Kutz M. Handbook of materials selection

Подождите немного. Документ загружается.

128 ALUMINUM ALLOYS

Fig. 16 Complex 3xx.x castings made by the investment casting processes provide the ability

to obtain exceptionally intricate detail and ﬁne quality.

3xx.x: Al–Si ⴙ Cu or Mg Alloys. The major characteristics of the 3xx.x

series are:

●

Heat treatable; sand, permanent mold, and die castings

●

Excellent ﬂuidity; high strength/some high-toughness alloys

●

Approximate ultimate tensile strength range: 19–40 ksi

●

Readily welded

The 3xx.x series of castings are one of the most widely used because of the

ﬂexibility provided by the high-silicon contents and its contribution to ﬂuidity

plus their response to heat treatment which provides a variety of high-strength

options. As a result, they are the best choice for large and complex castings

(Fig. 16). Further the 3xx.x series may be cast by a variety of techniques ranging

from relatively simple sand or die casting to very intricate permanent mold,

investment castings, and the newer thixocasting and squeeze casting technologies

(Fig. 17).

Among the workhorse alloys are 319.0 and 356.0/A356.0 for sand and per-

manent mold casting, with A356.0-T6 for such critical applications as automo-

tive wheels (Fig. 18). For die castings, 360.0, 380.0/A380.0, and 390.0 are the

most widely used. The newer squeeze/forge cast technologies have generally

employed A356.0-T6 and A357.0-T6.

Alloy 332.0 is also one of the most frequently used aluminum casting alloys

because it can be made almost exclusively from recycled scrap.

4 APPLICATIONS OF ALUMINUM ALLOYS 129

Fig. 17 Thixoformed A356.0-T6 and A357.0-T6 may be used for critical aircraft components.

Fig. 18 Automotive wheels are often cast A356.0-T6.

130 ALUMINUM ALLOYS

4xx.x: Al–Si Alloys. The major characteristics of the 4xx.x series are:

●

Nonheat treatable; sand, permanent mold, and die castings

●

Excellent ﬂuidity; good for intricate castings

●

Approximate ultimate tensile strength range: 17–25 ksi

Alloy B413.0 is notable for its very good castability and excellent weldability,

which are due to its eutectic composition and low melting point of 700

⬚C. It

combines moderate strength with high elongation before rupture and good cor-

rosion resistance. The alloy is particularly suitable for intricate, thin-walled, leak-

proof, fatigue-resistant castings.

These alloys have found applications in relatively complex cast parts for type-

writer and computer housings and dental equipment, and also for fairly critical

components in marine and architectural applications.

5xx.x: Al–Mg Alloys. The major characteristics of the 5xx.x series are:

●

Nonheat treatable; sand, permanent mold, and die

●

Tougher to cast; provides good ﬁnishing characteristics

●

Excellent corrosion resistance, machinability, surface appearance

●

Approximate ultimate tensile strength range: 17–25 ksi

The common feature of this group of alloys is good resistance to corrosion.

Alloys 512.0 and 514.0 have medium strength and good elongation and are

suitable for components exposed to seawater or to other similar corrosive en-

vironments. These alloys are often used for door and window ﬁttings, which can

be decoratively anodized to give a metallic ﬁnish or in a wide range of colors.

Their castability is inferior to that of the AI–Si alloys because of its magnesium

content and consequently long freezing range. For this reason it tends to be

replaced by 355.0/AJSi5Mg, which has long been used for similar applications.

For die castings where decorative anodizing is particularly important, alloy

520.0 is quite suitable.

7xx.x: Al–Zn Alloys. The major characteristics of the 7xx.x series are:

●

Heat treatable; sand and permanent mold cast (harder to cast)

●

Excellent machinability and appearance

●

Approximate ultimate tensile strength range: 30–55 ksi

Because of the increased difﬁculty in casting 7xx.x alloys, they tend to be

used only where the excellent ﬁnishing characteristics and machinability are

important. Representative application include furniture, garden tools, ofﬁce ma-

chines, and farming and mining equipment

8xx.x: Al–Sn Alloys. The major characteristics of the 8xx.x series are:

●

Heat treatable; sand and permanent mold castings (harder to cast)

●

Excellent machinability

4 APPLICATIONS OF ALUMINUM ALLOYS 131

●

Bearings and bushings of all types

●

Approximate ultimate tensile strength range: 15–30 ksi

Like the 7xx.x alloys, 8xx.x alloys are relatively hard to cast and tend to be

used only where their combination of superior surface ﬁnish and relative hard-

ness are important. The prime example is for parts requiring extensive machining

and for bushings and bearings.

