This article summarizes some general alloy groupings by application or major characteristics. The groupings include cast rotor, general-purpose, elevated-temperature, wear-resistant, moderate-strength, high-strength, and high-integrity die casting alloys and cast aluminum alloys bearings. A table lists selected applications for aluminum casting alloys.

There are a wide variety of furnace types and designs for melting aluminum. This article discusses the various types of furnaces, including gas reverberatory furnaces, crucible furnaces, and induction melting furnaces. It describes the classification of solid fluxes: cover fluxes, drossing fluxes, cleaning fluxes, and furnace wall cleaner fluxes. The article reviews the basic considerations in proper flux selection and fluxing practices. It explains the basic principles of degassing and discusses the degassing of wrought aluminum alloys. The article describes filtration in wrought aluminum production and in shape casting. It also reviews grain refinement in aluminum-silicon casting alloys, aluminum-silicon-copper casting alloys, aluminum-copper casting alloys, aluminum-zinc-magnesium casting alloys, and aluminum-magnesium casting alloys. The article concludes with a discussion on aluminum-silicon modification.

Gas porosity is a major factor in the quality and reliability of castings. The major cause of gas porosity in castings is the evolution of dissolved gases from melting and dross or slag containing gas porosity. Degassing is the process of removing these gases. This article describes the methods of degassing aluminum, magnesium, and copper alloys. It provides information on the sources of hydrogen in aluminum and gases in copper.

This article provides information on the applications of metal-matrix composites in engine components, brake system, and driveshaft. The components include pistons, cylinder liners, valves, pushrods, and connecting rods.

Metal matrix composites (MMCs) can be synthesized by vapor phase, liquid phase, or solid phase processes. This article emphasizes the liquid phase processing where solid reinforcements are incorporated in the molten metal or alloy melt that is allowed to solidify to form a composite. It illustrates the three broad categories of MMCs depending on the aspect ratio of the reinforcing phase. The categories include continuous fiber-reinforced composites, discontinuous or short fiber-reinforced composites, and particle-reinforced composites. The article discusses the two main classes of solidification processing of composites, namely, stir casting and melt infiltration. It describes the effects of reinforcement present in the liquid alloy on solidification. The article examines the automotive, space, and electronic packaging applications of MMCs. It concludes with information on the development of select cast MMCs.

Aluminum casting alloys are the most versatile of all common foundry alloys and generally have the highest castability ratings. This article discusses the designation and classification of aluminum casting alloys based on their composition and the factors influencing alloy selection. Alloys discussed include rotor alloys, commercial duralumin alloys, premium casting alloys, piston and elevated-temperature alloys, general-purpose alloys, magnesium alloys, aluminum-zinc-magnesium alloys, and bearing alloys. Six basic types of aluminum alloys developed for casting include aluminum-copper, aluminum-copper-silicon, aluminum-silicon, aluminum-magnesium, aluminum-zinc-magnesium, and aluminum-tin. The article also describes the main casting processes for aluminum alloys, which include die casting, permanent mold casting, sand casting (green sand and dry sand), plaster casting, and investment casting. In addition, the article discusses factors affecting the mechanical and physical properties, microstructural features that affect mechanical properties, the effects of alloying, and major applications of aluminum casting alloys.

This article begins with a discussion on the effects of alloying and impurity elements on the properties of aluminum cast alloys and their chemical compositions. It describes the various means of structural control, namely, chemistry control, control of element ratios based on the stoichiometry of intermetallic phases, and control of solidification conditions. The article discusses the modification and grain refinement of aluminum-silicon alloys by the use of modifiers and refiners to influence eutectic and hypereutectic structures in aluminum-silicon alloys. It provides information on foundry alloys for specific casting applications. The article concludes with a discussion on the heat treatment practices and properties of aluminum casting alloys.

This article presents typical wear applications for a variety of cast iron grades in a table. In general, wear is classified according to three major types: adhesive (frictional) wear (sliding and rolling) caused by contact of one metallic surface with another; abrasive wear caused by contact with metallic (shots, swarf) or nonmetallic abrasive materials; and erosive wear. The article discusses general wear characteristics of gray iron, compacted gray iron, and ductile iron. It provides information on the brake lining chemistry effects, graphite morphology effects, normal cast iron wear, local cast iron wear, and external abrasive effects on brake drums and disk brake rotors made of gray cast iron. The article concludes with a discussion on the application of cast iron for grinding balls.

Aluminum casting alloys are among the most versatile of all common foundry alloys and generally have high castability ratings. This article provides an overview of the common methods of aluminum shape casting. It discusses the designations of aluminum casting alloys categorized by the Aluminum Association designation system. The article summarizes the basic composition groupings of aluminum casting alloy and discusses the effects of specific alloying elements and impurities. The characteristics of the important casting processes are summarized and compared in a table. The article presents the advantages and disadvantages of green sand casting, permanent mold casting, semipermanent mold casting, and high-pressure die casting. A discussion on other casting processes, such as investment casting, lost foam, plaster mold casting, pressure casting, centrifugal casting, and semisolid casting, is also included.

