Elements of physical metallurgy [antikvár]

Metallurgy is the broad field of the science and technology of metals. It is conveniently divided into two areas: physical metallurgy, which constitutes the subject of this book, and process metallurgy. Process metallurgy, sometimes called chemical metallurgy, deals with the extraction of metals from their ores and with the refining, alloying, and initial stage in production (such as a massive ingót of steel). Physcial metallurgy is concerned primarily with the products of process metallurgy and their mechanical, physical, and chemical properties. Useful combinations of properties in a given alloy are achieved by control of chemical composition and of "metallurgical structure", which includes such aspects as grain size, constituent particles, and perfection of crystalline structure. Operations such as mechanical working and heat treatment are employed to produce the desired metallurgical structure. This book, which treats the fundamentals of physical metallurgy, is intended for students in engineering and in science as well as for those whose major interest lies in metallurgy. Chapters 1 through 4 build a background for understanding mechanical properties. The treatment begins with somé essential concepts of crystal structure, including the bonding of atoms and the useful quantitative procedure of stereographic projection. The elastie behavior of metals is studied from the crystallographic viewpoint as well as by use of continuum mechanics. The elastie properties of dislocations, the basic imperfections in a crystalline structure, are explained in introductory sections of Chapter 3. This chapter gives a broad coverage of the nature and behavior of vacancies, dislocations, and crystal boundaries. Chapter 4 builds on the prévious subject matter in presenting the essential phenomena of plastic deformation and fracture. A section on tests of plastic properties summarizes the test procedures for tensile, hardness, impact, endurance, rupture, and creep tests of alloys.