metallurgy --- p.2-1 / Chapter 2.3 --- Fabrication methods --- p.2-3 / Chapter 2.3.1 --- Cold pressing --- p.2-3 / Chapter 2.3.2 --- Standard Sintering --- p.2-4 / Chapter 2.3.3 --- Argon tube furnace sintering --- p.2-5 / Chapter 2.3.4 --- Hot pressing --- p.2-5 / Chapter 2.4 --- Characterization methods --- p.2-6 / Chapter 2.4.1 --- Thermal analysis --- p.2-6 / Chapter 2.4.1.1 --- Differential Thermal Analyzer (DTA) --- p.2-6 / Chapter 2.4.2 --- Mechanical analysis --- p.2-7 / Chapter 2.4.2.1 --- Relative density measurement --- p.2-7 / Chapter 2.4.2.2 --- Tensile Tests --- p.2-8 / Chapter 2.4.2.3 --- Vickers Hardness Tests --- p.2-8 / Chapter 2.4.3 --- Structural analysis --- p.2-10 / Chapter 2.4.3.1 --- Scanning Electron Microscopy (SEM) --- p.2-10 / Chapter 2.4.3.2 --- X-Ray powder diffractometry (XRD) --- p.2-10 / References / Chapter Chapter 3 --- Thermal analysis on the reaction mechanism of the A1-W03 system --- p.3-1 / Chapter 3.1 --- Introduction --- p.3-1 / Chapter 3.2 --- Experimental details --- p.3-1 / Chapter 3.3 --- Results and discussions --- p.3-2 / Chapter 3.3.1 --- Analysis of the Al-58wt%W intermetallics --- p.3-2 / Chapter 3.3.2 --- Analysis of the Al-36wt%W intermetallics --- p.3-5 / Chapter 3.3.3 --- Analysis of the Al-30wt%WO3 intermetallics --- p.3-6 / Chapter 3.4 --- Conclusions --- p.3-8 / References / Chapter Chapter 4 --- Fabrication and characterization of A1-WO3 MMCs --- p.4-1 / Chapter 4.1 --- Introduction --- p.4-1 / Chapter 4.2 --- Experiments details --- p.4-1 / Chapter 4.3 --- Results and discussion --- p.4-2 / Chapter 4.3.1 --- X-Ray powder diffraction analysis --- p.4-2 / Chapter 4.3.2 --- Microstructure analysis (SEM) --- p.4-3 / Chapter 4.3.2.1 --- SEM micrographs of Hot pressed samples --- p.4-3 / Chapter 4.3.2.2 --- SEM micrographs of samples sintered in argon tube furnace --- p.4-4 / Chapter 4.4 --- Formation of A1-WO3 MMCs --- p.4-5 / Chapter 4.5 --- Conclusions --- p.4-5 / References / Chapter Chapter 5 --- Physical and mechanic properties of the A1-W03 MMCs / Chapter 5.1 --- Introduction --- p.5-1 / Chapter 5.2 --- Experiments details --- p.5-1 / Chapter 5.3 --- X-ray powder diffraction analysis --- p.5-1 / Chapter 5.4 --- Mechanic properties --- p.5-2 / Chapter 5.4.1 --- Relative density --- p.5-2 / Chapter 5.4.2 --- Vickers hardness measurement --- p.5-3 / Chapter 5.4.3 --- Tensile Strength measurement --- p.5-4 / Chapter 5.5 --- Conclusions --- p.5-5 / References / Chapter Chapter 6 --- Conclusions and future works --- p.6-1 / Chapter 6.1 --- Conclusions --- p.6-1 / Chapter 6.2 --- Future Works --- p.6-2

by Wai-Yuen Kwok = 氧化鋁及鋁-鉻金屬間化合物增強的鋁基複合材料的製造和表徵 / 郭瑋源. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references. / Text in English; abstracts in English and Chinese. / by Wai-Yuen Kwok = Yang hua lü ji lü--ge jin shu jian hua he wu zeng qiang de lü ji fu he cai liao de zhi zao he biao zheng / Guo Weiyuan. / Acknowledgements --- p.i / Abstract --- p.ii / 摘要 --- p.iv / List of tables --- p.vi / List of figures --- p.vii / Table of contents --- p.xiv / Chapter Chapter 1 --- Metal matrix composites --- p.1-1 / Chapter 1.1 --- Introduction --- p.1-1 / Chapter 1.1.2 --- Conventional fabrication processes --- p.1-2 / Chapter 1.1.2.1 --- Solid state processes --- p.1-2 / Chapter 1.1.2.1.1 --- Powder blending and consolidation --- p.1-2 / Chapter 1.1.2.1.2 --- Diffusion bonding --- p.1-3 / Chapter 1.1.2.2 --- Liquid state processes --- p.1-3 / Chapter 1.1.2.2.1 --- Casting or liquid infiltration --- p.1-3 / Chapter 1.1.2.2.2 --- Squeeze infiltration --- p.1-4 / Chapter 1.1.2.2.3 --- Stir casting --- p.1-4 / Chapter 1.1.2.2.4 --- Spray deposition --- p.1-5 / Chapter 1.1.2.3 --- In-situ processes --- p.1-5 / Chapter 1.1.3 --- Applications of metal matrix composites --- p.1-6 / Chapter 1.1.3.1 --- Aerospace applications --- p.1-6 / Chapter 1.1.3.2 --- Non-aerospace applications --- p.1-6 / Chapter 1.1.3.3 --- Filamentary superconductors --- p.1-7 / Chapter 1.2 --- Reinforcements in metal matrix composites --- p.1-7 / Chapter 1.2.1 --- Particles reinforcements --- p.1-8 / Chapter 1.2.1.1 --- Definition of intermetallics --- p.1-8 / Chapter 1.2.1.2 --- Applications of intermetallics --- p.1-9 / Chapter 1.2.2 --- Fiber reinforcements --- p.1-9 / Chapter 1.2.2.1 --- Definition of whisker --- p.1-9 / Chapter 1.2.2.2 --- Applications of whiskers --- p.1-10 / Chapter 1.3 --- Chromium Aluminide --- p.1-10 / Chapter 1.3.1 --- Aluminum and Aluminum (III) oxide --- p.1-11 / Chapter 1.3.2 --- Chromium and Chromium (III) oxide --- p.1-12 / Chapter 1.4 --- Previous work --- p.1-13 / Chapter 1.5 --- Current work --- p.1-14 / Chapter 1.6 --- Thesis layout --- p.1-15 / References / Chapter Chapter 2 --- Methodology and Instrumentation --- p.2-1 / Chapter 2.1 --- Introduction --- p.2-1 / Chapter 2.2 --- Powder metallurgy --- p.2-1 / Chapter 2.2.1 --- "Particle size, pressing pressure, sintering conditions" --- p.2-1 / Chapter 2.2.2 --- Sintering process --- p.2-2 / Chapter 2.3 --- Fabrication methods --- p.2-4 / Chapter 2.3.1 --- Sample preparation --- p.2-4 / Chapter 2.3.1.1 --- Al+Cr2〇3 composite samples --- p.2-4 / Chapter 2.3.2 --- Cold pressing --- p.2-4 / Chapter 2.3.3 --- Box furnace sintering (Sintering in air) --- p.2-5 / Chapter 2.3.4 --- Argon tube furnace sintering (Sintering in argon) --- p.2-5 / Chapter 2.3.5 --- Hot-press sintering --- p.2-6 / Chapter 2.3.6 --- Arc melting --- p.2-7 / Chapter 2.4 --- Characterization methods --- p.2-8 / Chapter 2.4.1 --- Thermal analysis - Differential thermal analyzer (DTA) --- p.2-8 / Chapter 2.4.2 --- Physical property analysis - Relative density measurement --- p.2-9 / Chapter 2.4.3 --- Mechanical property - Vickers hardness measurement --- p.2-10 / Chapter 2.4.4 --- Microstructural analysis - Scanning electron microscopy (SEM) --- p.2-10 / Chapter 2.4.5 --- Phases determination - X-ray powder diffractometry (XRD) --- p.2-11 / References / Chapter Chapter 3 --- Thermal analysis of Al-Cr203 powder mixture --- p.3-1 / Chapter 3.1 --- Introduction --- p.3-1 / Chapter 3.2 --- Experimental details --- p.3-2 / Chapter 3.3 --- Results --- p.3-2 / Chapter 3.3.1 --- DTA curves --- p.3-2 / Chapter 3.3.2 --- XRD patterns --- p.3-3 / Chapter 3.3.3 --- SEM micrographs --- p.3-4 / Chapter 3.4 --- Discussions --- p.3-5 / Chapter 3.5 --- Formation of Al-Cr203 MMCs --- p.3-8 / Chapter 3.6 --- Conclusions --- p.3-8 / References / Chapter Chapter 4 --- Fabrication and characterization of the Al-Cr203 MMCs --- p.4-1 / Chapter 4.1 --- Introduction --- p.4-1 / Chapter 4.2 --- Experimental details --- p.4-1 / Chapter 4.3 --- Results --- p.4-2 / Chapter 4.3.1 --- Al-MMCs produced by different sintering methods --- p.4-2 / Chapter 4.3.1.1 --- XRD patterns --- p.4-2 / Chapter 4.3.1.2 --- SEM micrographs --- p.4-4 / Chapter 4.3.2 --- Argon-sintered Al-MMCs with different sintering time --- p.4-6 / Chapter 4.3.2.1 --- XRD patterns --- p.4-6 / Chapter 4.3.2.2 --- SEM micrographs --- p.4-7 / Chapter 4.4 --- Discussions --- p.4-8 / Chapter 4.5 --- Mechanism in the formation of Al-Cr203 MMCs --- p.4-9 / Chapter 4.6 --- Conclusions --- p.4-10 / References / Chapter Chapter 5 --- Physical and mechanical properties of Al-Cr203 system --- p.5-1 / Chapter 5.1 --- Introduction --- p.5-1 / Chapter 5.2 --- Experimental details --- p.5-1 / Chapter 5.3 --- Relativity density --- p.5-2 / Chapter 5.3.1 --- Measurement --- p.5-2 / Chapter 5.3.2 --- Discussions --- p.5-4 / Chapter 5.4 --- Mechanical hardness --- p.5-5 / Chapter 5.4.1 --- Measurement --- p.5-5 / Chapter 5.4.2 --- Discussions --- p.5-6 / Chapter 5.5 --- Conclusions --- p.5-7 / References / Chapter Chapter 6 --- Fabrication and characterization of Al-Cr203 MMCs fabricated by arc melting --- p.6-1 / Chapter 6.1 --- Introduction --- p.6-1 / Chapter 6.2 --- Experimental Details --- p.6-1 / Chapter 6.3 --- Results --- p.6-2 / Chapter 6.3.1 --- Unannealed arc-melted samples --- p.6-2 / Chapter 6.3.1.1 --- XRD patterns --- p.6-2 / Chapter 6.3.1.2 --- SEM micrographs --- p.6-2 / Chapter 6.3.2 --- Annealed arc-melted samples --- p.6-4 / Chapter 6.3.2.1 --- XRD patterns --- p.6-4 / Chapter 6.3.2.2 --- SEM micrographs --- p.6-4 / Chapter 6.4 --- Discussions --- p.6-5 / Chapter 6.5 --- Formation of Al-MMCs during the arc-melting method --- p.6-6 / Chapter 6.6 --- Vickers hardness --- p.6-7 / Chapter 6.7 --- Conclusions --- p.6-8 / References / Chapter Chapter 7 --- Conclusions and future works --- p.7-1 / Chapter 7.1 --- Conclusions --- p.7-1 / Chapter 7.2 --- Future works --- p.7-2

In this work the potential of graphene-like particles for mechanical reinforcement is investigated. Different polymer processing methods are studied from traditional ones to more advanced techniques. The potential of graphene as a reinforcement for polymer composites is addressed as a result of polymer modifications and the morphology of the graphene like particles. First, a composites of polycarbonate (PC) and graphite nanoplatelets (GNP) are produced by a traditional melt-mixing method. The GNP composites present a low mechanical reinforcing efficiency which is believed to be due to a poor dispersion of the GNP and a weak interaction between the GNP and the matrix. Secondly, solution cast composites of polyvinyl alcohol (PVA) with very low loadings of graphene oxide (GO) are produced. The polymer morphology undergoes some modifications after the addition of GO. A strong increase of the Tg is observed after the addition of GO which is the result of a reduction in polymer mobility, while a dramatic increase of the mechanical properties is seen as well. Uni-axial drawing is applied in order to align the particles. No polymer modifications are observed between the drawn PVA and the drawn nanocomposites due to the strong alignment of the polymer chains during the drawing. Mechanical reinforcement is observed after addition of the GO showing real reinforcement. Finally, a more advanced processing method is investigated using spraying. The condition of spraying a layer of polymer and GO is studied. Finally a hierarchical composite of PVA - GO is produced by this spraying method. 150 bi-layers are deposited to create a film with improved mechanical properties at a loading of 5.4 wt.% GO. The Young’s modulus and strength of these films doubled or nearly doubled which is believed to be due to the high level of structural organization of the layered nanocomposite incorporating the 2D GO nanofiller, together with hydrogen bonding between the PVA and the GO sheets.

