E-Book Overview
Requiring knowledge of the chemistry and physics of materials, this study relates the complete set of strength characteristics of constituent atoms to their electronic structures. The book uses classical and quantum mechanics (since both are needed to describe these properties) and begins with short reviews of each area. After the reviews, the three major branches of the strength of materials are divided into the following sections: the elastic stiffnesses; the plastic responses; and the nature of fracture.
E-Book Content
ELECTRONIC BASIS OF THE STRENGTH OF MATERIALS This book is the first to relate the complete set of strength characteristics to the electronic structures of the constituent atoms. These relationships require knowledge of both the chemistry and physics of materials. Also, the book uses both classical and quantum mechanics since both are needed to describe the properties of atoms. The book begins with short reviews of the two mechanics. Following these reviews, the three major branches of the strength of materials are given their own sections. They are: the elastic stiffnesses; the plastic responses; and the nature of fracture. Elastic deformation can be reduced to two pure types: volume changes, and shape changes (shears). The moduli (stiffnesses) associated with each of these can be quantitatively obtained by means of the Heisenberg Principle and the theory of polarizability. The analytic theories are simple enough to indicate the physical origins of these properties. The most important atomic properties are the valence electron densities, and the electronic polarizabilities. These lead to electron exchange forces, and photon exchange forces, respectively. Atomic, molecular, and plasmonic polarizabilities play important roles. The anomalously large shear stiffness of diamond is explained in terms of the distribution of electrons along the covalent bonds, re