Page 173 - 04. Subyek Engineering Materials - Manufacturing, Engineering and Technology SI 6th Edition - Serope Kalpakjian, Stephen Schmid (2009)

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

TABLE 6.I
Approximate Cost-per-unit-volume for Wrought Metals and Plastics Relative
to the Cost of Carbon Steel

Gold 30,000 Magnesium alloys 4-6
Silver 600 Aluminum alloys 2-3
Molybdenum alloys 75-100 High-strength low-alloy steels 1.4
Nickel 20 Gray cast iron 1.2
Titanium alloys 20-40 Carbon steel 1
Copper alloys 8-10 Nylons, acetals, and silicon rubber” 1.1-2
Zinc alloys 1.5-3.5 Other plastics and elastomers* 0.2-1
Stainless steels 2-9

*As molding compounds.
Note: Costs vary significantly with quantity of purchase, supply and demand, size and shape, and other
factors.

TABLE 6.2
General Characteristics of Nonferrous Metals and Alloys
Material Characteristics
Nonferrous alloys More expensive than steels and plastics; Wide range of mechanical,
physical, and electrical properties; good corrosion resistance;
high-temperature applications
Aluminum Alloys have high strength-to-weight ratio; high thermal and
electrical conductivity; good corrosion resistance; good
manufacturing properties
Magnesium Lightest metal; good strength-to-Weight ratio
Copper High electrical and thermal conductivity; good corrosion
resistance; good manufacturing properties
Superalloys Good strength and resistance to corrosion at elevated temperatures
can be iron-, cobalt-, and nickel-based alloys
Titanium Highest strength-to-Weight ratio of all metals; good strength and
corrosion resistance at high temperatures
Refractory metals Molybdenum, niobium (columbium), tungsten, and tantalum; high
strength at elevated temperatures
Precious metals Gold, silver, and platinum; generally good corrosion resistance

6.2 Aluminum and Aluminum Alloys

The important advantages of aluminum (Al) and its alloys are their high strength-to-
weight ratios, resistance to corrosion by many chemicals, high thermal and electrical
conductivities, nontoxicity, reflectivity, appearance, and ease of formability and
machinability; they are also nonmagnetic. The principal uses of aluminum and its
alloys, in decreasing order of consumption, are in containers and packaging (aluminum
cans and foil), architectural and structural applications, transportation (aircraft and
aerospace applications, buses, automobiles, railroad cars, and marine craft), electrical
applications (as economical and nonmagnetic electrical conductors), consumer
durables (appliances, cooking utensils, and furniture), and portable tools (Tables 6.3
and 6.4). Nearly all high-voltage transmission Wiring is made of aluminum. In its struc-
tural (load-bearing) components, 82% of a Boeing 747 aircraft and 70% of a Boeing
777 aircraft is aluminum. The frame and the body panels of the new Rolls Royce