Search Results for automating gate removal

After solidification and cooling, further processing and finishing of the castings are required. This article describes the general operations of shakeout, grinding, cleaning, and inspection of castings, with particular emphasis on automation technology. It illustrates the vertical core knockout machine and the A-frame core knockout machine and lists the advantages and disadvantages of these machines. The article describes the general factors in automated or manual gate removal process. It concludes with discussion on the various types of inspection, such as the liquid penetrant inspection, pressure testing, radiographic inspection, magnetic particle inspection, and ultrasonic inspection.

High-pressure die casting is a fast method for the net shape manufacturing of parts from nonferrous alloys. This article reviews the automation technologies for the different stages or steps of the process. These steps include liquid metal pouring, injection, solidification, die open, part extraction, die lubrication, insert loading, and die close. Some manual aspects of the operations, together with automation options, are discussed. The article describes finishing steps, such as finish trimming, detailed deflashing, shot blast cleaning, and quality checks. Automation of the postcasting process is also discussed.

Nearly two-thirds of the aluminum castings made in North America are produced using high-pressure die casting techniques. This article compares and contrasts traditional high-pressure die casting with an improved version that uses a vacuum to pull air out of the die in order to reduce porosity in as-cast parts. It begins by describing a typical cycle for a traditional cold-chamber die casting machine, using detailed illustrations to show how gas can become trapped in the liquid metal. It then presents various remedies, ultimately focusing on vacuum die casting for the production of high-integrity parts. In addition to vacuum technology, the article discusses casting alloys, dies, and cells, and describes some of the benefits of structural die castings.

Unlike gray iron, which contains graphite flakes, ductile iron has an as-cast structure containing graphite particles in the form of small, rounded, spheroidal nodules in a ductile metallic matrix. This article discusses the raw materials that are used for ductile iron production and outlines the most common and important requirements for controlling the composition of ductile iron. Treatment to produce ductile iron involves the addition of magnesium to change the form of the graphite, followed by or combined with inoculation of a silicon-containing material to ensure a graphitic structure with freedom from carbides. The article describes the methods of magnesium treatment, control of magnesium content, and inoculation. It concludes with a discussion on the metallurgical controls of ductile iron production.

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.

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.

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.

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.

This article discusses the general principles and advantages of countergravity mold filling. It details several production implementations that use differential pressure countergravity mold filling methods, namely the countergravity low-pressure air process, countergravity low-pressure vacuum process, countergravity low-pressure inert atmosphere process, countergravity pressure vacuum process, supported shell technique, loose sand vacuum process, and countergravity centrifugal casting process.

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.

This article discusses classification of foundry processes based on the molding medium, such as sand molds, ceramic molds, and metallic molds. Sand molds can be briefly classified into two types: bonded sand molds, and unbonded sand molds. Bonded sand molds include green sand molds, dry sand molds, resin-bonded sand molds, and sodium silicate bonded sand. The article describes the casting processes that use these molds, including the no-bake process, cold box process, hot box process, the CO2 process, lost foam casting process and vacuum molding process. The casting processes that use ceramic molds include investment casting, and plaster casting. Metallic molds are used in permanent mold casting, die casting, semisolid casting, and centrifugal casting.

This article describes the control of alloy composition and impurity levels in die casting of zinc alloys based on agitation, use of foundry scrap, and melt temperature and fluxing. It reviews the process considerations for the melt processing of the zinc alloys. The process considerations include the usage of furnaces and launder system, scrap return, inclusions in zinc alloys, fluxing of zinc alloys, and galvanizing fluxes. The article discusses the materials and lubricant selection, casting and die temperature control, and trimming process used in hot chamber die casting for zinc alloys. It also reviews other casting processes for zinc alloys, such as sand casting, permanent mold casting, plaster mold casting, squeeze casting, and semisolid casting.

This article describes part selection, feedstock (powders and binders) characteristics and properties, tool design, and material and tooling for fabrication of metal powder injection molding (MIM) machines. It discusses the process parameters, operation sequence, molding machines, debinding techniques, consolidation (sintering) techniques, advantages, and limitations of MIM.

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.

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 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.

Aluminum casting alloys are the most versatile of all common foundry alloys and generally have the highest castability ratings. This article provides an overview of the common methods of aluminum shape casting. These include gravity casting, die casting, sand casting, lost foam casting, shell mold casting, plaster casting, investment casting, permanent mold casting, squeeze casting, semisolid forming, centrifugal casting, and pressure die casting. The article presents several different factors on which the selection of a casting process depends. It discusses gating and risering principles in casting. The article concludes with information on premium engineered castings that provide higher levels of quality and reliability than in conventionally produced castings.

This article discusses various molten-metal treatments, namely fluxing, degassing, and molten-metal filtration. It focuses on various molten-metal handling systems for transporting, holding, or delivering molten metal to the mold/die system. These include launders, tundishes, holding furnaces or transport crucibles, molten-metal transfer pumps, teeming ladles, and dosing and pouring furnaces.

This article provides an overview of the thixocasting process and discusses the concepts that are important to the practical application of this technology. The thixocasting process involves two casting processes. The first casting process is required to make the feedstock that must be reheated to achieve the structures necessary for casting. The second casting process combines billet sawing, reheating, and the actual injecting of material into the mold. The article focuses on these processes and provides information on rheological tests. It discusses some key design concepts used in thixocasting. The article illustrates the differences between a conventional high-pressure die-casting injection profile and the thixocasting injection profile used to produce the same part.

Injection molding is a process of forcing or injecting a fluid plastic material into a closed mold. The process generally has the advantages of being more readily automated and of permitting finer part details. Injection-molding compounds are thermoplastic or thermosetting materials and their composites that are specifically formulated for the injection-molding process. This article discusses the injection molding process, which includes the two basic categories of thermoplastic and thermoset injection molding, and lists the common thermoplastic and thermoset molding compounds and applications. It also describes the operation of the different types of injection molding machines as well as mold design and process controls. The article also describes the selection of injection-moldable thermosets, and provides an overview of part performance, properties, blowing agents, and aesthetic concerns related to thermoplastic structural-foam injection molding.