Search Results for alloy systems

This chapter discusses the unique characteristics of isomorphous alloy systems. It begins with a review of the naming conventions for multi-component systems and the construction of a three-dimensional phase diagram for a two-component alloy system. It explains how phase diagrams can be constructed from time-temperature cooling curves and how they can be used to predict the phases present, their chemical compositions, and relative amounts. It also shows how phase diagrams can be modified to account for nonequilibrium cooling conditions.

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 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.

This chapter provides a brief overview of monotectic alloy systems and reactions. It begins by presenting a monotectic phase diagram and identifying important points, lines, and regions. It then describes the monotectic reactions that occur in copper-lead systems and the associated solidification structures. It also discusses the morphology of the microstructure produced during directional solidification and the classification criteria of low- and high-dome alloys.

Structurally differentiated intermetallic phases are important constituents in the microstructure of aluminum alloys, with the potential to influence properties, behaviors, and processing characteristics. These phases can form in aluminum-silicon alloys with transition metals (Fe, Mn, Ni, Cr, V, Ti) and with metals such as Mg and Cu. This chapter is a compilation of phase diagrams, microstructure images, and tables, providing information on more than 30 binary, ternary, and quaternary alloy systems associated with intermetallic phases in aluminum-silicon castings. Each section includes tabular information and data on the intermetallic phases in the aluminum corner of the equilibrium phase diagram, the characteristics of the crystal lattice of intermetallic phases, the chemical composition of the alloy intermetallic phases, and equilibrium reactions in the alloy system.

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 presents the Unified Numbering System (UNS) for metals and alloys.

This chapter discusses the construction, interpretation, and use of ternary phase diagrams. It begins by examining a hypothetical phase space diagram and several corresponding two-dimensional plots. It then describes one of the most basic tools of metallurgy, the Gibbs triangle, and explains how to construct tie lines to analyze intermediate compositions and phases. It also discusses the use of three-dimensional temperature-composition diagrams, three- and four-phase equilibrium phase diagrams, and binary and ternary phase diagrams associated with the iron-chromium-nickel alloy system.

This chapter concentrates on very low-temperature martensitic transformations, which are of great concern for cryogenic applications and research. The principal transformation characteristics are reviewed and then elaborated. The material classes or alloy systems that exhibit martensitic transformations at very low temperatures are discussed. In particular, the martensitic transformations and their effects in austenitic stainless steels, iron-nickel alloys, practical superconductors, alkali metals, solidified gases, and polymers are discussed.

This chapter is a compilation of beryllium phase diagrams, representing more than 25 binary alloy systems from beryllium-aluminum to beryllium-zirconium. Each diagram is presented along with a summary and source reference.

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.

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.