This article reviews weldability of aluminum alloys and factors that affect weld performance. It first addresses hot tears, which can form during the welding of various aluminum alloys. It then presents comparison data from different weldability tests and discusses the specific properties that affect welding, namely oxide characteristics; the solubility of hydrogen in molten aluminum; and its thermal, electrical, and nonmagnetic characteristics. The article addresses the primary factors commonly considered when selecting a welding filler alloy, namely ease of welding or freedom from cracking, tensile or shear strength of the weld, weld ductility, service temperature, corrosion resistance, and color match between the weld and base alloy after anodizing. A number of factors, both global and local, that influence the fatigue performance of welded aluminum joints are also covered.

This chapter presents an overview of heat treating of nonferrous alloys. First, a brief discussion on the effects of cold work and annealing on nonferrous alloys is presented. This is followed by a discussion on the mechanisms involved in the more commonly used heat treating procedures for hardening or strengthening, namely solution treating and aging. Examples are presented for heat treating of two commercially important nonferrous alloys, one from the aluminum-copper system and one from the copper-beryllium system.

This chapter describes the factors that affect the corrosion performance of aluminum assemblies joined by methods such as welding, brazing, soldering, and adhesive bonding. The factors covered include galvanic effects, crevices, and assembly stresses in products susceptible to stress-corrosion cracking.

The nonferrous alloys described in this chapter include aluminum and aluminum alloys, copper and copper alloys, titanium and titanium alloys, zirconium and zirconium alloys, and tantalum and tantalum alloys. Some of the factors that affect the corrosion performance of welded nonferrous assemblies include galvanic effects, crevices, assembly stresses in products susceptible to stress-corrosion cracking, and hydrogen pickup and subsequent cracking. The emphasis is placed on the compositions, general welding considerations, and corrosion behavior of these alloys.

All materials are susceptible to corrosion or some form of environmental degradation. Although no single material is suitable for all applications, usually there are a variety of materials that will perform satisfactorily in a given environment. The intent of this chapter is to review the corrosion behavior of the major classes of metals and alloys as well as some nonmetallic materials, describe typical corrosion applications, and present some unique weaknesses of various types of materials. It also aims to point out some unique material characteristics that may be important in material selection, and discuss, where appropriate, the characteristic forms of corrosion that attack specific materials. The materials addressed in this chapter include carbon steels, weathering steels, and alloy steels; nickel, copper, aluminum, titanium, lead, magnesium, tin, zirconium, tantalum, niobium, and cobalt and their alloys; polymers; and other nonmetallic materials, including rubber, carbon and graphite, and woods.

This chapter provides a brief overview of nickel-iron-base, cobalt-base, and nickel-base superalloys, discussing their basic metallurgy and defining characteristics.

This chapter discusses some of the metallurgical factors that affect corrosion of weldments and describes a few considerations for selected nonferrous alloy systems: aluminum, titanium, tantalum, and nickel.

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.

This article discusses the general purpose of alloying and identifies some of the material properties and behaviors that can be improved by adding various elements to the base metal. It explains how alloying can make metals stronger and more resistant to corrosion and wear as well as easier to cast, weld, form, and machine. It also discusses some of the alloying techniques that have been developed to address problems stemming from dissimilarities between the base metal and alloying or inoculate material.

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 contains tables listing room-temperature tensile yield strength comparisons of metals and plastics and room-temperature tensile modulus of elasticity comparisons of various materials.

Superalloys are nickel, iron-nickel, and cobalt-base alloys designed for high-temperature applications, generally above 540 deg C. This chapter covers the metallurgy, composition, and properties of cast and wrought superalloys. It provides information on melting, heat treating, and secondary fabrication processes. It also covers coating technology, including aluminide diffusion and overlay coatings, and addresses the advantages and disadvantages of superalloys in various applications.