This chapter describes the mechanisms, characteristics, and prevention of intergranular and exfoliation corrosion in various aluminum alloys. It discusses susceptible alloys and recommended tempers and presents several examples of exfoliation in aircraft components. It also explains how the two forms of corrosion are related to stress-corrosion cracking.

This chapter describes the use of standardized tests to determine the susceptibility of aluminum alloys to specific forms of corrosion, including pitting, intergranular corrosion, filiform corrosion, exfoliation corrosion, and stress-corrosion cracking.

This chapter first covers some basic principles of electrochemical corrosion and then some of the various types of corrosion. Some of the more common types of corrosion discussed include uniform corrosion, galvanic corrosion, pitting, crevice corrosion, erosion-corrosion, cavitation, fretting corrosion, intergranular corrosion, exfoliation, dealloying corrosion, stress-corrosion cracking, and corrosion fatigue. The chapter discusses the processes involved in corrosion control by retarding either the anodic or cathodic reactions. The rate of corrosion is reduced by conditioning of the metal, by conditioning the environment, and by electrochemical control. Finally, the chapter deals with high-temperature oxidation that usually occurs in the absence of moisture.

This chapter describes the effects of metallurgical variables on the corrosion of aluminum alloys. Emphasis is placed on the effect of constituent particles on pitting corrosion of aluminum.

This appendix is a comprehensive collection of selected sources related to corrosion properties of materials and corrosion testing.

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.

This chapter discusses common forms of corrosion, including uniform corrosion, galvanic corrosion, pitting, crevice corrosion, dealloying corrosion, intergranular corrosion, and exfoliation. It describes the factors that contribute to stress-corrosion cracking, hydrogen embrittlement, and corrosion fatigue and compares and contrasts their effects on mechanical properties, performance, and operating life. It also includes information on high-temperature oxidation and corrosion prevention techniques.

Corrosion problems can be divided into eight categories based on the appearance of the corrosion damage or the mechanism of attack: uniform or general corrosion; pitting corrosion; crevice corrosion, including corrosion under tubercles or deposits, filiform corrosion, and poultice corrosion; galvanic corrosion; erosion-corrosion, including cavitation erosion and fretting corrosion; intergranular corrosion, including sensitization and exfoliation; dealloying; environmentally assisted cracking, including stress-corrosion cracking, corrosion fatigue, and hydrogen damage (including hydrogen embrittlement, hydrogen-induced blistering, high-temperature hydrogen attack, and hydride formation). All these forms are addressed in this chapter in the context of aqueous corrosion. For each form, a general description is provided along with information on the causes and the list of metals that can be affected, with particular emphasis on the recognition and prevention measures.

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 chapter provides an introduction to various forms of corrosion, namely uniform corrosion, localized corrosion, mechanically assisted degradation, environmentally induced cracking, microbiologically influenced corrosion, and metallurgically influenced corrosion.