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Casting ProcessesChapters 10 -12

Casting ProcessesChapters 10 -12

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Process Equipment and CostProcess Equipment and Cost

FoundryFurnaces• (previous video – Ludken)

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Types of Melting FurnacesTypes of Melting Furnaces

Figure 11.26 Two types of melting furnaces used in foundries: (a) crucible, and (b) cupola.

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Process OverviewProcess Overview

Produce part in single step (“near-net”shape)Can produce a wide variety of shapes and sizesComplex shapes are possibleInternal cavities are possible

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Six Basic FactorsSix Basic Factors

1. Mold cavity2. Melting process3. Pouring technique4. Solidification process5. Removal of casting6. Cleaning/finishing

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Permanent Mold CastingPermanent Mold Casting

Die casting

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Typical Cast PartsTypical Cast Parts

(a)

(c)

(d)

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Die-Casting AlloysDie-Casting Alloys

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Die-Casting DiesDie-Casting Dies

Figure 11.19 Various types of cavities in a die-casting die. Source: Courtesy of American Die Casting Institute.

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Cleaning & FinishingCleaning & Finishing

Remove coresRemove gates and risersRemove fins, flashClean the surfaceRepair defects.Tumbling machines

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Defects Defects

Metal projectsCavitiesDiscontinuitiesDefective surfaceIncomplete castingIncorrect dimensions or shapeInclusions (unwanted material)Porosity• Shrinkage/gas

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General Casting Design RulesGeneral Casting Design RulesDesign the part to cast easily.Select the correct casting processLocate the parting line carefullyLocate and design the gates, runners, sprues, screens and risersCheck for proper controls and good practices

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Design for CastingDesign for Casting

Avoid sharp cornersAvoid thin sectionsPlan for shrinkage effectsUse draftAllow material for machining