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.

Grain refinement in aluminum casting alloys tends to reduce the amount of porosity and the size of the pores and to improve mechanical properties, especially fatigue strength. This article provides information on measurement of grain size in alloys and describes the mechanisms of grain refinement in aluminum casting alloys. It reviews the use of boron and titanium as a grain refiner for aluminum casting alloys. The article discusses the best practices for grain refinement in various aluminum casting alloys. These include aluminum-silicon casting alloys, aluminum-silicon-copper casting alloys, aluminum-silicon-copper casting alloys, aluminum-zinc-magnesium casting alloys, and aluminum-magnesium casting alloys. The article also examines the benefits of grain refinement in aluminum casting alloys.

Sand casting processes are typically classified according to the type of binder present in the molding sand mixture. This article discusses common sand casting processes and design considerations related to shape, gating, feeding, and pattern making methods. It describes the composition of sand and binder normally used, and provides information on the aluminum casting alloys produced. The article discusses precision sand casting and sand reclamation, and includes information on health and safety considerations.

Aluminum casting in steel and iron permanent molds is used widely throughout industry, and the vast majority of permanent mold castings are made of aluminum and its alloys. There are several methods used to cast aluminum in permanent molds. This article focuses on permanent mold casting with molten aluminum fed by gravity, low pressure, vacuum and centrifugal pressure, and squeeze casting. It discusses the major variables that affect the life of permanent molds, including pouring temperature, casting shape, cooling methods, heating cycles, storage, and cleaning. The article reviews the basic components of mold coatings: refractory fillers, binder, and carrier. Casting defects and suggested corrective actions for permanent mold casting are summarized in a table. The article concludes with a discussion on thin-wall permanent-mold castings.

Investment casting, in which molten metal is poured into hot molds, allows for the production of aluminum parts with extremely thin sections, knife edges and sharp detail. This article describes the various steps in the investment casting process, including patternmaking and dimensioning, the design and manufacture of shell molds, melting and casting methods, and postcasting operations such as knockout, core removal, and cleaning. It also addresses a wide range of design considerations, discusses casting defects, and provides several design examples.

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 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.

This article presents a detailed discussion on typical thermal treatment practices for hardening of various aluminum casting alloys. These practices are solution treatment, quenching or cooling, preaging, and artificial aging at an elevated temperature. The aluminum casting alloys considered here are: Al-Cu and Al-Cu-Mg (2xx) alloys, Al-Zn-Mg (7xx) alloys, Al-Si-Mg alloys, Al-Si-Cu, and Al-Si-Cu-Mg alloys.

This article aims to comprehensively review and summarize the material properties and engineering data for aluminum alloy castings and their many applications. The discussion focuses on conventional sand, permanent mold, and die castings as well as the premium engineered versions of some alloys. The article provides a summary of aluminum casting alloy designations of The Aluminum Association, the Unified Numbering System, and specific alloys considered premium strength by definition and by ASTM International and Aerospace Material Specifications. A distillation of data from published industry sources is given for a wide range of the properties and performance characteristics for topics such as: physical and thermophysical properties, typical and minimum mechanical properties, fatigue resistance, fracture resistance, and subcritical crack growth.

The strength of aluminum castings can be improved significantly by heat treatments, which control the size, shape, and distribution of the impurity elements in the casting. This article presents a discussion on the heat treatment of aluminum alloy castings, with a focus on the fundamental technical aspects involved in each process step. The intent is to convey a good understanding of the fundamental aspects of heat treatment. Typical heat treatments of aluminum casting alloys are presented in a table. The article describes the solution heat treatment, quenching, and preaging of Al-Si-Mg alloys, as well as the solution heat treatment and artificial aging of Al-Si-Cu-Mg casting alloys.

This article reviews the fatigue and fracture properties of aluminum alloy castings, specifically alloys A356 and A357/D357 (all-T6) and alloy A201-T7, from the perspective of both design and manufacturing considerations. In addition, it provides an overview of the roles played by microstructure, manufacturing processes, test conditions, and casting design in determining the fatigue and fracture properties of aluminum casting alloys.

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.