Strength of modified carbon-graphite composites

Composite materials are being more and more widely used in the nontraditional power generation fields, particularly in powerplants using the ecologically clean energy sources (solar, wind, and tidal plants). The less expensive composites are preferred. Requirements of a functional nature are usually imposed on the composites: high (or low) thermal conductivity and high electroconductive (or electroinsulative) properties. At the same time, many powerplant components act as load-carrying structures and require analysis of their mechnical reliability and service life. Because of the considerable intrinsic mass (for large structures) and the wind, snow, and wave loads with long periods of operation, the mechnical analysis is a critical part of the design process. Various modification techniques are used to obtain materials with the required combination of mechanical, thermophysical, and electrical properties on the basis of the inexpensive composites. These techniques include modification of the properties of the binders by selecting the curing technique and introducing additives to the binder, and also the use of composites containing a quite high percentage of modifiers - metallic powders, ferromagnetics, ferroelectrics, and so on. The authors have studied the influence of the modifiers on the mechanical properties of the carbon-graphite composites that are created on the basismore » of powdered carbon-graphites and phenolformaldehyde resins. Such composites are already used in the heat engineering field. The carbon-graphite materials are obtained from a mixture of pulverized coke and coal tar with subsequent pressing into rod or blocks, which are sintered at 1200{degrees}C in air-free furnaces.« less