The aim of this study is to investigate a novel toughening approach for liquid mouldable carbon fibre/epoxy composites. The toughening mechanism is based on the use of thermoplastics for the toughening of epoxy resins in which polymer blends are formed, leading to phase separated morphologies which allows for various toughening mechanisms to take place. Instead of standard melt or solution blending, the thermoplastic in this study is introduced as solid phenoxy fibres, which are combined with dry carbon fabric preforms. These phenoxy fibres remain solid during resin infusion and dissolve when the laminates are heated and phase separation takes place before curing completed. The main benefits of this approach are that the viscosity of matrix resin remains low, which makes liquid moulding of these laminates possible. Localised and selective toughening of particular regions within a structure can also be achieved. Process time and cost can also be reduced by eliminating the polymer blending process. It was found that modification with phenoxy improved composite Mode-I interlaminar toughness significantly, with an increase of up to 10-folds for bifunctional epoxy composite and 100% for tetrafunctional epoxy composite, while tensile properties were not adversely affected. It was found that it is possible to combine the dissolvable phenoxy fibres with an undissolved aramid interleaf to improve toughness and damage properties. However, the phenoxy-epoxy systems had lowered environmental stability and degraded after hot-wet and solvent conditioning.

by Li, Tsui Kiu = 納米鋁酸鋰網絡增強的鋁基複合材料的製造和表徵 / 李翠翹. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references. / Text in English; abstracts in English and Chinese. / by Li, Tsui Kiu = Na mi lü suan li wang luo zeng qiang de lü ji fu he cai liao de zhi zao he biao zheng / Li Cuiqiao. / Acknowledgement --- p.i / Abstract --- p.ii / 摘要 --- p.iv / Table of contents --- p.vi / List of tables --- p.ix / List of figures --- p.xii / Chapter Chapter 1. --- Introduction / Chapter 1.1. --- Metal matrix composites (MMCs) --- p.1-2 / Chapter 1.1.1. --- Introduction --- p.1-2 / Chapter 1.1.2. --- Aluminum-based metal matrix composites (Al-MMCs) --- p.1-2 / Chapter 1.1.3. --- Applications of MMCs --- p.1-3 / Chapter 1.1.3.1. --- Automotive applications --- p.1-3 / Chapter 1.1.3.2. --- Aerospace applications --- p.1-4 / Chapter 1.1.4. --- Fabrication methods of metal matrix composites --- p.1-5 / Chapter 1.1.4.1. --- Stir casting --- p.1-5 / Chapter 1.1.4.2. --- Liquid metal infiltration --- p.1-5 / Chapter 1.1.4.3. --- Powder metallurgy --- p.1-6 / Chapter 1.1.4.4. --- The ex-situ sintering method --- p.6 / Chapter 1.1.4.5. --- The in-situ sintering method --- p.1-7 / Chapter 1.2. --- The Al-γ-LiA102 MMC --- p.1-7 / Chapter 1.2.1. --- Lithium aluminate (LiA102) --- p.1-8 / Chapter 1.2.2. --- Applications ofγ-LiA102 --- p.1-8 / Chapter 1.2.2.1. --- Ceramic matrices in molten carbonate fuel cell (MCFC) --- p.1-8 / Chapter 1.2.2.2. --- Tritium breeder materials in nuclear fusion reactors --- p.1-9 / Chapter 1.2.3. --- Fabrication methods ofγ-LiA102 --- p.1-10 / Chapter 1.2.3.1. --- Solid state reaction methods --- p.1-10 / Chapter 1.2.3.2. --- Sol-gel methods --- p.1-11 / Chapter 1.2.3.3. --- Hydrothermal treatment --- p.1-13 / Chapter 1.2.3.4. --- Ultrasonic Spray Pyrolysis --- p.1-13 / Chapter 1.2.3.5. --- The templated wet-chemical process --- p.1-13 / Chapter 1.2.3.6. --- Tape-casting --- p.1-14 / Chapter 1.2.3.7. --- Combustion Synthesis --- p.1-14 / Chapter 1.3. --- Previous works --- p.1-15 / Chapter 1.4. --- Current works --- p.1-16 / Chapter 1.5. --- Thesis