4.2 Applications by Market Area

In the paragraphs that follow, a review will be made of the alloys often selected

for products in a number of the major markets in which aluminum is used.

Electrical Markets

The major products for which aluminum is used in electrical applications are

electric cable and bus conductor, where the high electrical conductivity (60%

IACS) makes aluminum a cost-effective replacement for copper products:

●

Electrical conductor wire—1350 where no special strength requirements

exist and 6201 where a combination of high strength and high conductivity

are needed.

●

Bus conductor—6101 (Fig. 2)

●

Electrical cable towers—6063 or 6061 extruded shapes

Building and Construction Markets

Building and construction encompasses those markets where architectural and/

or structural requirements come together. Such applications include residential

housing, commercial store fronts and structures, conference centers and areas

(i.e., long roof bay requirements), highway bridges and roadside structures, and

a variety of holding tanks and chemical structures (also considered under Petro-

leum and Chemical Industry Components). Among the choices:

●

Bridges and other highway structures—6063 and 6061 extrusions (Figs.

8, 9); 5083, 5083, and 5454 plate (Fig. 9)

●

Storefronts, curtain wall—6063 extrusions

●

Building sheet; siding—3005, 3105; 5005 sheet

●

Arena and convention center roofs—6061 extrusions with 5xxx alloy

sheet panels (Fig. 8)

●

Residential housing structures—6063 extrusions

●

Architectural trim—5257, 5657, and 6463

●

Composite wall panels—5xxx alloy sheet plus expanded polymers

Automobile, Van, SUV, Bus, and Truck Applications

Automotive structures require a combination of aluminum castings, sheet and

extrusions to cover all good opportunities to increase gasoline mileage and re-

duce pollutants. Among examples are the following:

132 ALUMINUM ALLOYS

●

Frame—5182 or 5754 sheet (Fig. 13a) or, for space frame designs, 6063

or 6061 extrusions

●

External body sheet panels where dent resistance is important—2008 and

6111(Fig. 13b)

●

Inner body panels—5083 and 5754

●

Bumpers—7029 and 7129

●

Air conditioner tubes, heat exchangers—3003 (Fig. 6)

●

Auto trim—5257, 5657, and 5757

●

Door beams, seat tracks, racks, rails, etc.—6061 or 6063

●

Hood, decklids—2036, 6016, and 6111

●

Truck beams—2014 and 6070 (Fig. 4)

●

Truck trailer bodies—5454, 5083, and 5456 (Fig. 4)

●

Wheels—A356.0 (Fig. 18), formed 5xxx sheet, or forged 2014-T6

●

Housings, gear boxes—357.0 and A357.0 (Fig. 16)

Aircraft and Aerospace Applications

Aircraft and aerospace applications require high strength combined with, de-

pending upon the speciﬁc component, high fracture toughness, high corrosion

resistance, and/or high modulus (sometimes all three). The result has been a

great number of alloys and tempers developed speciﬁcally for this market, as

illustrated by the examples below:

●

Space mirror—high-purity aluminum

●

Wing and fuselage skin—2024, alclad 2024, and 7050 plate or extrusions

(Fig. 3)

●

Wing structures—2024, 2124, 2314, and 7050 stiffened extrusions (Fig.

●

Bulkhead—2197, 7049, 7050, and 7175

●

Rocket tankage—2195, 2219, and 2419 (Fig. 5)

●

Engine components—2618

●

Propellers—2025

●

Rivets—2117, 6053

●

If high modulus is critical—Li-bearing alloys 2090, 2091, 2195, or 8090

●

If high fracture toughness is critical—2124, 2324, 7050, 7175, and 7475

●

For maximum fracture toughness—7475

●

If stress–corrosion resistance is important—7X50 or 7X75 in the T73-

type temper

●

If resistance to exfoliation attack is vital—7xxx alloys in the T76-type

temper

●

For welded construction, as for shuttle tanks—5456, 2219, and 2195

Marine Transportation

Many aluminum alloys readily withstand the corrosive attack of marine salt-

water, and so ﬁnd applications in boats, ships, offshore stations, and other com-

ponents that are immersed in saltwater:

4 APPLICATIONS OF ALUMINUM ALLOYS 133

●

Hull material—5083, 5383, 6063 and 6061 (Fig. 11)

●

Superstructure—5083 and 5456

●

Structural beams—5083, 5383, 6063, and 6061 (Fig. 11)

●

Off-shore stations, tanks—5083 and 5456 (Fig. 12)

Rail Transportation

Much as for auto and truck bodies, aluminum lends itself to railcar structural

and exterior panel applications:

