This article discusses the composition, structures, properties, and behaviors of aluminum alloys and explains how they correspond to specific alloying elements. It begins with an overview of the general characteristics of wrought and cast aluminum alloys, the four-digit classification system by which they are defined, and the applications for which they are suited. It then explains how primary alloying elements, second-phase constituents, and impurities affect yield strength, phase formation, and grain size and how they induce structural changes that help refine certain alloys. The article also explains how primary alloying elements affect corrosion and wear behaviors and how they influence fabrication processes such as forming, forging, welding, brazing, and soldering.

Aluminum is the second most widely used metal in the world. It is readily available, offers a wide range of properties, and can be shaped, coated, and joined using a variety of methods. This chapter discusses some of the key attributes of wrought and cast aluminum alloys and the classifications, designations, and grades of available product forms. It also explains how aluminum alloys are used in aerospace, automotive, rail, and marine applications as well as in building and construction, electrical products, manufacturing equipment, packaging, and consumer durables such as appliances and furniture.

This chapter provides an overview of the alloy and temper designations adopted for aluminum cast and wrought products. It explains the naming system and how to identify the main alloying elements and basic strengthening mechanism from any given alloy and temper designation. The chapter provides additional detail on the strengthening and softening mechanisms that allow aluminum alloys to attain a range of engineering properties. The strength of aluminum alloys can be controlled by three methods: solid-solution hardening by alloying, work hardening by plastic deformation, and precipitation hardening with appropriate alloying and heat treatment.

This chapter describes aluminum applications in aircraft and space vehicles and the special alloys, tempers, and product forms required to meet the unique challenges of flight. It focuses on wrought alloys and products that comprise the bulk of aluminum aircraft structure. The chapter also provides a list of the aerospace alloys and their chemical compositions in common use as well as their application on aircraft.

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

Aluminum has many outstanding properties, leading it to be used for a wide range of applications. It offers excellent strength-to-weight ratio, good corrosion and oxidation resistance, high electrical and thermal conductivity, exceptional formability, and relatively low cost. This chapter examines the metallurgy, composition, processing, and mechanical properties of aluminum and its alloys, both cast and wrought forms. It also covers heat treating and basic temper designations, including annealed, work hardened, solution heat treated, and solution heated treated and aged. The chapter concludes with information on corrosion and oxidation resistance.

The discovery and use of materials have shaped civilization since ancient times. This chapter traces the history of the use of metals from hammered copper estimated to be 11,000 years old to the development of electrolytically refined aluminum in 1884. The discussion covers the advent of the Bronze Age, extraction of metals from their respective ores, and the discovery of modern metals such as chromium, vanadium, platinum, and titanium.

Aluminum generally has excellent resistance to corrosion and gives years of maintenance-free service in natural atmospheres, fresh waters, seawater, many soils and chemicals, and most foods. This chapter explains why aluminum and aluminum alloys are naturally resistant to corrosion and describes the conditions and circumstances under which their natural defenses break down. It discusses the causes and forms of corrosion observed in aluminum alloys and the effect of composition, microstructure, processing history, and environmental variables such as impurities, fluid flow, surface area, pressure, and temperature.

This article discusses the composition, properties, and behaviors of zinc and its alloys. It explains where cast and wrought zinc alloys are used, describes commercial designations and grades, and discusses the effect of various alloying elements on properties and performance.

This chapter describes the process steps in the production of smelter grade aluminum, the environmental issues with aluminum production, and the importance of recycling. It also provides a discussion on the refining, or Bayer, process and the smelting, or Hall-Héroult, process.

Forged aluminum products vary widely in their production methods and applications. The forging process allows for control of microstructure and directional properties, and their fatigue and fracture resistance are superior to shape castings. This chapter presents the types, equipment, process steps, alloys, and products of aluminum forging.

This chapter describes the attributes of aluminum products that are critical for key structural applications. It covers the selection criteria and evaluations performed by the aluminum supplier or customer: physical attributes, mechanical properties (tensile, fracture, and fatigue), and corrosion.

Aluminum is protected by a barrier oxide film that, if damaged, reforms immediately in most environments. Despite this inherent corrosion resistance, there are conditions where aluminum alloys, like many materials, are subject to the effects of stress-corrosion cracking (SCC). This chapter describes those conditions, focusing initially on the effects of alloying elements and temper on solution potential and how it compares to other metals. It then addresses the issue of intergranular corrosion and its role in SCC. It explains how factors such as stress loads, grain structure, and environment determine whether or not stress-corrosion cracking develops in a susceptible alloy. It also provides stress-corrosion ratings for many alloys, tempers, and product forms and includes information on hydrogen-induced cracking.

This chapter provides basic engineering information on aluminum alloys with an emphasis on their use in applications where weight is a significant design factor. It discusses the advantages and limitations of various types of aluminum along with their compositions, designations, and achievable strengths. It explains how some alloys are hardened through solution strengthening and cold working, while others are strengthened by precipitation hardening. It also describes production and fabrication processes such as melting, casting, rolling, forging, forming, extruding, heat treating, and joining, and includes a section on the causes and effects of corrosion and how they are typically controlled.

This article examines the composition and properties of magnesium and its alloys. It discusses alloy and temper designations, applications and product forms, and commercial alloy systems, and explains how alloying elements affect physical and mechanical properties, processing characteristics, and corrosion behaviors.

A large portion of cast and wrought product production is directed to the ground transportation market. Aluminum castings, extrusions, forgings, and rolled products all find wide application for trucks, trains, subways, and buses and are discussed in this chapter.

The case for using stainless steel in appliances of all types, whether they are commercial or residential, relates to it being able to provide the best value over the intended service life. This chapter describes some of the qualities in any material considered for food contact, namely chemical neutrality, biological neutrality, and cleanliness. A vast majority of stainless steel applications in commercial and residential equipment are also discussed.

This chapter provides basic concepts and background for customer-related manufacturing processes applied to aluminum products including forming, joining and welding, surface treatments, and machinability. It reviews the selection criteria, key testing regimes, and original equipment manufacturer (OEM) requirements. The chapter also presents examples that demonstrate the importance of choosing the correct alloy and temper to successfully meet the OEM fabrication criteria.

Aluminum alloy products offer architectural and building solutions that exploit the benefits inherent in this metal: light weight, excellent durability, low maintenance, and thermal management opportunities. This chapter discusses the major applications for aluminum building products and related competitive materials. The commonly used alloys and tempers and their performance benefits are outlined for extruded profiles, rolled sheet and foil, and die cast products.

Titanium castings are used in a wide range of aerospace, chemical process, marine, biomedical, and automotive applications. This chapter provides an overview of titanium casting and associated processes and how they compare with other manufacturing methods. It also discusses the role heat treating and its effect on the tensile properties of different titanium alloys.