Page 191 - 04. Subyek Engineering Materials - Manufacturing, Engineering and Technology SI 6th Edition - Serope Kalpakjian, Stephen Schmid (2009)

|70 Chapter 6 Nonferrous Metals and Alloys: Production, General Properties, and Applications

6.l9. If aircraft, such as a Boeing 757, are made of 79% 6.22. The example in this chapter showed the benefits of
aluminum, why are automobiles made predominantly of making cars from aluminum alloys. However, the average
steel? amount of steel in cars has increased in the past decade. List
reasons to explain these two observations.
6.20. Portable (notebook) computers and digital cameras
can have their housing made of magnesium. Why?
6.2l. Most household wiring is made of copper wire. By
contrast, grounding wire leading to satellite dishes and the
like is made of aluminum. Explain the reason.

QUANTITATIVE PROBLEMS
|]6.23. A simply supported rectangular beam is 30 mm 6.26. Beverage cans usually are stacked on top of each other
wide and 1 m long, and it is subjected to a vertical load of in stores. Use the information from Problem 6.24, and, refer-
40 kg at its center. Assume that this beam could be made of ring to textbooks on the mechanics of solids, estimate the
any of the materials listed in Table 6.1. Select three different crushing load each of these cans can withstand.
materials, and for each, calculate the beam height that would |]6.27. Using strength and density data, determine the
cause each beam to have the same maximum deflection. minimum weight of a 900-mm long tension member that
Calculate the ratio of the cost for each of the three beams. must support 340 kg if it is manufactured from (a) 3003-O
6.24. Obtain a few aluminum beverage cans, cut them, and aluminum, (b) 5052-H34 aluminum, (c) AZ31B-F magne-
measure their wall thicknesses. Using data in this chapter and sium, (d) any brass alloy, and (e) any bronze alloy.
simple formulas for thin-walled, closed-end pressure vessels, |]6.28. Plot the following for the materials described in
calculate the maximum internal pressure these cans can with- this chapter: (a) yield strength vs. density, (b) modulus of elas-
stand before yielding. (Assume that the can is a thin-walled, ticity vs. strength, (c) modulus of elasticity vs. relative cost,
closed-end, internally pressurized vessel.) and (d) electrical conductivity vs. density.

SYNTHESIS, DESIGN, AND PROIECTS

6.29. Because of the number of processes involved in mak- high strength, high corrosion resistance, and high creep resist-
ing metals, the cost of raw materials depends on the condi- ance (all at elevated temperatures) had not been developed.
tion (hot or cold rolled), shape (plate, sheet, bar, tubing), and 6.32. Assume that you are the technical sales manager of a
size of the metals. Make a survey of the technical literature, company that produces nonferrous metals. Choose any one
obtain price lists or get in touch with suppliers, and prepare a of the metals and alloys described in this chapter, and prepare
list indicating the cost per 100 kg of the nonferrous materials a brochure, including some illustrations, for use as sales liter-
described in this chapter, available in different conditions, ature by your staff in their contact with potential customers.
shapes, and sizes.
6.33. Give some applications for (a) amorphous metals,
6.30. The materials described in this chapter have numer- (b) precious metals, (c) low-melting alloys, and (d) nano-
ous applications. Make a survey of the available literature in materials.
the bibliography, and prepare a list of several specific parts or 6.34. Describe the advantages of making products with
components and applications, indicating the types of materi-
multilayer materials. (For example, aluminum bonded to the
als used.
bottom of stainless-steel pots.)
6.3 I. Name products that would not have been developed to
their advanced stages (as we find them today) if alloys having