This article examines the role of alloying in the production and use of nickel and its alloys. It explains how nickel-base alloys are categorized and lists the most common grades along with their compositional ranges and corresponding UNS numbers. It describes the role of nearly 20 alloying elements and how they influence strength, ductility, hardness, and corrosion resistance. It also addresses processing issues, explaining how alloying and intermetallic phases affect forming, welding, and machining operations.

Nickel and nickel alloys have an excellent combination of corrosion, oxidation, and heat resistance, combined with good mechanical properties. Nickel alloys can be divided into alloys that combine corrosion and heat resistance, superalloys for high-temperature applications, and special nickel alloys. Corrosion- and heat-resistant nickel alloys include commercially pure and low-alloy nickels, nickel-copper alloys, nickel-molybdenum and nickel-silicon alloys, nickel-chromium-iron alloys, nickel-chromium-molybdenum alloys, and nickel-chromium-iron-molybdenum-copper alloys. Special nickel alloys include electrical-resistance alloys, low-expansion alloys, magnetically soft alloys, and shape memory alloys. This chapter discusses the metallurgy, nominal composition, properties, applications, advantages, and disadvantages of these alloys. It also provides information on cobalt wear-resistant alloys and cobalt corrosion-resistant alloys.

Stainless steels and nickel-base alloys are recognized for their resistance to general corrosion and other categories of corrosion. This chapter examines the effects of specific alloying elements, metallurgical structure, and mechanical conditioning on the corrosion resistance of these alloys. Some categories of corrosion covered are pitting, crevice, intergranular, stress-corrosion cracking, general, and high-temperature corrosion.

This chapter is dedicated mostly to the metallurgical effects on the corrosion behavior of corrosion-resistant alloys. It begins with a section describing the importance of alloying elements on the corrosion behavior of nickel alloys. The chapter considers the metallurgical effects of alloy composition for heat-resistant alloys, nickel corrosion-resistant alloys, and nickel-base alloys. This chapter also discusses the corrosion implications of changing the alloy microstructure via solid-state transformation, second-phase precipitation, or cold work. It concludes with a comparison of corrosion behavior between cast and wrought product forms.

This appendix is a collection of tables listing coefficients of linear thermal expansion for carbon and low-alloy steels, presenting a summary of thermal expansion, thermal conductivity, and heat capacity; and listing thermal conductivities and specific heats of carbon and low-alloy steels.

Magnesium occupies the highest anodic position on the galvanic series and can be subject to severe corrosion. The corrosion problem is due to the impurity elements iron, nickel, and copper. However, the use of higher-purity magnesium alloys has led to corrosion resistance approaching that of some of the competing aluminum casting alloys. This chapter begins with a general overview of magnesium metallurgy and alloy designations and moves on to discuss in detail the nominal compositions, mechanical properties, heat treatment, fabrication, and corrosion protection of magnesium casting alloys and wrought magnesium alloys. It also discusses the nominal compositions, properties, and applications of commercially pure zinc, zinc casting alloys, and wrought zinc alloys.

This article discusses the compositions, structures, and properties of the most common grades of soft magnetic metals and permanent magnet alloys. It explains how alloying additions and impurities affect the magnetic properties of these materials, which include commercially pure and phosphorus irons, low-carbon and silicon steels, ferritic stainless steels, and nickel-iron and iron-cobalt alloys.

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.

Nickel-base alloys are generally used in harsh environments that demand either corrosion resistance or high-temperature strength. This article first describes the general welding characteristics of nickel-base alloys. It then describes the weldability of solid-solution nickel-base alloys in terms of grain boundary precipitation, grain growth, and hot cracking in the heat-affected zone; fusion zone segregation and porosity; and postweld heat treatments. Next, the article analyzes the welding characteristics of dissimilar and clad materials. This is followed by sections summarizing the various types and general weldability of age-hardened nickel-base alloys. The article then discusses the composition, welding metallurgy, and properties of cast nickel-base superalloys. Finally, it provides information on the welding of dissimilar metals, filler metal selection for welding clad materials and for overlay cladding, service conditions during repair, and welding procedural idiosyncrasies of cobalt-base alloys.

Nickel-base alloys used for low-temperature aqueous corrosion are commonly referred to as corrosion-resistant alloys (CRAs), and nickel alloys used for high-temperature applications are known as heat-resistant alloys, high-temperature alloys, or superalloys. The emphasis in this chapter is on the CRAs and in particular nickel-chromium-molybdenum alloys. The chapter provides a basic understanding of general welding considerations and describes the welding metallurgy of molybdenum-containing CRAs and of nickel-copper, nickel-chromium, and nickel-chromium-iron CRAs. It discusses the corrosion behavior of nickel-molybdenum alloys and nickel-chromium-molybdenum alloys. Information on the phase stability and corrosion behavior of nickel-base alloys is also included.

This chapter covers the friction and wear behaviors of copper alloys. It describes the compositions and forms of copper available and their suitability for applications involving friction, different types of erosion, and adhesive and abrasive wear.

Copper is often used in the unalloyed form because pure copper is more conductive than copper alloys. Alloying elements are added to optimize strength, ductility, and thermal stability, with little negative effect on other properties such as conductivity, fabricability, and corrosion resistance. This chapter covers the classification, composition, properties, and applications of copper alloys, including brasses, bronzes, copper-nickel, beryllium-copper, and casting alloys. It also examines wrought copper alloys and pure coppers. The chapter begins with an overview of the copper production process and concludes with a discussion on corrosion resistance.

This chapter discusses the effects of metallurgical factors on the corrosion resistance of magnesium alloys. The factors are chemical composition, heat treating, grain size, and cold-work effects. The chapter describes the causes of corrosion failures in magnesium alloys, namely heavy-metal contamination, blast residues, flux inclusions, and galvanic attack.

This chapter provides a general overview of titanium and its versatility as an engineering material.