N. F. Mott 
Atomic Structure and the Strength of Metals [PDF ebook] 
An Account for the Nonscientist of Recent Researches Aimed at Understanding Why Metals Have Their Characteristic Strength and Ductility

Atomic Structure and the Strength of Metals is a collection of prepared lectures presented at the 1956 Page-Barbour Lectures before the University of Virginia. These lectures are based in part on two lectures given in the University of Cambridge as part of a course designed to present some of the ideas of physics to students of the humanities. The first lecture explores the physics of metals, with a particular emphasis on the properties of metals and their relationship with the properties of atoms. The second lecture describes the behavior of the atoms in a piece of metal when it is bent or pulled out. This lecture highlights the strength of solid, which involves the study of the defects in the crystalline structure. The third lecture discusses the concept and experimental evidence of material dislocation. This lecture provides a model of a polycrystalline metal, in which boundaries between grains appear. This book is directed toward physics students and nonspecialists.