layout --- p.1-17 / References / Chapter Chapter 2. --- Methodology and Instrumentation / Chapter 2.1. --- Introduction --- p.2-2 / Chapter 2.2. --- Powder Metallurgy --- p.2-2 / Chapter 2.3. --- Fabrication methods --- p.2-3 / Chapter 2.3.1. --- Tube furnace sintering --- p.2-3 / Chapter 2.3.2. --- Arc melting --- p.2-4 / Chapter 2.3.3. --- Annealing --- p.2-5 / Chapter 2.3.4. --- Sodium hydroxide etching --- p.2-5 / Chapter 2.4. --- Characterization methods --- p.2-6 / Chapter 2.4.1. --- Thermal analysis - Differential thermal analysis (DTA) --- p.2-6 / Chapter 2.4.2. --- Physical property analysis - Thermomechanical analyzer (TMA) --- p.2-6 / Chapter 2.4.3. --- Physical property analysis - The Archimedes' method --- p.2-7 / Chapter 2.4.4. --- Physical property analysis-Surface area and porosimetry analyzer --- p.2-8 / Chapter 2.4.5. --- Physical property analysis - Microhardness test --- p.2-9 / Chapter 2.4.6. --- Microstructural analysis - Scanning electron Microscopy (SEM) --- p.2-9 / Chapter 2.4.7. --- Surface morphology analysis - Atomic Force Microscopy (AFM) --- p.2-10 / Chapter 2.4.8. --- Phase determination - X-ray Diffractometry (XRD) --- p.2-11 / References / Chapter Chapter 3. --- Al-y-LiA102 MMC samples prepared by arc-melting / Chapter 3.1. --- Introduction --- p.3-2 / Chapter 3.2. --- Experimental details --- p.3-3 / Chapter 3.3. --- XRD analysis --- p.3-4 / Chapter 3.4. --- Microstructures --- p.3-5 / Chapter 3.5. --- NaOH etching time effects --- p.3-5 / Chapter 3.6. --- The 2-minute-etched sample --- p.3-6 / Chapter 3.7. --- Physical properties analysis --- p.3-7 / Chapter 3.7.1. --- Apparent density --- p.3-7 / Chapter 3.7.2. --- Microhardness --- p.3-7 / Chapter 3.7.3. --- BET analysis --- p.3-8 / Chapter 3.8. --- Formation mechanism ofγ-LiA102 network --- p.3-9 / Chapter 3.9. --- Effects ofLi20 contents --- p.3-10 / Chapter 3.9.1. --- Effects of Li2O contents on structure and compositions of MMCs --- p.3-10 / Chapter 3.9.2. --- Effects of Li2O- contents on coefficient of thermal expansion (CTE) --- p.3-11 / Chapter 3.10. --- Conclusions --- p.3-12 / References / Chapter Chapter 4. --- Al-y-LiAlO2 MMCs samples prepared by furnace sintering / Chapter 4.1. --- Introduction --- p.4-2 / Chapter 4.2. --- Experimental details --- p.4-2 / Chapter 4.3. --- The effects of sintering temperature --- p.4-3 / Chapter 4.3.1. --- Microstructures --- p.4-3 / Chapter 4.3.2. --- XRD analysis --- p.4-4 / Chapter 4.4. --- Prolonged NaOH etching --- p.4-5 / Chapter 4.5. --- Effects of annealing temperature --- p.4-7 / Chapter 4.6. --- DTA analysis of over-etched sample --- p.4-7 / Chapter 4.7. --- Thermal stability of the as-synthesized γ-LiA1O2 powders --- p.4-8 / Chapter 4.8. --- Conclusions --- p.4-9 / References / Chapter Chapter 5. --- Y-LiA1O2 pellets / Chapter 5.1. --- Introduction --- p.5-2 / Chapter 5.2. --- Experimental details --- p.5-2 / Chapter 5.3. --- Pellets fabricated by method 1 --- p.5-3 / Chapter 5.4. --- CTE and volume fraction of MMCs --- p.5-4 / Chapter 5.5. --- Pellets fabricated by method II --- p.5-5 / Chapter 5.6. --- Comparisons of γ-LiA1O2 fabricated by method I and method II --- p.5-6 / Chapter 5.7. --- Conclusions --- p.5-7 / References / Chapter Chapter 6. --- Conclusions and future works / Chapter 6.1. --- Conclusions --- p.6-2 / Chapter 6.2. --- Suggestions for future work --- p.6-3 / Chapter 6.2.1. --- Stability test of y-LiA1O2 in molten carbonates --- p.6-3 / Chapter 6.2.2. --- Investigation of the pore size distribution of γ-LiAIO2 network --- p.6-4 / Chapter 6.2.3. --- Fabrication of Al-γ-LiA1O2 MMC by hot isotatic pressing --- p.6-4 / Chapter 6.2.4. --- Mechanical tests --- p.6-4 / Chapter 6.2.5. --- Development of gas sensors --- p.6-5 / References