●

Beams—2014, 6061, and 6070

●

Exterior panels—5456 and 6111

●

Tank cars—5454 and 5083

●

Coal cars—5454, 5083, and 5456 (Fig. 10)

●

Cars for hot cargo—5454

Packaging Applications

Packaging applications require either great ductility and corrosion resistance for

foil and wrapping applications or great strength and workability for rigid con-

tainer sheet applications, i.e., cans. Alloy choices include:

●

Aluminum foil for foods—1175 (Fig. 1)

●

Rigid container (can) bodies—3004 (Fig. 7)

●

Rigid container (can) ends—5182

Petroleum and Chemical Industry Components

The excellent combination of high strength combined with superior corrosion

resistance plus weldability makes a number of aluminum alloys ideal for chem-

ical industry applications, even some involving very corrosive ﬂuids:

●

Chemical piping—1060, 5254, and 6063

●

Pressure vessels (ASME code)—5083, 5086, 6061, and 6063

●

Pipelines—6061, 6063, and 6070

●

Cryogenic tankage—5052, 5083, 5454, 6063, and 6061

●

Containers for hydrogen peroxide—5254 and 5652

Other Markets

While not major markets in themselves, a variety of specialty products ﬁnd great

advantage in aluminum alloys:

●

Screw machine products—2011 and 6262

●

Appliances—5005 and 5052

●

Tread plate—6061

●

Weld wire—4043 (for welding 6xxx alloys), 5356, 5183, and 5556 (for

welding 5xxx alloys)

134 ALUMINUM ALLOYS

REFERENCES

1. American National Standard Alloy and Temper Designation Systems for Aluminum, ANSI H35.1-

1997, American National Standards Institute (ANSI), The Aluminum Association, Inc., Secretariat,

Washington, DC, 1997.

2. International Accord on Wrought Aluminum Alloy Designations, The Aluminum Association, Inc.,

Washington, DC, published periodically.

3. Aluminum Standards & Data (Standard and Metric Editions), The Aluminum Association, Inc.,

Washington, DC, published periodically.

4. The Aluminum Association Alloy and Temper Registrations Records:

a. International Alloy Designations and Chemical Composition Limits for Wrought Aluminum and

Aluminum Alloys, The Aluminum Association, Inc., Washington, DC, July, 1998.

Designations and Chemical Composition Limits for Aluminum alloys in the Form of Castings

and Ingot, The Aluminum Association, Inc., Washington, DC, January, 1996.

Tempers for Aluminum and Aluminum Alloy Products, The Aluminum Association, Inc., Wash-

ington, DC, February, 1995.

5. Standards for Aluminum Sand and Permanent Mold Casting, The Aluminum Association, Inc.,

Washington, DC, December, 1992.

6. Product Design for Die Casting in Recyclable Aluminum, Magnesium, Zinc, and ZA Alloys, Die

Casting Development Council, La Grange, IL, 1996.

7. Aluminum Casting Technology, 2nd ed., D. Zalenas (ed.), The American Foundrymens’ Society,

Inc., Des Plaines, IL, 1993.

8. The NFFS Guide to Aluminum Casting Design: Sand and Permanent Mold, Non-Ferrous Founders

Society, Des Plaines, IL, 1994.

9. D. G. Altenpohl, Aluminum: Technology, Applications and Environment, The Aluminum Associ-

ation Inc., and TMS, 1999.

Additional References

10. Aluminum Alloys—Selection and Application, The Aluminum Association, Washington, DC, De-

cember, 1998.

11. Aluminum and Aluminum Alloys, ASM Specialty Handbook, J. R. Davis (ed.), ASM International,

Materials Park, OH, February, 1994.

12. Heat Treater’s Guide—Practices and Procedures for Nonferrous Alloys, H. Chandler (ed.), ASM

International, Materials Park, OH, February, 1994.

13. Properties of Aluminum Alloys—Tensile, Creep, and Fatigue Data at High and Low Tempera-

tures, J. Gilbert Kaufman (Ed.), The Aluminum Association Inc., and ASM International, Ma-

terials Park, OH, December, 1999.

14. Aluminum Alloys for Cryogenic Applications, The Aluminum Association, Inc., Washington, DC,

1999.

15. Life-Cycle Assessments for Aluminum Alloy Products, The Aluminum Association, Inc., Wash-

ington, DC, February, 1996.

16. Aluminum for Automotive Body Sheet Panels, Publication AT3, The Aluminum Association,

Washington, DC, 1998.

17. Aluminum Automotive Extrusion Manual, Publication AT6, The Aluminum Association, Wash-

ington, DC, 1998.

