Casting

Casting

A manufacturing process where liquid metal is poured into a mold to create a desired shape.

Foundry

A factory for making molds, melting metal, and casting parts.

Expendable Mold Processes

Casting methods where the mold is destroyed after the casting is completed.

Permanent Mold Processes

Casting methods that use molds which can be reused for multiple castings.

Advantages of Casting

Can create complex geometries and has no size limit.

Disadvantages of Sand Casting

Generally results in poor dimensional accuracy and surface finish.

Riser

A reservoir in a mold that supplies molten metal during solidification.

Draft

A taper on patterns or mold cavities that facilitates their removal.

Fluidity

The ability of molten metal to flow and fill a mold before solidifying.

Chill Zone

A region with fine equiaxed grains formed by rapid cooling at the mold wall.

Directional Solidification

A solidification process where areas freeze in a sequence to minimize voids.

Bernoulli's Theorem

Describes fluid flow energy conservation, relevant for calculating pouring velocity.

Green-sand Mold

A mold containing moisture at pouring time.

Shell Molding

A casting process that uses a thermosetting resin binder to hold sand together.

Investment Casting

Also known as lost-wax process, a precision casting technique.

Plaster Mold Casting

A casting process using plaster of Paris to create molds.

Die Casting

A permanent mold process where molten metal is injected under high pressure.

Hot-chamber Die Casting

A die casting method that uses a piston to inject low-melting-point metals.

Centrifugal Casting

A method that uses centrifugal force to distribute molten metal in a rotating mold.

Misrun Defect

Occurs when casting solidifies before completely filling the mold.

Thread Rolling

A cold working process to form threads on cylindrical parts using dies.

Swaging

A process that uses rotating dies to taper a workpiece radially.

Extrusion

Forcing metal through a die to create a uniform cross-sectional shape.

Wire Drawing

A process that pulls metal through a die to form wire.

Impact Extrusion

A high-speed cold extrusion process used for collapsible tubes.

Back Pressure

Needed in some extrusion processes to maintain control over the material flow.

Hot Rolling

A metalworking process that deforms materials at high temperatures.

Cold Working

Deforming metals at room temperature to increase strength through strain hardening.

Mold Shift Defect

Caused by the sidewise displacement of cope and drag in sand casting.

Wavy Edges Defect

Result of high friction in flat rolling processes.

Alligatoring

A defect in rolling caused by excessive deformation or surface sticking.

Camber in Rolling Mills

Compensates for roll bending to ensure uniform thickness.

Barreling in Forging

Occurs due to friction between the workpiece and die in open-die forging.

Flashless Forging

A type of forging without excess flash created, allowing for complete constraint of the work.

Coining

A flashless process to mint coins with precise, sharp details.

Upsetting

Forming heads on bolts and nails through pressure.

Hydraulic Forging Press

Equipment used in forging that operates at lower speeds compared to others.

Counterblow Hammer

Forging equipment that operates at high speeds, allowing for rapid deformation.

Seamless Tubes

Produced via roll piercing that exploits cracks in compressed bars.

Seamless tube manufacturing

Roll piercing is used to create these products by exploiting internal features.

Draft Angle in Sand Casting

Typical angle required to ease the release of a casting from the mold.

Machining Allowance

Extra material provided for machining to achieve required dimensions in a casting.

Precision Casting

Casting method known for its high accuracy and intricate detail.

Thick Sections in Casting Design

Should be used as the section where gates feed into the casting.

Shrinkage Cavity Defect

A void caused by solidification shrinkage in cast parts.

Visual Inspection in Casting

Method of checking for obvious casting defects without advanced tools.

Rolling Processes

A bulk deformation method that reduces material thickness with rolls.

Rolling Mill Types

Different setups including 4-high and tandem for various rolling applications.

Shape Rolling

Forming cross sections into shapes like I-beams during rolling.

Material Strength during Hot Work

Reduced strength allows for significant shape changes in hot working.

Non-uniform Thicknesses in Extrusion

Must be avoided in design to ensure better flow and fewer defects.

Sharp Corners in Extrusion Design

Should be minimized to allow for smoother flow during the process.

Die Wear in Cold Extrusion

Increases due to high friction without adequate lubrication.

Tube forming in Impact Extrusion

Often used for products like collapsible tubes.

Annealing in Wire Drawing

A process to relieve work hardening between successive dies.

Extruded Parts

Products created with specific cross-sections through extrusion.

Applications of Rolling

Used for over 90% of deformed material in various industries.

Dimensional Accuracy in Die Casting

Best among different casting methods, making it favorable for intricate designs.

Bulk Forming Processes

Operations that significantly alter the shape of metals like bars and slabs.

Temperatures in Forging

Hot working occurs at elevated temperatures to allow for easier deformation.

Forging Equipment Types

Includes hydraulic presses, hammers, and other specialized machinery.

Cold Drawing Process

Increases strength while creating wire and bar products with precise dimensions.

Machining Requirements in Forging

Machining may be needed to achieve close tolerances after forging.

Refractory Material in Casting

Used in making molds for metals requiring high temperatures.

Investment Casting Advantages

Allows for intricate designs and high precision in final products.

Casting Operations Steps

Involves making molds, melting metal, pouring, solidification, and finishing.

Fluid Flow in Casting

Essential for successful filling of molds during the pouring process.