WELCOME. TECHNICAL SEMINAR ON “SMART MATERIALS”. INTRODUCTION HISTORY OF SHAPE MEMORY ALLOYS:. The first reported step towards discovery of shape memory effect were taken in 1930’s according to Otsuka and Wayman In a silver-cadmium alloy.
The first reported step towards discovery of shape memory effect were taken in 1930’s according to Otsuka and WaymanIn a silver-cadmium alloy.
Shape memory polymers have also been developed and become commercially available in late 1990’s.
Shape memory alloys or SMA's are metals that exhibit shape memory properties.
It allows materials possessing shape memory properties to return to their original shape after having suffered some form of deformation after they are heated to temperatures above their transformation temperature.
Smart materials are materials that have one or more properties that can be significantly changed in a controlled fashion by external stimuli, such as stress, temperature, moisture, ph, electric or magnetic fields.
TWO TYPES OF COMMON EFFECTS ARE:
ONE WAY EFFECT
TWO WAY EFFECT
ONE WAY EFFECT:
When a shape memory alloy is in its cold state, the metal can be bent or stretched and will hold those shapes until heated above transient temperature. Upon heating the shape changes to its original.
TWO WAY EFFECT:
A Material That Shows Shape Memory Effect During Both Heating And Cooling Is Called “Two Way Shape Memory”
BACK TO ORIGINAL SHAPE
“ Smart materials” are just starting to emerge from the laboratory but soon you can expect to find them in everything from laptops to concrete bridges.
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