18. J. Gilbert Kaufman, Introduction to Aluminum Alloys and Tempers, The Aluminum Association,

Inc. and ASM International Materials Park, OH, 2000.

19. J. Gilbert Kaufman, Fracture Resistance of Aluminum Alloys—Notch Toughness, Tear Resistance,

and Fracture Toughness, The Aluminum Association, Inc. and ASM International, Materials Park,

OH, 2001.

Design Rules and Guidelines

20. The Aluminum Design Manual, The Aluminum Association, Inc., Washington, DC, 2000.

21. M. L. Sharp, Behavior and Design of Aluminum Structures, McGraw-Hill, New York, 1993.

22. M. L. Sharp, G. E. Nordmark, and C. C. Menzemer, Fatigue Design of Aluminum Components

and Structures, McGraw-Hill, New York, 1996.

23. Fatigue Design Handbook, SAE AE-10, 2nd ed., Society of Automotive Engineers, Warrendale,

PA, 1988.

24. J. R. Kissell and R. L. Ferry, Aluminum Structures, A Guide to Their Speciﬁcations and Design,

Wiley, New York, 1995.

135

CHAPTER 5

COPPER AND COPPER ALLOYS

Konrad J. A. Kundig

Randolph, New Jersey

1 INTRODUCTION 135

2 STRUCTURE OF THE COPPER

INDUSTRY 136

3 COPPER ALLOY

DESIGNATIONS 137

4 PRODUCT FORMS 142

5 ELECTRICAL AND

ELECTRONIC WIRE

PRODUCTS 142

6 SHEET, STRIP, AND PLATE

PRODUCTS 143

6.1 Architecture 143

6.2 Electrical and Electronic Alloys 150

6.3 Industrial Products 165

7 TUBULAR PRODUCTS 166

7.1 Water Tube 166

7.2 Commercial Tube and Fittings 185

7.3 Alloy Tube 185

8 ROD, BAR, AND MECHANICAL

WIRE 185

8.1 Machined Products 186

8.2 Forgings 187

8.3 Mechanical Wire 187

9 CASTINGS 188

9.1 Casting Methods 188

9.2 Uses 198

9.3 Sleeve Bearings 199

10 COPPER IN HUMAN HEALTH

AND THE ENVIRONMENT 199

1 INTRODUCTION

Copper and copper alloys comprise one of the broadest and most versatile groups

of engineering materials. Almost 500 copper alloys are currently recognized in

the United States, and hundreds more are classiﬁed under international standards.

Copper alloys are also produced in all common product forms, further expanding

the possible choices.

The large selection may seem daunting, but choosing the correct alloy is

simpliﬁed by the fact that copper metals are normally chosen for particular

physical or mechanical properties, and alloys with the desired properties can

easily be sorted out. A need for very high electrical or thermal conductivity, for

example, generally points to one of the coppers or high-copper alloys, while

superior machinability suggests that a leaded alloy ought to be considered. There

are likewise alloys that are selected primarily for their superior corrosion resis-

tance, formability, castability, mechanical properties, biofouling resistance, and

biostatic behavior, among other things.

On the other hand, the main reason copper and it alloys are so widely used

is that they offer a better combination of useful properties than can be found in

HandbookofMaterialsSelection.EditedbyMyerKutz

136 COPPER AND COPPER ALLOYS

other materials. This fortunate circumstance reduces the level of compromise

needed to satisfy all design requirements satisfactorily.

The designer’s ﬁrst choice, however, is usually that of a suitable product form:

wire or rod; sheet, strip, or plate; castings; and so forth, and for that reason,

alloys listed in this chapter are grouped according to the forms in which those

alloys are customarily produced. Data is presented for a broad and representative

selection of alloys. Unfortunately, space constraints prohibit inclusion of data

for all currently registered alloys in all product forms and in all tempers. Com-

prehensive information on all alloys is available on line at The Copper Page

(http://www.copper.org), through the Copper Data Center (http://www.csa.com/

copperdata/), and from the Copper Development Association (CDA).

2 STRUCTURE OF THE COPPER INDUSTRY

Copper is truly a global metal, found in economic quantities in all continents

except Antarctica. Chile currently leads the world in copper production, having

passed the United States (which retains second place) in the early 1990s. Other

major copper-producing countries include Peru, Canada, Mexico, Poland, Zaire,

Zambia, Australia, Philippines, Indonesia, Papua New Guinea, and the Com-

monwealth of Independent States (CIS; former Soviet Union). The (former) U.S.

