Authors: Ivo Dlouhý, Zdeněk Chlup, Aldo Roberto Boccaccini
Abstract: A number of examples exist that indicate the potential for increasing the toughness of brittle matrices by dispersing different reinforcements. For further development of these advanced materials the actual material response during mechanical loading under presence of flaws appears to be important. Theoretical and experimental knowledge acquired on different kinds of brittle matrix composites is summarised in the paper. These include glass matrix composites with metallic particles, alumina platelets, continuous SiC (Nicalon®) fibres, and both chopped fibres and ZrO2particles (hybrid composites). The composites were tested in as-received state but also after different forms of thermomechanical loading, e.g. thermal shock, thermal cycling in air, which were investigated according to the envisaged composites application. Chevron notch technique was mainly used for fracture toughness evaluation. Microstructural damage is explained based on identified fracture micromechanisms.
115
Authors: Hyo Jin Kim, Do Won Seo, Jae Kyoo Lim, Toru Fujii
417
Authors: Yan Yan Lu, Hua Li, Bo Kai Ng, Chen Xin Chen, Hong Mei Kang, Li Jiang, He Zhou Liu
Abstract: In this paper, electron beam radiation technology was applied to the preparation of MMT/MWNTs/epoxy nano-composites. The influences of the addition of Montmorillonite (MMT) and multi-walled carbon nanotubes (MWNTs) on the tensile properties of MMT/MWNTs/epoxy nano-composites were examined. The fracture surface of the composites was characterized by SEM as well. The results indicated that the composites have higher tensile modulus than that of the pristine epoxy resin.
458
Authors: Ying Cao, Li Pan
Abstract: In the present investigation, resin transfer molding has been used to produce high quality carbon fiber epoxy composites and nanotube-reinforced carbon fiber epoxy composites. To study the influence of carbon nanotubes (CNTs) on improving the mechanical properties and fatigue life, the tension-tension fatigue test has been carried out on those two kinds of material in the fiber direction. The damage mechanism in the fiber directions was analyzed by X-ray radiography and electron microscopy. The results show that CNTs pulled out, rapture and bridged cracks during the test, the results also show that CNTs possess an obvious potential on improving the property of carbon fiber epoxy composite, especially for properties that dominated by matrix.
753
Authors: A. Quddos, Mohammad Bilal Khan, R.N. Khan, M.K.K. Ghauri
Abstract: The impregnation of the fiber with a resin system, the polymeric matrix with the interface needs to be properly cured so that the dimensional stability of the matrix and the composite is ensured. A modified epoxy resin matrix was obtained with a reactive toughening agent and anhydride as a curing agent. The mechanical properties of the modified epoxy matrix and its fiber reinforced composites were investigated systematically.
The polymeric matrix possessed many good properties, including high strength, high elongation at break, low viscosity, long pot life at room temperature, and good water resistance. The special attentions are given to the matrix due to its low out gassing, low water absorption and radiation resistance. In addition, the fiber-reinforced composites showed a high strength conversion ratio of the fiber and good fatigue resistance. The dynamic and static of the composite material were studied by thermo gravimetric analysis (TGA), Differential Scanning Calorimetry (DSC) and Scanning Electron Microscopy (SEM) with EDX. The influences of processing technique such as curing and proper mixing on the mechanical and interfacial properties were determined.
The results demonstrated that the modified epoxy resin matrix is very suitable for applications in products fabricated with fiber-reinforced composites.
577