Page 257 - Manufacturing Engineering and Technology - Kalpakjian, Serope : Schmid, Steven R.

23 Part II Metal-Casting Processes and Equipment

Engine block,
Alternator PISYOU
housing
Grill
Water pump,
pulleys Differential
Intake and l1°US'"9
exhaust
manifolds
Wheels,
disk brakes Brake
Transmission Door Cynnders
housing handles LOCKS
Brake rotors

FIGURE II.2 Cast parts in a typical automobile.

Met l-casting processes

Expandable mold Permanent (mold l ingl e-crystal grow ng

I
' : :
Composite mold
5 5 5
Sand if i 4' Slush Single crystals for microelectronics
Shell Pressure Single-crystal turbine blades
Evaporative pattern Die Directional solidification
Plaster Centrifugal
Ceramic Squeeze
investment Semisolid

FIGURE II.3 Outline of metal-casting processes described in Part II.

As in all manufacturing operations, each casting process has its own characteris-
tics, applications, advantages, limitations, and costs. Casting processes are most often
selected over other manufacturing methods for the following reasons:

' Casting can produce complex shapes and can incorporate internal cavities
or hollow sections.
° Very large parts can be produced in one piece.
° Casting can utilize materials that are difficult or uneconomical to process by
other means.
° The casting process can be economically competitive with other manufactur-
ing processes.

Almost all metals can be cast in (or nearly in) the final shape desired, often requiring
only minor finishing operations. This capability places casting among the most
important net-shape manufacturing technologies, along with net-shape forging
(Chapter 14), stamping of sheet metal (Chapter 16), and powder metallurgy and
metal-injection molding (Chapter 17). With modern processing techniques and the
control of chemical composition, mechanical properties of castings can equal those
made by other manufacturing processes.