Bureau of Mines estimates that worldwide land-based copper resources stand at

1.6 billion metric tons (mt), with an additional 1.8 billion mt contained in deep-

sea nodules. Global copper depletion, once forecast as a looming threat, is now

seen as an unfounded concern.

Not all countries that mine substantial quantities of copper actually produce

commercial metal. Copper concentrates and an impure form of metal known as

blister copper are traded worldwide to countries having the smelters and reﬁn-

eries needed to complete the metal production process. Western Europe and

Japan, for example, mine little copper but produce signiﬁcant amounts for their

own use and for export.

Copper is a commodity metal, and the Comex and the London Metal

Exchange ﬁx published prices. The exchanges account for only a fraction of the

copper actually traded worldwide, however, and the bulk of trading takes place

between producers and users.

Major U.S. copper-mining states include Arizona, Utah, and Nevada plus, to

a lesser extent, New Mexico. Large deposits in the Upper Peninsula of Michigan,

once the primary source of domestic copper, have largely been mined out. The

U.S. copper-mining industry has consolidated considerably in recent years and

only three domestic producers—Phelps Dodge, Asarco Grupo Mexico, and Ken-

necott Utah Copper—can be considered major players in the sense that they

operate large mines on U.S. soil. On the other hand, these companies and others

have extensive holdings in copper-producing regions elsewhere in the world,

and, conversely, a number of foreign companies either have interests in, or

wholly own U.S.-based copper producers, including two of those named above.

Copper smelters, which produce blister copper from concentrates, are gen-

erally located near mines. Reﬁneries, where blister is puriﬁed to 99.9

⫹% pure

cathode copper through an electrolytic process, are somewhat more widespread,

although most are also found in the copper-mining states. Several large reﬁneries

are located in Texas.

3 COPPER ALLOY DESIGNATIONS 137

Copper products are produced by fabricators: wire mills, brass mills, foun-

dries, and metal powder plants. Their plants are found throughout the country.

The U.S. copper industry was once very much vertically integrated, but it has

become increasingly diversiﬁed and few fabricators now retain formal ties to

producers.

As explained below, copper wire and cable and other electrical products are

usually made from newly mined and reﬁned copper. Copper tube and alloy

products are made from a combination of reﬁned and scrap copper, as well as

copper alloy scrap. Copper is, in fact, among the most thoroughly recycled

industrial metals.

3 COPPER ALLOY DESIGNATIONS

In the United States and several other countries, copper and copper alloys are

classiﬁed under the Uniﬁed Numbering System for Metals and Alloys (UNS), a

system managed jointly by the American Society for Testing and Materials

(ASTM) and the Society of Automotive Engineers (SAE). CDA is responsible

for assigning numbers to copper alloys, which are identiﬁed by a ﬁve-digit code

preceded by the letter ‘‘C.’’ The codes are extensions of a previous and once

widely used three-digit numbering system, which was also administered by

CDA. Thus, for example, the alloy formerly known as copper alloy 360 by its

three-digit ‘‘CDA number’’ is now designated UNS C36000. It should be noted

that the UNS numbers are not speciﬁcations; they are merely standard desig-

nations for deﬁned compositions.

Copper alloys are sometimes also referred to by descriptive historical names

such as ‘‘free-cutting brass’’ and ‘‘naval brass.’’ Colorful as such names may be,

they can be ambiguous, and it is strongly recommended that alloys be called

out by their UNS numbers.

In addition to its UNS number, speciﬁcation of a copper or copper alloy

usually requires inclusion of a temper designation. Temper is a term that iden-

tiﬁes the metallurgical state of an alloy as well as the mechanical and physical

properties resulting from its processing history. Terms such as annealed, half-

hard, and precipitation heat treated, along with their coded abbreviations, are

listed in Tables 1 and 2 for wrought and cast alloys, respectively. The tables are

taken from ASTM B601. Mechanical property data tables in this chapter include

the most commonly speciﬁed tempers for the alloys listed. Data corresponding

to tempers not listed here may be found at http://properties.copper.org/ and in

publications available from CDA.

Copper Alloy Families. The copper metals are conventionally grouped into

several families according to similarities in composition, and hence, properties.

UNS numbers from C10100 through C79999 denote wrought (i.e., drawn, rolled,

extruded, or forged) alloys. Cast alloys are numbered from C80100 through

C99999.

The family identiﬁed as coppers include metals that have a designated min-

imum copper content of 99.3% or higher. Wrought coppers (wire, rolled prod-

ucts, extrusions, etc.) include UNS designations ranging from C10100 through

C15999, although all numbers are not in use. Cast coppers are numbered from