Fundamentals of Materials Science and Engineering: An Integrated Approach, 3e

GTBL042-11 GTBL042-Callister-v3 October 4, 2007 11:59

2nd Revised Pages

440 • Chapter 11 / Phase Transformations

Figure 11.38

Diagram illustrating the shape memory effect. The insets are schematic representations of the crystal structure

at the four stages.

and

denote temperatures at which the martensitic transformation begins and ends. Likewise for the

austenite transformation,

and

represent beginning and end transformation temperatures. (Adapted from BALL, Philip;

MADE TO MEASURE

.

1997 Princeton University Press. Reprinted by permission of Princeton University Press.)

©

A

f

A

s

M

f

M

s

Austenite phase

Martensite phase(heavily twinned)

Austenite phase

1 2

4

3

M

s

M

f

Af As

Temperature

Martensite phase

(deformed)

Cool down

Heat up

Deform