Cast irons have been widely used by engineers in applications that require low cost, excellent castability, good damping capacity, ease of machining, and wear resistance. This article discusses the classification of wear for cast irons: adhesive wear, abrasive wear, and erosive wear. Typical wear applications for a variety of cast iron grades are listed in a table. The article reviews the general wear characteristics of gray irons, compacted graphite (CG) irons, and ductile irons. It discusses the typical compositions and properties of white and chilled iron castings. Gray cast iron is the dominant material for both brake drums and disk brake rotors. The article reviews brake lining chemistry effects, graphite morphology effects, and external abrasive effects on brake drums. It concludes with information on cast iron grinding balls.

This article is an atlas of fractographs that helps in understanding the causes and mechanisms of fracture of cast aluminum alloys and in identifying and interpreting the morphology of fracture surfaces. The fractographs illustrate the brittle fracture, microvoid coalescence, fatigue striations, and microstructure of these alloys. The components considered include fractured sand-cast carrier trays, broken extension-housing yokes, helicopter tail-rotor drive assemblies, fractured bell-crank fittings, chain-hoist hooks, and automotive connecting rods.

This article presents a detailed account on the process flow, composition, alternative sources, and the advancement of ironmaking, steelmaking and secondary steelmaking practices. Some steels, such as bearing steels, heat-resistant steels, ultrahigh strength missile and aircraft steels, and rotor steels have higher quality requirements and tighter composition control than plain carbon or ordinary low-alloy steels. The production of special-quality steels requires vacuum-based induction or electric remelting and refining capabilities. The article explores the types and characteristics of various steel manufacturing processes, such as ingot casting, continuous casting, and hot rolling. It provides an outline of specialized processing routes of producing ultralow plain carbon steels, interstitial-free steels, high strength low-alloy steels, ultrahigh strength steels, stainless steels, and cold-rolled products, and briefly explains the analytical techniques for liquid steels.

This article focuses on friction and wear of automotive and aircraft brakes. It provides a comparison of friction and wear behaviors, frictional characteristics, and frictional performance of the friction materials. The article describes the components of brake friction materials and the classifications of brake lining materials. It discusses the effect of formulation compositions and manufacturing processes and the effect of braking operation conditions. The article provides information on aircraft brake linings, which operate under a wide range of kinetic energy conditions. The morphology effect of graphite on automotive brake drum and disk is explained. The article also describes the characteristics of specific wear rates for both normal and local cast iron in automotive brake drums and disk rotors. It provides information on noises, vibrations, and harshness caused by brake pads. The article concludes with information on physical and chemical testing of brakes and toxicity of brake formulation and regulations.

Casting offers a great amount of component design flexibility. This article discusses six casting design parameters that drive the geometry of casting design from a process standpoint. It provides information on the design of junctions and addresses considerations of secondary operations in design. The article describes the factors that control casting tolerances and presents specific tips for designing castings with uniform wall thickness, unequal sections, thin sections, economical coring, functional packaging, and core design. The article provides a framework for analyzing all manners of manufacturing as possible conversion candidates for casting. It concludes with a discussion on different metalcasting design projects.

This article is an atlas of fractographs that covers nickel-base superalloys. The fractographs display the following: hydrogen-embrittlement fracture; segment of a fractured second-stage gas-turbine wheel; gas-producer turbine rotor cast; dendritic stress-rupture fracture surface; fatigue and creep fractures; simultaneous metallographic-fractographic evaluation; and effect of thermal cycling on fatigue fracture.

Aluminum fluxing is a step in obtaining clean molten metal by preventing excessive oxide formation, removing nonmetallic inclusions from the melt, and preventing and/or removing oxide buildup on furnace walls. This article discusses the solid fluxes and gas fluxes used in foundries. It reviews the classification of solid fluxes depending on their use and function at the foundry operation. These include cover fluxes, drossing fluxes, cleaning fluxes, and furnace wall cleaner fluxes. The article also examines the operational practices and applications of the flux injection in the foundries. It describes the applications of the aluminum fluxing such as crucible furnaces, transfer ladles, reverberatory furnaces, and holding/casting furnaces.

High-volume additive manufacturing (AM) for structural automotive applications, along the lines of economically viable technologies such as powder metallurgy, castings, and stampings, remains a lofty goal that must be realized to obtain the well-known advantages of AM. This article presents two key opportunities for AM related to automotive applications, specifically within the realm of metal laser powder-bed fusion: alloys and product designs capable of high throughput. The article also presents the general methodology of alloy development for automotive AM. It provides examples of unique designs for reciprocating components in elevated-temperature applications that are also exposed to demanding tribological conditions. The article also discusses the future of AM for automotive applications.

Aluminum alloys are widely used in engineered components because of their excellent strength-to-weight ratio. Their use in applications requiring wear resistance is more limited. One of the main limitations of aluminum alloys is the poor tribological behavior mainly due to their relatively low hardness, which favors large plastic deformation under sliding conditions. This article discusses the classes and mechanisms of wear in aluminum-silicon alloys, aluminum-tin bearing alloys, and aluminum-matrix composites; describes the effect of material-related parameters on wear behavior of these alloys; and reviews their applications in a variety of tribological applications in the automotive industry ranging from aluminum-tin alloys for plain bearings to alloys with hard anodizing for machine elements. Methods to improve wear resistance and alloy hardness are also discussed.