This chapter reviews and provides data tables for the wide range of properties and performance characteristics that are possible with specific aluminum casting alloys and tempers. Properties and performance attributes addressed include casting and finishing characteristics; typical physical properties; typical and minimum (design) mechanical properties; fatigue strength; fracture resistance, including subcritical crack growth; and resistance to general corrosion and to stress-corrosion cracking. The chapter concludes with information on the properties of cast aluminum matrix composites.

This chapter begins with information on the historical development of aluminum alloy castings. It then covers the basic factors involved in the selection of a casting process. This is followed by sections describing the various categories of casting processes and their variants: expendable mold gravity-feed casting, nonexpendable (permanent) mold gravity feed casting, and pressure die casting. Next, the chapter describes the technologies used to produce premium engineered castings and when such castings may be relevant. The chapter concludes with descriptions of other process technologies used with castings, including metallurgical bonding, metal-matrix composites, and hot isostatic pressing.

This chapter discusses the advantages and disadvantages of metal matrix composites and the methods used to produce them. It begins with a review of the composition and properties of aluminum matrix composites. It then describes discontinuous composite processing methods, including stir and slurry casting, liquid metal infiltration, spray deposition, powder metallurgy, extrusion, hot rolling, and forging. The chapter also provides information on continuous-fiber aluminum and titanium composites as well as particle-reinforced titanium and fiber metal (glass aluminum) laminates.

This chapter discusses the ambient-temperature corrosion characteristics of aluminum metal-matrix composites (MMCs), including composites formed with boron, graphite, silicon carbide, aluminum oxide, and mica. It also discusses the effect of stress-corrosion cracking on graphite-aluminum composites and the use of protective coatings and design criteria for corrosion prevention.

Metal-matrix composites (MMCs) work at higher temperatures than their base metal counterparts and can be engineered for improved strength, stiffness, thermal conductivity, abrasion and/or creep resistance, and dimensional stability. This chapter examines the properties, compositions, and performance-cost tradeoffs of common MMCs, including aluminum-matrix composites, titanium-matrix composites, and fiber-metal laminates. It also explains how fiber-reinforced composites and laminates are made, describing both continuous and discontinuous fiber matrix production processes.

Metal-matrix composites can operate at higher temperatures than their base metal counterparts and, unlike polymer-matrix composites, are nonflammable, do not outgas in a vacuum, and resist attack by solvents and fuels. They can also be tailored to provide greater strength and stiffness, among other properties, in preferred directions and locations. This chapter discusses the processes and procedures used in the production of fiber-reinforced aluminum and titanium metal-matrix composites. It explains how the length and orientation of reinforcing fibers affect the properties and processing characteristics of both aluminum and titanium composites. It also provides information on fiber-metal laminates and the use of different matrix metals and reinforcing materials.

Engineers have many materials to choose from when dealing with weight-related design constraints. The list includes aluminum, beryllium, magnesium, and titanium alloys as well as engineering plastics, structural ceramics, and polymer-, metal-, and ceramic-matrix composites. This chapter provides a brief overview of these lightweight materials, discussing their primary advantages along with their properties, behaviors, and limitations.

Aluminum casting alloy compositions parallel those of wrought alloys in many respects. However, because work hardening plays no significant role in the development of casting properties, the use and purposes of some alloying elements differ in casting alloys versus wrought alloys. This chapter provides information on specifications and widely used designation systems and alloy nomenclature for aluminum casting alloys. It describes the composition of seven basic families of aluminum casting alloys: aluminum-copper, aluminum-silicon-copper, aluminum-silicon, aluminum-silicon-magnesium, aluminum-magnesium, aluminum-zinc-magnesium, and aluminum-tin. The chapter discusses the effects of alloying elements on the properties of cast aluminum. It provides information on various alloys that are grouped with respect to their applications or major performance characteristics.

