Page 330 - 04. Subyek Engineering Materials - Manufacturing, Engineering and Technology SI 6th Edition - Serope Kalpakjian, Stephen Schmid (2009)

Qualitative Problems

structures (subassemblies), various other considerations (such as weldability,
machinability, and surface characteristics) also are important.
Within the limits of good performance, the economic aspects of casting are just as
important as the technical considerations. Factors affecting the overall cost are
the cost of materials, molds, dies, equipment, and labor-each of which varies
with the particular casting operation. An important parameter is the cost per
casting, which can justify large expenditures for large production runs using
automated machinery and computer controls.

KEY TERMS

Cast iron Flash Patternmaker’s shrinkage allowance
Compacted-graphite iron Hot spots Porosity
Design principles Machining allowance Shrinkage cavities
Draft Parting line Unit cost

BIBLIOGRAPHY

Abrasion-Resistant Cast Iron Handbook, American Foundry Cardelli, F., Materials Handbook: A Concise Desk Reference,
Society, 2000. 2nd ed., Springer, 2008.
Ammen, C.W, Metalcasting, McGraw-Hill, 2000. Casting Design and Performance, ASM International, 2009.
Analysis of Casting Defects, American Foundrymen’s Society, Clegg, A.]., Precision Casting Processes, Pergamon, 1991.
1974. Davis, ].R. (ed.), Cast Irons, ASM International, 1996.
ASM Handbook, Vol. 15: Casting, ASM International, 2008. Krauss, G., Steels: Heat Treatment and Processing Principles,
ASM Specialty Handbook: Cast Irons, ASM International, ASM International, 1990.
1996. Powell, G.W, Cheng, S.-H., and Mobley, C.E., jr., A
Bradley, E.F., High-Performance Castings: A Technical Fractography Atlas of Casting Alloys, Battelle Press,
Guide, Edison Welding Institute, 1989. 1992.
Bralla, ].G., Design for Manufacturability Handbook, Product Design for Die Casting, Diecasting Development
McGraw-Hill, 1999. Council, 1988.
Campbell, ]., Castings, 2nd ed., Butterworth-Heinemann, Rowley, M.T. (ed.), International Atlas of Casting Defects,
2003. American Foundrymen’s Society, 1974.
, Castings Practice: The Ten Rules of Castings, Steel Castings Handbook, 6th ed., ASM International, 1995.
Butterworth-Heinemann, 2004.

REVIEW QUESTIONS

l2.|. Why are steels more difficult to cast than cast irons? |2.6. Name the types of cast irons generally available, and
12.2. What is the significance of hot spots in metal casting? list their major characteristics and applications.
l2.3 What is shrinkage allowance? Machining allowance? I2.7. Comment on your observations regarding Fig. 12.4.
l2.4. Explain the reason for drafts in molds. l2.8. Describe the difference between a runner and a gate.
|2.5 What are light castings and where are they used most |2.9. What is the difference between machining allowance
commonly? and dimensional tolerance?

OUALITATIVE PROBLEMS

lZ.|0. Describe your observation concerning the design l2.I2. Do you generally agree with the cost ratings in
changes shown in Fig. 12.1. Table 12.6? If so, why?
I2.l I. If you need only a few castings of the same design, l2.|3. Describe the nature of the design differences shown
which three processes would be the most expensive per piece in Fig. 12.3. What general principles do you observe in this
cast? figure?