by Hon Wan Man = 鎂和硼化鎂複合材料的研究 / 韓韻文. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references. / Text in English; abstracts in English and Chinese. / by Hon Wan Man = Mei he peng hua mei fu he cai liao de yan jiu / Han Yunwen. / Abstract --- p.i / 摘要 --- p.iii / Acknowledgements --- p.v / Table of contents --- p.vi / List of tables --- p.x / List of figures --- p.xi / Chapter Chapter 1 --- Introduction --- p.1-1 / Chapter 1.1. --- Background --- p.1-1 / Chapter 1.1.1. --- Conventional and unconventional superconducting materials --- p.1-1 / Chapter 1.1.2. --- Type I and type II superconductors --- p.1-2 / Chapter 1.1.3. --- Critical Temperature and Magnetic Properties (M-H Loops) --- p.1-4 / Chapter 1.2. --- Magnesium Diboride MgB2 --- p.1-6 / Chapter 1.2.1. --- Introduction --- p.1-6 / Chapter 1.2.2. --- Potential application and recent work of MgB2 --- p.1-6 / Chapter 1.2.2.1. --- Thin films --- p.1-7 / Chapter 1.2.2.2. --- Wires and tapes --- p.1-8 / Chapter 1.2.2.3. --- Powders and single crystal --- p.1-8 / Chapter 1.2.3. --- Factors affecting critical temperature in MgB2 --- p.1-9 / Chapter 1.2.3.1. --- Critical temperature versus lattice constants --- p.1-9 / Chapter 1.2.3.2. --- Critical temperature versus pressure --- p.1-9 / Chapter 1.3. --- Mg-based metal matrix composites (Mg-MMCs) --- p.1-10 / Chapter 1.4. --- Objectives and approaches --- p.1-11 / Chapter 1.5. --- Thesis layout --- p.1-12 / Chapter 1.6. --- References --- p.1-13 / Figures --- p.1-16 / Tables --- p.1-20 / Chapter Chapter 2 --- Methodology and instrumentation --- p.2-1 / Chapter 2.1. --- Introduction --- p.2-1 / Chapter 2.2. --- Experimental procedures --- p.2-1 / Chapter 2.3. --- Samples fabrication --- p.2-2 / Chapter 2.3.1. --- Powder metallurgy method (P/M) --- p.2-2 / Chapter 2.3.2. --- Argon atmosphere tube furnace heat treatment --- p.2-3 / Chapter 2.4. --- Characterization --- p.2-3 / Chapter 2.4.1. --- Differential thermal analyzer (DTA) --- p.2-3 / Chapter 2.4.2. --- X-ray powder diffractometry (XRD) --- p.2-4 / Chapter 2.4.3. --- Hot mounting and polishing --- p.2-4 / Chapter 2.4.4. --- Scanning electron microscopy (SEM) --- p.2-5 / Chapter 2.4.5. --- Transmission electron microscopy (TEM) --- p.2-5 / Chapter 2.4.6. --- Vibrating sample magnetometer (VSM) --- p.2-6 / Chapter 2.5. --- References --- p.2-8 / Figures --- p.2-9 / Chapter Chapter 3 --- Effects of sintering temperature on Mg-MgB2 composites --- p.3-1 / Chapter 3.1. --- Introduction --- p.3-1 / Chapter 3.2. --- Experimental results --- p.3-1 / Chapter 3.2.1. --- DTA and XRD analyses --- p.3-1 / Chapter 3.2.2. --- Microstructures --- p.3-2 / Chapter 3.2.2.1. --- Green sample --- p.3-2 / Chapter 3.2.2.2. --- Sample sintered at 550°C --- p.3-3 / Chapter 3.2.2.3. --- Sample sintered at 600°C --- p.3-4 / Chapter 3.2.2.4. --- Sample sintered at 700°C --- p.3-4 / Chapter 3.2.2.5. --- Hexagonal platelets --- p.3-5 / Chapter 3.2.3. --- Superconducting behaviors --- p.3-5 / Chapter 3.2.3.1. --- Critical temperature (Tc) comparison --- p.3-5 / Chapter 3.2.3.2. --- Magnetization loops (M-H loops) --- p.3-6 / Chapter 3.3. --- Discussions --- p.3-7 / Chapter 3.4. --- Conclusions --- p.3-9 / Chapter 3.5. --- References --- p.3-10 / Figures --- p.3-11 / Tables --- p.3-20 / Chapter Chapter 4 --- Effects of composition on Mg-MgB2 composites --- p.4-1 / Chapter 4.1. --- Introduction --- p.4-1 / Chapter 4.2. --- Experimental results --- p.4-1 / Chapter 4.2.1. --- XRD results --- p.4-1 / Chapter 4.2.2. --- Microstructures --- p.4-2 / Chapter 4.2.2.1 --- Mg-0 wt % B (Pure Mg) sintered at 650。