Reasearch On Short Carbon Fiber Conductive Composites' Temperature Sensibility

With the fast development in electronic technology, more and more importance has been attached to conductive resin composite materials. The industrialized batch production of carbon fiber has promoted its wide use in the area of materials. In erosion circumstances, the composite materials produced by carbon fiber can not only substitute or metal materials in conductivity but also attain some other requirements of special applications. Therefore, studies on conductivity and mechanical sensibility of carbon fiber reinforced composite have gradually become one of the main streams in the study on resin composites.Carbon fiber has a small specific weight, high specific strength, resistant to high temperature, conductivity, thermal conductivity, corrosion resistance and other characteristics, Carbon fiber polymer matrix composites in our country has become high-tech application and the focus of the study. In recent years, at home and abroad started to study carbon fiber materials temperature sensitivity in temperature, can be used as protection components and the use Of heating elements, carry out carbon fiber composite thermo-sensitive research is necessary.A more efficient materials design can be achieved through the use of electrical conductivity models. The use of accurate models aids in the understanding of the mechanisms that control conductivity in these composites, and provide insight into the properties important to achieving desired conductivity levels. In addition, the use of models can reduce costly experimental work, as well as the consumption of materials, through the ability to target a desired conductivity level for the composite based on a set of calculations.Taking the carbon fiber reinforced resin matrix composite as the research objects, is thesis, through masses of experiments, has investigated the variability of composite conductivity in different affecting factors, on the basis of which some other relative performances including Ohm characteristic, temperature sensibility, and so on are also discussed. The relationship between carbon fiber and the resistivities of composites and the relationship beween temperature and the resistivities of composites were got by analyzing the experiments.The result of the analysis showed the volume expansion is a main factor in resulting in the composites' PTC behavior which is more sensitive and evident when the filler fraction is within the percolation region. Based on above-mentioned studies, we proposed the conductivity mechanism of short carbon fiber filled thermoset polymer composites and established a model based on the general effective media (GEM) equation. The experimental data fit the model well. And internal factors which influence the resistitities of resin matrix composites were discussed and investigated.