Phase diagrams are graphical representations that show the phases present in the material at various compositions, temperatures, and pressures. This chapter begins with a section describing the construction of phase diagrams for the simple binary isomorphous system. A binary phase diagram can be used to determine three important types of information: the phases that are present, the composition of the phases, and the percentages or fractions of the phases. The chapter then describes the construction of one common type of binary phase diagram i.e., the eutectic alloy system. The major eutectic systems include the aluminum-silicon eutectic system and the lead-tin eutectic system. The chapter discusses the construction of eutectic phase diagrams from free energy curves. It also provides information on peritectic, monotectic, and solid-state reactions in alloy systems. The presence of intermediate phases is also described. Finally, a brief section provides some information on ternary phase diagrams.

This chapter begins by presenting a generic eutectic phase diagram and identifying critical points, lines, and features. It then describes the composition and properties of aluminum-silicon and lead-tin eutectic systems, the characteristics of eutectic morphologies, the solidification and scale of eutectic structures, and the competitive growth of dendrites and eutectic colonies or cells. It also examines the different types of precipitation structures that form during slow cooling cycles.

This chapter presents an overview and survey of solder alloy systems. Extensive reference is made to phase diagrams and their interpretation. The chapter describes the effect of metallic impurities on different solders. The chapter concludes with a review of the key characteristics of eutectic alloys and of the factors most effective at depressing the melting point of solders by eutectic alloying.

Phases are distinct states of aggregation of matter and one of the primary leverage points for understanding and applying materials. This chapter discusses the phase nature of metals and alloys, the concept of solid solutions, and the use of phase diagrams. It also describes some of the metallurgical effects of freezing or solidification, including the segregation of solutes and the formation of metal glasses.

This article examines the role of alloying in the production and use of lead and tin. It describes the various categories and grades of lead and lead-base alloys along with their nominal compositions and corresponding UNS numbers. It also discusses the composition and properties of lead used in battery grids, type metals, and bearings. It, likewise, discusses the use of tin in various types of solder and in bearings and provides composition and property data for application-specific designations and grades. The article also discusses the effect of impurities in tin-lead solders and the amounts and combinations in which they are found.

This chapter presents several materials and processes related to soldering technology. It first provides information on lead-free solders, followed by sections devoted to flip-chip processes, diffusion soldering, and modeling. Scanning acoustic microscopy and fine-focus x-ray techniques are also discussed. The chapter describes several evaluation procedures and tests developed to measure solderability and standards for process calibration. The chapter also describes the characteristics of reinforced solders, amalgams used as solders, and other strategies to boost the strength of solders. Further, the chapter considers methods for quantifying the mechanical integrity of joints and predicting their dimensional stability under specified environmental conditions. It discusses the effects of rare earth elements on the properties of solders. The chapter concludes with information on advanced joint characterization techniques.

This chapter discusses the compositions, properties, and applications of nonferrous metals, including zirconium, hafnium, beryllium, lead, tin, gold, silver, and platinum group metals. It also addresses fusible alloys and provides melting temperatures for several compositions.

Brazing and soldering processes use a molten filler metal to wet the mating surfaces of a joint, with or without the aid of a fluxing agent, leading to the formation of a metallurgical bond between the filler and the respective components. This chapter discusses the characteristics, advantages, and disadvantages of brazing and soldering. The first part focuses on the fundamentals of the brazing process and provides information on filler metals and specific brazing methods. The soldering portion of the chapters provides information on solder alloys used, selection criteria for base metal, the processes involved in precleaning and surface preparation, types of fluxes used, solder joint design, and solder heating methods.

This chapter introduces many of the key concepts on which metallurgy is based. It begins with an overview of the atomic nature of matter and the forces that link atoms together in crystal lattice structures. It discusses the types of imperfections (or defects) that occur in the crystal structure of metals and their role in mechanical deformation, annealing, precipitation, and diffusion. It describes the concept of solid solutions and the effect of temperature on solubility and phase transformations. The chapter also discusses the formation of solidification structures, the use of equilibrium phase diagrams, the role of enthalpy and Gibb’s free energy in chemical reactions, and a method for determining phase compositions along the solidus and liquidus lines.

This chapter discusses the phase transformations of peritectic alloy systems. It describes the processes involved with equilibrium and nonequilibrium freezing, the mechanisms of peritectic formation, and the resulting microstructures. It also discusses the formation of peritectic structures in iron-base alloys and multicomponent systems.

Aluminum casting alloy compositions parallel those of wrought alloys in many respects. However, because work hardening plays no significant role in the development of casting properties, the use and purposes of some alloying elements differ in casting alloys versus wrought alloys. This chapter provides information on specifications and widely used designation systems and alloy nomenclature for aluminum casting alloys. It describes the composition of seven basic families of aluminum casting alloys: aluminum-copper, aluminum-silicon-copper, aluminum-silicon, aluminum-silicon-magnesium, aluminum-magnesium, aluminum-zinc-magnesium, and aluminum-tin. The chapter discusses the effects of alloying elements on the properties of cast aluminum. It provides information on various alloys that are grouped with respect to their applications or major performance characteristics.

This chapter discusses the process, principles, and modeling of the diffusion brazing system. The applications of diffusion brazing to wide-gap joining and layer manufacturing are also discussed.

Materials used in joining, whether solders, fluxes, or atmospheres, are becoming increasingly subjected to restrictions on the grounds of health, safety, and pollution concerns. These regulations can limit the choice of materials and processes that are deemed acceptable for industrial use. The chapter addresses this issue with a focus on soldering fluxes. The chapter also describes factors related to soldering under a protective atmosphere, provides information on chemical fluxes for soldering of various metals, and discusses the processes involved in fluxless soldering processes.

Nonferrous metals are of commercial interest both as engineering materials and as alloying agents. This chapter addresses both roles, discussing the properties, processing characteristics, and applications of several categories of nonferrous metals, including light metals, corrosion-resistance alloys, superalloys, refractory metals, low-melting-point metals, reactive metals, precious metals, rare earth metals, and metalloids or semimetals. It also provides a brief summary on special-purpose materials, including uranium, vanadium, magnetic alloys, and thermocouple materials.

This chapter presents an overview of families of brazing alloys that one is likely to encounter in a manufacturing environment. It discusses the metallurgical aspects of brazing and includes a survey of brazing alloy systems. A discussion of deleterious and beneficial impurities is provided with examples. The chapter also describes the application of phase diagrams to brazing.

Liquid metals are frequently used as a heat-transfer medium because of their high thermal conductivities and low vapor pressures. Containment materials used in such heat-transfer systems are subject to molten metal corrosion as well as other problems. This chapter reviews the corrosion behavior of alloys in molten aluminum, zinc, lead, lithium, sodium, magnesium, mercury, cadmium, tin, antimony, and bismuth. It also discusses the problem of liquid metal embrittlement, explaining how it is caused by low-melting-point metals during brazing, welding, and heat treating operations.