C --- p.4-2 / Chapter 4.2.2.2 --- Mg-47 wt % B sintered at 650°C --- p.4-2 / Chapter 4.2.2.3 --- Amount of B in Mg sample --- p.4-3 / Chapter 4.2.2.3.1. --- Overview of Mg-5 to 40 wt % B --- p.4-3 / Chapter 4.2.2.3.2. --- MgB2 phase in different composition (Mg-5 to 47 wt %B) --- p.4-4 / Chapter 4.2.2.3.3. --- MgO phase in different composition (Mg-0 to 30 wt % B) --- p.4-4 / Chapter 4.2.3. --- VSM results (Critical temperature Tc comparison) --- p.4-5 / Chapter 4.3. --- Discussions --- p.4-6 / Chapter 4.4. --- Conclusions --- p.4-8 / Chapter 4.5. --- References --- p.4-10 / Figures --- p.4-11 / Table --- p.4-18 / Chapter Chapter 5 --- Growth Mechanisms --- p.5-1 / Chapter 5.1. --- Introduction --- p.5-1 / Chapter 5.2. --- Brief summary of SEM result --- p.5-1 / Chapter 5.3. --- Growth Mechanism of MgB2 --- p.5-2 / Chapter 5.4. --- Comparison of MgB2 grain size by XRD result --- p.5-7 / Chapter 5.5. --- Stoichiometric Ratio of MgB2 in different temperature --- p.5-7 / Chapter 5.6. --- Growth of the MgB2 platelets --- p.5-8 / Chapter 5.7. --- Conclusions --- p.5-10 / Chapter 5.8. --- References --- p.5-11 / Figures --- p.5-12 / Table --- p.5-15 / Chapter Chapter 6 --- Conclusions and Future Works --- p.6-1 / Chapter 6.1. --- Conclusions --- p.6-1 / Chapter 6.2. --- Future works --- p.6-2 / Chapter 6.3. --- References --- p.6-4

Due to their unique structure and flexible choice of materials, electrospun degradable and biocompatible polymer fibres are considered to be extremely suitable for biomedical applications such as tissue engineering and drug delivery, either on their own or integrated within composites. Conventional electrospun fibre composites are typically based on non-woven mats and therefore limited to simple-curved geometries (films, membranes, etc.). For aqueous composites such as hydrogels, the hydrophobicity of the materials sometimes prohibits fibres to be easily integrated or distributed in these composites. In this thesis, a review on the topic is firstly presented in Chapter 2, introducing and discussing engineering of electrospun fibre as well as their biomedical applications. In Chapter 3, electrospun polylactide (PLA) fibres reinforced poly(trimethylene carbonate) (PTMC) composites are prepared. The composites are loaded with both continuous and short PLA fibres, achieving significant mechanical enhancement and offering opportunities to produce composites conveniently using liquid formulations. Chapter 4 presents the development of shape memory polymer composites based on a combination of PLA fibres and a PTMC matrix. By loading different amounts of short fibres with different aspect ratios or by using plasticisers, the shape memory behaviour is modulated; and composites of more complex geometries are produced. In Chapter 5, PTMC-PLA fibre composites are made into drug release system. Dexamethasone-loaded PLA fibres are integrated into a PTMC matrix, showing sustained drug release and stimulating stem cell osteogenic differentiation. This concept gives promise to loading various drugs into photo-crosslinked structures without denaturation. In Chapter 6, electrospun PLA fibres are functionalized by amphiphilic block copolymer polylactide-block-poly[2-(dimethylamino)ethyl methacrylate] (PLA-b-PDMAEMA) for the development of carboxymethylcellulose composites hydrogels. Functionalization of PLA fibres not only allows for easy integration and dispersion into the hydrogel, but also enhances the interfacial bonding between fibre and hydrogel. In the last chapter (Chapter 7), some conclusions are drawn and future works are discussed.

