High Activated Mineral Admixture Slurry Made by Wet-discharged Fly-ash Promoted by Matrix Bonding Component

The mineral admixture slurry was made by wet-discharged fly-ash （WDFA） promoted by matrix bonding component （MBC）, and the strengths, hydration products change （XRD, SEM） of cement paste made by the slurry were studied. The results indicate that in the process of wet-milling preparation, there is a prime proportion （70︰30） between wet-discharged fly-ash and matrix bonding component in the slurry. The physical activation of wet-milling and chemical activation of modified agents accelerate the hydration of cement including the cement and mineral which has not hydrated completely in the matrix bonding component. And the hydrated part of matrix bonding component can play the function of inducing crystallization, which can accelerate secondary hydration reaction of fly-ash.

Improvement of the matrix and the interface quality of a Cu/Al composite by the MARB process

The matrix accumulative roll bonding technology （MARB） can improve the matrix performance of metal composite and strengthen the bonding quality of the interface./n this research, for the fwst time, the technology of MARB was proposed. A sound Cu/AI bonding composite was obtained using the MARB process and the bonding characteristic of the interface was studied using scanning electricity microscope （SEM） and energy-dispersive spectroscopy （EDS）. The result indicated that accumulation cycles and diffusion annealing temperature were the most important factors for fabricating a Cu/AI composite material. The substrate aluminum was strengthened by MARB, and a high quality Cu/AI composite with sound interface was obtained as well.

Influence of Fabric Parameters on Microstructure,Mechanical Properties and Failure Mechanisms in Carbon-Fibre Reinforced Composites

The effects of fibre/matrix bonding, fabric density, fibre volume fraction and bundle size on microstructure, mechanical properties and failure mechanisms in carbon fibre reinforced composites （plastic and carbon matrix） have been investigated. The microstructure of unloaded and cracked samples was studied by optical microscopy and scanning electron microscopy （SEM）, respectively whereas the mechanical behaviour was examined by 3- point bending experiments. Exclusively one type of experimental resole type phenolic resin was applied. A strong fibre/matrix bonding, which is needed for high strength of carbon fibre reinforced plastic （CFRP） materials leads to severe composite damages during the pyrolysis resulting in low strength, brittle failure and a very low utilisation of the fibres strain to failure in C/C composites. Inherent fabric parameters such as an increasing fabric density or bundle size or a reduced fibre volume fraction introduce inhomogenities to the CFRP＇s microstructure. Results are lower strength and stiffness whereas the strain to failure increases or remains unchanged. Toughness is almost not affected. In C/C composites inhomogenities due to a reduced bundle size reduce strain to failure, strength, stiffness and toughness. Vice versa a declining fibre volume fraction leads to exactly the opposite behaviour. Increasing the fabric density （weight per unit area） causes similar effects as in CFRPs.

Dynamic Mechanical and Thermal Properties of Cross-linked Polystyrene/Glass Fiber Composites

Cross-linked polystyrene/glass fiber composites were fabricated using cross-linked polystyrene （CLPS） as matrix and E-glass fiber as the reinforcement. Surfaces of E-glass fibers were modified by vinyl triethoxysilane （VTES）, vinyl trimethoxysilane （VTMS） and γ-methacryloylpropyl trimethoxysilane （MPS）. The treated glass fibers were analyzed by fourier transform infrared spectroscopy （FTIR）. Dynamic mechanical thermal analysis （DMTA） and thermo-gravimetric analysis （TGA） were employed to investigate the effect of glass fibers surface modification on viscoelastic behavior and thermal properties. The morphology of fracture surfaces of various composites was observed by scanning electron microscopy （SEM）. The results revealed that these coupling agents were connected to the surfaces of the fibers by chemical bonding. Dynamic mechanical properties as well as thermal stability of the composites were improved considerablely, but to varying degrees depending on the fiber modification. The diversities of improvement of properties were attributed to the different interfacial adhesion between CLPS matrix and the glass fibers.