Search Results for metal casting design

This article discusses some of the factors that are linked directly to the casting design of ductile iron castings. It reviews the choice of molding process, application of draft, and patternmaker's allowance that should be taken into consideration in designing castings. The article describes the solidification shrinkage associated with the volume change that occurs during solidification, as well as strength and stiffness of ductile iron castings. It concludes with a discussion on the thermal deformation and residual stress in ductile iron castings.

This article discusses issues that impact a good casting design. The focus is on the casting design in general, and on sand and permanent mold aluminum casting in particular. The article examines the casting design process from a variety of design and processing perspectives. It summarizes several strategies for improving the traditional casting design process. The article also proposes some possible approaches for implementing these strategies. It presents a vision for the development of comprehensive casting design guidelines along with specific development objectives.

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.

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.

In many castings, functional requirements dictate that walls be uniform or nearly uniform in thickness. Many problems in producing castings having walls of uniform thickness are associated with the premature freezing of molten metal before all parts of the mold cavity have been filled. This article discusses the design problems and solutions of various castings, such as sand, shell mold, permanent mold, and investment castings, with illustrations.

This article provides a general introduction on casting processes and design techniques. It discusses the process steps and methods of the main categories of shape casting methods, namely, expendable molds with permanent patterns, expendable molds with expendable patterns, and metal or permanent mold processes. The article lists the general guidelines of geometry in casting design. It describes the three separate contractions that are a result of cooling: liquid-liquid contraction, solid-solid contraction, and liquid-solid contraction. Factors influencing the solidification sequence of simple shapes, such as T-sections, X-sections, and L-sections, are discussed. The article also presents an overview of geometric factors that influence heat transfer and transport phenomena. It concludes with a description of the structure and properties of castings.

Thin sections save weight and thus contribute to a more favorable strength-to-weight ratio. By requiring a smaller volume of metal, thin walls may also lower casting costs, particularly when an expensive alloy is being poured. This article discusses the design problems in thin-wall steel sand castings, thin-wall aluminum and magnesium castings, thin-wall permanent mold castings, and thin-wall investment castings, with schematic illustrations.

This article addresses the problems of designing isolated heavy sections that are functionally essential. It describes the two most efficient solutions to these problems over which the designer has control: providing flow and feed paths and reducing the mass of the isolated sections. The article concludes with a discussion on designs that reduce the mass of a remote section.

In most castings, there are junctions between intersecting component members. This article describes how defects can be eliminated in five types of junctions in steel castings, namely the L-junction, T-junction, V-junction, X-junction, and Y-junction. It also discusses design considerations for junctions in aluminum castings and provides a comparison between the T-junction and Y-junction. Finally, the article illustrates recommended methods for minimizing defects where sections of unequal thickness form a junction.

This article provides a comprehensive discussion on die casting alloy types and casting processes used in high-pressure die casting. It presents the advantages and disadvantages of high-pressure die casting and describes the product design for the process. The article concludes with information on the metal injection process of high-pressure die casting.

Cores are separate shapes, of sand, metal, or plaster, that are placed in the mold to provide castings with contours, cavities, and passages. Cored holes should be designed simply as the intended function of the casting permits. This article describes the designing of casting for the use of sand cores and to eliminate cores, with illustrations. It provides general rules for designing cored holes in investment castings. The article discusses the general principles of coremaking with illustrations. It concludes with a comparison between coring and drilling.

A gating system is the conduit network through which liquid metal enters a mold and flows to fill the mold cavity, where the metal can then solidify to form the desired casting shape. This article discusses various desirable design considerations for the gating system. Proper design of an optimized gating system will be made easier by the application of several fundamental principles of fluid flow. The article illustrates the Bernoulli's theorem, the law of continuity, and the effect of momentum. Most casting alloys are subject to the presence of particles that can deleteriously affect the physical properties and appearance of the casting. The article lists a variety of adverse effects of the particles. Ceramic filters, when correctly applied, can be relied on to trap particles before they can enter the casting cavity. The article concludes with information on the advantages and the types of the ceramic filters.

Sand mold and permanent mold casting are the major methods for shape casting of steels, with production closely split among green sand, chemically bonded sand, and permanent mold processes. This article describes key aspects of the steel casting process, including steel solidification characteristics, melting practices, melt treatment, and feeding of the molten steel into the mold used in steel foundries. It discusses the features of melting furnaces used in direct arc melting and induction melting. It reviews factors such as wall thickness and designing for avoidance of hot spots. The article explains the sand casting and permanent mold casting of steel. The process design and casting of thin sections are also discussed.

The designer of die casting tooling must balance the functional requirements of the part being cast with the cost, speed, and quality requirements of the process. In addition, attention must also be paid to the capacity and operating parameters of the casting machines being used and the need and economics of postprocessing. This article examines how design and materials selection address these diverse requirements of conventional die casting tooling. It focuses on the tooling for high-volume processes where the liquid or semisolid metal is forced into the die with high pressure and speed. The article also describes the functions of the tooling which involves supplying of molten alloy to the casting machine and injecting it into the die.

This article provides information on metals that can be cast in permanent molds. It describes the advantages, disadvantages, applications, and design of permanent castings. Following a discussion on the factors considered in mold design and material selection, the article details the application of mold coatings and examines the effects of major processing variables on mold life. The variables that determine mold temperature and measures for controlling it are reviewed, and the effects of short-term and long-term variables on the dimensional accuracy of permanent mold castings are explained. The article concludes with a discussion on the factors influencing the surface finish on permanent mold castings.

This article describes the melting process of casting metals used in hot chamber die casting. It discusses the design and capabilities of injection components, such as gooseneck, plunger, and cylinder. The article reviews the distinctions between hot and cold chamber processes. An example of a typical runner, gate and overflow configuration for faucet fixture casting is shown. Temperature control for die casting is also discussed. The article explains some ejection and post-processing techniques used for the hot chamber die casting: robotics, recycling, and fluxing.

This article describes the four basic steps of the purchasing process of cast components. These steps include defining requirements and developing a purchasing plan; requesting and evaluating bids from potential sources; selecting a source and negotiating contract terms; and carrying out the contract and pursuing continuous improvement. It provides guidance on purchasing cast components and explains specific issues and approaches that have proven to be useful in purchasing castings. The article presents a list of the most significant considerations when attempting to determine the overall cost and design requirements of a metal casting.

Gray cast iron is one of the most tolerant of metals when used with poorly designed filling systems. Good filling systems are necessary for the production of sound and acceptable ductile iron castings. This article presents an outline description of well-designed filling systems for all varieties of cast iron and all varieties of molds. It discusses the general conditions for the filling system layout, including the downsprue, sprue/runner junction, and runner. Both gray cast iron and compacted graphite iron exhibit a growth of graphite in direct contact with the liquid metal. The article concludes with a discussion on feeding of ductile iron.