Engineering Innovation Podcast and Radio Series

Memory Metal

PostedSeptember 23, 2007

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Randy Atkins:  Metals are made of microscopic grains that are the key to giving them "memory."
Taher Saif:  It is not so much dependent on the type of metal, but just the size of the grains.

Randy Atkins:  Taher Saif, a University of Illinois engineer, says small grains bounce back when hit softly, but break when pushed too far, and larger grains, while harder to break, will deform permanently.  But if a car bumper with the just the right mixture gets hit…

Taher Saif:  Larger grains would allow the deformation and take the energy out, but the smaller grains would, over time, get the bumper back to where it came from.

Randy Atkins:  A little heat should speed up the process.  With the National Academy of Engineering, Randy Atkins, WTOP Radio.