Search Results for economical coring

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.

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 begins with a schematic illustration of basic principles of sand molding. It discusses the general design factors, such as parting lines, location of radii, bosses and undercuts, and rib locations, of sand molding. The article schematically demonstrates alternative design solutions to molding and coring problems and describes the molding sequence. Draft refers to the amount of taper given to the sides of a pattern to enable it to be withdrawn easily from the mold. The article concludes with a simple example demonstrating the influence of a casting requirement on the direction of draft.

Properly designed beam-delivery optics is essential to quality of the beam acting on the workpiece and to the economics of the manufacturing process. This article describes the design considerations of laser beam delivery optics. It also reviews the manufacturing economics and presents two case studies of typical economic environments found in laser welding applications.

Cores are separate shapes of sand that are placed in the mold to provide castings with contours, cavities, and passages that are not otherwise practical or physically obtainable by the mold. This article describes the basic principles of coremaking and the types of core sands, binders, and additives used in coremaking. It discusses the curing of compacted cores by core baking and the hot box processes. The article provides an overview of the core coatings, assembling and core setting, coring of tortuous passages, and cores in permanent mold castings and investment castings. It also discusses the design considerations in coremaking to eliminate cores and compares coring with drilling.

This article discusses the categories and subcategories of shape casting processes. These include single-use processes such as sand, plaster, ceramic, and graphite molding; essentially unpressurized multiuse processes, such as permanent mold; and high-pressure metal mold methods, such as die casting, squeeze casting, and semisolid processing. The article contains tables that compare some of the typical capabilities of shape casting processes.

Induction hardening of geared parts used in aeronautic and aerospace industry is an important technology because of its one-piece flow, repeatability, energy efficiency, and tighter control of surface distortion than conventional carburizing. This article describes the requirements and characteristics of induction hardening of transmission parts, such as bearings, shafts, and different types of gears, including bevel gears, spur wheel gears, helical gears, and splines. It provides information on process monitoring and the economic aspects of induction hardening.

Resin transfer molding (RTM) and structural reaction injection molding (SRIM) are two similar processes that are well suited to the manufacture of large, complex, and high-performance structures. This article discusses the similarities and differences of RTM and SRIM processes and the unique design considerations with respect to the physical properties, geometry, surface quality, process economics, equipment, and tooling of a component that should be considered in choosing RTM or SRIM over other competing processes for fabricating reinforced components.

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.

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.

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 discusses the types of patterns used for a specific application such as loose patterns, match plate patterns, cope and drag patterns, and special patterns. It describes the principles of the patternmaking techniques used to make expendable molds and for metal casting processes such as die casting and permanent mold casting. The article reviews the pattern features and mold production considerations used in the pattern design, namely, parting line considerations, addition of gates and risers, core prints, and locating points. It examines the pattern allowances for ensuring a dimensionally correct final pattern. A variety of materials and advanced composite materials used in the manufacture of patterns are discussed. The article evaluates the factors influencing the selection of type of patterns for specific castings.

This article is a compilation of tables summarizing the fusion welding process. Included in the article is a table that presents the various fusion welding and cutting processes and their applications. Information on the general characteristics of arc welding processes is tabulated. The article also contains a list of the various criteria for selecting the suitable welding process for carbon steels.

Resin transfer molding and structural reaction injection molding belong to a family, sometimes denoted as liquid composite molding. This article provides information on the characteristics and automotive and aerospace applications of liquid composite molding. It reviews techniques that use hard tooling and positive (superatmospheric) pressures to produce structures. The techniques include vacuum-assisted resin injection, vacuum infusion, resin-film infusion, and injection-compression molding. The article provides an overview of the materials that are commonly used together with some of processing characteristics that are important to processing speed and part quality. It concludes with a discussion on design guidelines for the liquid composite molding.