Page 315 - Manufacturing Engineering and Technology - Kalpakjian, Serope : Schmid, Steven R.

Metal Casting:

Design, Nlaterials,

and Economics

° This final chapter on metal casting serves as a general guide to important con-
siderations regarding the interrelationships among product design, material,
and process selection, as well as economical methods of casting for specific
applications.
° The chapter describes in detail the design considerations for expendable-mold
and permanent-mold casting, and discusses the general guidelines for success-
ful casting operations.
and Good Casting
Designs 300 ¢ The characteristics and applications of the most common ferrous and nonfer-
rous alloys are then described.
° The chapter ends with a discussion of casting economics.

l2.l Introduction

In the preceding two chapters, it was noted that successful casting practice requires
the proper control of a large number of variables. These variables pertain to the
particular characteristics of the metals and alloys cast, method of casting, mold and
die materials, mold design, and various process parameters. The flow of the molten
metal in the mold cavities, the gating systems, the rate of cooling, and the gases
evolved all influence the quality of a casting.
This chapter describes general design considerations and guidelines for metal
casting and presents suggestions for avoiding defects. It also describes the character-
istics of the alloys that are commonly cast, together with their typical applications.
Because the economics of casting operations are just as important as the technical
aspects, this chapter also briefly outlines the basic economic factors relevant to
casting operations.

|2.2 Design Considerations in Casting

As in all manufacturing operations, certain guidelines and design principles pertaining
to casting have been developed over many years. Although these principles have been
established primarily through experience, analytical methods, process simulation and

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