Chapter 11-

ISSUES TO ADDRESS...• How are metal alloys classified and how are they used?

• What are some of the common fabrication techniques?

• How do properties vary throughout a piece of material that has been quenched, for example?

1

• How can properties be modified by post heat treatment?

CHAPTER 11: METAL ALLOYSAPPLICATIONS AND PROCESSING

Chapter 11-2

Adapted from Fig. 9.21,Callister 6e. (Fig. 9.21 adapted from Binary Alloy Phase Diagrams, 2nd ed.,Vol. 1, T.B. Massalski (Ed.-in-Chief), ASM International, Materials Park, OH, 1990.)

Adapted from Fig. 11.1, Callister 6e.

TAXONOMY OF METALS

Fe3C

cementite

Metal Alloys

Steels

Ferrous Nonferrous

Cast Irons Cu Al Mg Ti<1.4wt%C 3-4.5wt%C

1600

1400

1200

1000

800

600

4000 1 2 3 4 5 6 6.7

L

austenite

+L

+Fe3C

ferrite+Fe3C

+

L+Fe3C

(Fe) Co, wt% C

Eutectic:

Eutectoid:0.77

4.30

727°C

1148°C

T(°C)

Steels<1.4wt%C

Cast Irons3-4.5wt%C

microstructure: ferrite, graphite cementite

Chapter 11-

Fe3C3Fe()+C(graphite)

Gray iron

Nodular (ductile) iron

White iron

Malleable iron: dark graphiterosettes (temper carbon) in an-ferrite matrix.

Metastable compound

If Si content > 1 wt%, then:

Chapter 11-

The true equilibrium iron-carbon phase diagram:for Si > 1 wt%