Effect of Grain Orientation on Properties

The degree of greiin orientation varies with the production process as mentioned above and has a considerable effect on the properties of molded graphite as shown in Table 5.5. 

Grade Particle Size mm Density g/crrP Specific Resistance O.cm Flexural Strength MPa Compress Strength MPa CTE (m/m °Cx10- ) (100-600°C) 

Notes CTE = coefficient of thermal expansion WG = with grain AG = across grain 

Materials and data from Cartxine of America,Graphite Materials Div., St. Marys, PA 

The extrusion process tends to align the particles in the extrusion flow direction and extruded graphite has a pronounced anisotropy, particularly in the strength and electrical properties. The isostatic-pressing process, on the other hand, results in a material that is much more uniform and is generally considerably stronger. 

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