Castability is a complex characteristic that depends on both the intrinsic fluid properties of the molten metal and the manner in which the particular alloy solidifies. This article discusses the practical aspects of solidification important to aluminum foundrymen. The primary focus is on the chemical segregation that occurs during freezing, because it determines the castability of the alloy. The article describes the two types of segregation, namely, microsegregation and macrosegregation. It discusses the effect of freezing range on castability of an alloy. The article lists the freezing range of a number of important alloys. It concludes with a discussion on castability of 2xx, 3xx, 4xx, 5xx, and 7xx alloys.

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.

Casting is one of the most economical and efficient methods for producing metal parts. In terms of scale, it is well suited for everything from low-volume, prototype production runs to filling global orders for millions of parts. Casting also affords great flexibility in terms of design, readily accommodating a wide range of shapes, dimensional requirements, and configuration complexities. This article traces the history of metal casting from its beginnings to the current state, creating a timeline marked by discoveries, advancements, and influential events. It also lists some of the major markets where castings are used.

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.

This article discusses the design parameters, operation, characteristics, properties, and advantages of various types of crucible furnaces, such as stationary, tilting, and movable furnaces. It also provides information on the application of the crucible furnaces.

This article focuses on aspects that are important for the commercial production of castings. It discusses the modification process in hypoeutectic and eutectic alloys that differ only in the relative volume fraction of primary aluminum and aluminum-silicon eutectic. The article explains how modification changes porosity formation in a casting. It describes the mechanisms responsible for silicon modification, as well as the modifications and changes in eutectic nucleation and the eutectic grain structure. The article reviews the usage of strontium in foundry practices. The growth of silicon eutectic is described to explain effects ancillary to silicon modification. The article also examines the effects of elements, such as phosphorus, antimony, bismuth, magnesium, boron, and calcium, on the silicon structure.

This datasheet provides information on key alloy metallurgy, foundry characteristics, processing effects on physical and mechanical properties, and applications of moderate-strength corrosion-resistant alloys 514.0 and 515.0.

In the handling of molten aluminum, it is fairly common to use filters as a part of the melting unit and in the gating and/or riser system. This article describes the methods of in-furnace and in-mold filtration, with an emphasis on the filtration of molten aluminum. It discusses the factors that influence the formation of inclusions. The article describes the three basic methods of mechanically removing or separating inclusions from molten metal. The methods include sedimentation, flotation, and positive filtration. The article provides a discussion on the types of molten-metal filters, including bonded-particle filters, cartridge filters, and ceramic foam filters. It lists the factors that are important in achieving optimum performance of any in-furnace filtering application. The article concludes with information on filtered metal quality and the methods of evaluation.

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.

Casting offers the cost advantages over other manufacturing methods for most components. This article reviews the aspects of castings with which designers should be familiar, as well as the methods used by foundries to produce high-integrity castings. It discusses the design concepts that designers and foundries can use to obtain maximum performance from cast parts. The article describes the effects of casting discontinuities on properties, including porosity, inclusions, hot tears, metal penetration, and surface defects. A discussion on hot isostatic pressing treatment of castings is also provided. The article concludes with information on solidification simulation and its use in designing castings.

This article provides general guidelines for casting design to provide progressive solidification, minimize heat concentration, eliminate cores, and prevent distortion. Casting design also affects tolerances. Casting tolerances depend on the alloy being poured, the size of the casting, and the molding method used. Designers can predict the effect of the design on the structure of the final part using solidification simulation models, namely finite element and finite difference models, and rapid prototyping. The article concludes with a short note on how the quality is assured in the foundry.

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.

Crucible furnaces, as compared to electric arc furnaces, are increasingly deployed in various melting practices due to their environmental and workplace friendliness and their process benefits. This article focuses on the application of induction crucible furnaces for melting and pouring operations in small-and medium-sized steel foundries, including aluminum, copper, and zinc industries. It also provides information on the process engineering benefits of melting and pouring operations.

This article describes the casting characteristics and practices of copper and copper alloys. It discusses the melting and melt control of copper alloys, including various melt treatments to improve melt quality. These treatments include fluxing and metal refining, degassing, deoxidation, grain refining, and filtration. The article provides a discussion on these melt treatments for group I to III alloys. It describes the three categories of furnaces for melting copper casting alloys: crucible furnaces, open-flame furnaces, and induction furnaces. The article explains the important factors that influence the selection of a casting method. It discusses the production of copper alloy castings. The article concludes with information on the gating and feeding systems used in production of copper alloy castings.

Aluminum alloys are primarily used for nonferrous castings because of their light weight and corrosion resistance. This article discusses at length the melting and metal treatment, structure control, sand casting, permanent mold casting, and die casting of aluminum alloys. It also covers the types and melting and casting practices of copper alloys, zinc alloys, magnesium alloys, titanium alloys, and superalloys, and provides a brief account on the casting technique of metal-matrix composites.

This article illustrates the basic components of dry and wet hearth reverberatory furnaces. It discusses stack melters that are used for aluminum metal casting, as they are efficient in sealing the furnace and using the flue gases to preheat the charge materials. The article describes the various factors for improving and maintaining furnace efficiencies. It explains the benefits of circulating molten metal in reverberatory furnaces and circulation methods.

The Al-Mg moderate-strength casting alloys 511.0, 512.0 and 513.0 are variations of alloy 514.0. Their most important characteristic is corrosion resistance, including exposure to seawater and marine atmospheres. This datasheet provides information on key alloy metallurgy, fabrication characteristics, processing effects on physical and mechanical properties, and applications of these alloys.

Dross, which is the oxide-rich surface that forms on melts due to exposure to air, is a term that is usually applied to nonferrous melts, specifically the lighter alloys such as aluminum or magnesium. This article describes dross formation and ways to reduce it, the economic implications of dross, and in-plant enhancement or recovery of dross. It discusses the influence of the melter type on dross generation and the influence of charge materials and operating practices on melt loss. Fluxing is a word applied in a broad sense to a number of melt-treating methods. The article also discusses the in-furnace treatment with chemical fluxes.

Aluminum casting alloys are the most versatile of all common foundry alloys and generally have the highest castability ratings. Aluminum alloy castings are routinely produced by pressure-die, permanent-mold, green and dry-sand, investment, and plaster casting. This article describes factors affecting the selection of casting process and the general designation system for aluminum alloys. It provides useful information on mechanical test methods, selection of proper test specimens for accurate test methods, characteristics of premium engineered castings, and advantages of hot isostatic pressing.