THE COMPOSITE HAS CHARACTERISTICS QUITE DIFFERENT FROM THOSE OF THE SEPARATE MATERIALS

摘要

Conventional materials are never as strong as we expect because they contain defects of various kinds which cannot be eliminated in practical manufacturing. The strength of bulk glass and other ceramics is determined not by their strong covalent bonds, but by the tiny pores or sharp cracks that exist on the surface or in the interior. The strength of any sample of a glass or ceramic is determined by the size of the largest defect or crack which it happens to contain, and the strength of the best bulk ceramic will rarely exceed about one thousandth of its theoretical strength.