The properties of cast iron are determined primarily by the form of carbon they contain, which in turn, is controlled by modifying compositions and cooling rates during casting. Certain alloys (such as Si, Al, Ni, Co, and Cu) promote graphite formation, while others (such as S, V, Cr, Sn, Mo, and Mn) promote the formation of cementite. This chapter examines the relative potencies of these alloys and their effect on microstructure. It covers the five most common commercial cast irons, including white, gray, ductile, malleable, and compacted graphite, describing their compositional ranges, distinguishing features, advantages, limitations, and applications.

This chapter consists of three parts. The first part provides data and guidelines for selecting materials and processing routes. It compares the basic properties of metals, ceramics, and polymers, identifies important measures of performance, and discusses manufacturing processes and their compatibility with specific materials. The chapter then presents general guidelines for selecting lightweight materials, and concludes with a review of lightweight metals, plastics, and composites used in automotive applications.

The commercial relevance of cast irons is best understood in the context of the iron-carbon phase diagram, where their composition places them near the eutectic point, which sheds light on why they melt at lower temperatures than steel and why they can be cast into more intricate shapes. This chapter examines these unique properties and how they are derived. It begins by describing the basic metallurgy of cast iron, focusing on the eutectic reaction. It explains how to control the reaction and thus properties of cast iron by overcooling and inoculation. The chapter also discusses composition, microstructure, heat treatments, and the classification and casting characteristics of white, gray, ductile, malleable, compacted graphite, and special cast irons.

This chapter describes the metallurgy of superalloys and the extent to which it can be controlled. It discusses the alloying elements, crystal structures, and processing sequences associated with more than a dozen phases that largely determine the characteristics of superalloys, including their properties, behaviors, and microstructure. It examines the role of more than 20 alloying elements, including phosphorus (promotes carbide precipitation), boron (improves creep properties), lanthanum (increases hot corrosion resistance), and carbon and tungsten which serve as matrix stabilizers. It explains how precipitates provide strength by impeding deformation under load. It also discusses the factors that influence grain size, shape, and orientation and how they can be controlled to optimize mechanical and physical properties.

This article discusses the composition and morphology of compacted graphite (CG) iron relative to that of gray and ductile iron. It explains that the graphite in CG iron is intermediate in shape between the spheroidal graphite found in ductile iron and the flake graphite in gray iron, giving it distinct advantages in a number of applications. The article also discusses the role of melt treatment elements and explains how alloying and heat treatment affect tensile strength, hardness, toughness, and ductility.

Lightning damage in polymer composites, as in metal structures, is manifested by damage at both the macroscopic or visual level and within the material microstructure. In addition to visual damage assessment, non-destructive inspection techniques are employed to detect damage within the composite part. This chapter describes the macroeffects of a lightning strike on composites and discusses the methods involved in the assessment of microstructural damage in composites.

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.

This article discusses the metallurgy and properties of ductile cast iron. It begins with an overview of ductile or spheroidal-graphite iron, describing the specifications, applications, and compositions. It then discusses the importance of composition control and explains how various alloying elements affect the properties, behaviors, and processing characteristics of ductile iron. The article describes the benefits of nickel and silicon additions in particular detail, explaining how they make ductile iron more resistant to corrosion, heat, and wear.

This chapter provides an overview of the microstructure-property relationships associated with aluminum-silicon alloys. It includes information on commercial designations and grades, phase compositions, solidification paths, alloying elements, and intermetallic phases. It also provides solubility data and maps out the topics covered in subsequent chapters in the book.

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.

The microstructure of superalloys is highly complex, with a large number of dispersed intermetallics and other phases that modify alloy behavior through their composition, morphology, and distribution. This chapter provides an overview of the most notable phases, including the matrix phase and geometrically and topologically close-packed phases, and describes how superalloy microstructure can be modified via heat treatments and directional solidification. It also discusses the role of carbides, borides, oxides, and nitrides and the detrimental effects of sulfocarbides.