Cette thèse vise à étudier le comportement multiéchelle (nano-, micro- et macroscopique) des composites, basé sur une étude fine utilisant les techniques les plus modernes pour comprendre les interfaces et les quantifier. Deux séries de renforts sur une échelle micrométrique, des fibres de carbone (CF) et des matériaux à base de graphène ont été utilisées ici. Pour améliorer l'interaction entre les nanorenforts et la matrice polymère, deux voies principales ont été utilisées dans cette thèse : l'oxydation des renforts et la greffe de nanotubes de carbone sur leur surface.L'étude en elle-même a été menée à une échelle microscopique pour étudier la résistance interfaciale entre une fibre de carbone (CF) et la matrice époxy, avec des essais de traction effectués in situ dans la chambre d'un microscope à double colonne MEB-FIB (microscope électronique à balayage couplé à un faisceau d'ions focalisé). Le faisceau d'ions a été utilisé pour découper une éprouvette de traction du composite contenant à la fois de l'époxy et de la CF. Le champ de tractiona été appliqué via le nanomanipulateur et l'essai a été observé via les deux colonnes ionique et électronique (sous deux angles de vue différents) et a permis d'estimer le champ de déformation, et donc la résistance interfaciale au moment de la rupture. Une expérience similaire a été menée sur un composite où les renforts sont des nanoplaquettes de graphène.Enfin, l'étude en microscopie électronique en transmission de la région de l'interface entre l'époxy et les renforts a révélé la présence d'une interphase et a permis de mesurer son épaisseur et donner une indication de sa nature. À cette fin, une analyse EELS (spectroscopie par pertes d'énergie des électrons) a été effectuée, permettant de mesurer la densité de l'échantillon très localement (taille de sonde de l'ordre du dixième de nanomètre) en travers ou parallèlement à l'interface. Un scénario sur les modes de liaison chimique entre les deux milieux en fonction du traitement de surface utilisé permet d'expliquer la nature des interphases observées. / This thesis aims to investigate the multiscale (nano-, micro-, and macro-scopic) behavior of the composites based on a fine investigation using the most modern techniques, to understand the interfaces and to quantify them. Two series of reinforcements on a micrometer scale, carbon fibers (CFs) and graphene-based materials, were studied here. To improve the interactions between these nanofillers and the surrounding polymer matrix, two major routes were used in this thesis: the oxidation of the fillers and the grafting of carbon nanotubes on their surface.The study itself was conducted on a microscopic scale on the interfacial strength between CFs and the epoxy matrix, with tensile tests carried out in-situ in the chamber of a double-column FIB-SEM microscope (scanning electron microscope coupled to a focused ion beam). The ion beam was used to mill a thin bond-shaped tensile specimen of composite containing both an epoxy and a CF part. Thetensile stress field was applied using the nanomanipulator and the test was observed both via the ionic and the electronic columns (with two different angles of view) to estimate the strain field, hence the interfacial strength when the failure is observed. A similar experiment was led on a composite with GNPs.Finally, the transmission electron microscopy (TEM) study of the interface region between the epoxy and the graphene-based nanofillers revealed the existence of an interphase and allowed to measure its thickness and give an indication of its nature. For this purpose, an EELS (electron energy-loss spectroscopy) analysis was carried out, making it possible to measure the density of the sample very locally (probe size of the order of a tenth of a nanometer) across or parallelly to an interface. A scenario on the chemical bonding modes between the two media as a function of the surface treatment used makes it possible to explain the nature of the observed interphases.