Smart Materials - A view towards Shape Memory Alloy

In the field of massive and complex manufacturing we are now in need of materials, with properties, that can be manipulated according to our needs. Smart materials are one among those unique materials, which can change its shape or size simply by adding a little bit of heat, or can change from a liquid to a solid almost instantly when near a magnet. These materials include piezoelectric materials, magneto-rheostatic materials, electro-rheostatic materials, and shape memory alloys (SMA’s). Shape memory alloys (SMA's) are metals, which exhibit two very unique properties, pseudo-elasticity (an almost rubber-like flexibility, under-loading), and the shape memory effect (ability to be severely deformed and then return to its original shape simply by heating). The two unique properties described above are made possible through a solid state phase change, that is a molecular rearrangement, in which the molecules remain closely packed so that the substance remains a solid. The two phases, which occur in shape memory alloys, are Martensite, and Austenite.

In this paper we have made a comparative study between SMA’s and other generally used materials or alloys, with the help of live examples (aircraft maneuverating, robotic muscles and human bone plates), and could conclude that SMA’s are superior to them in strength, biocompatibility and resistance point of view. Finally we have also suggested an idea, how the use of SMA’s in the mechanical couplings can make a powerful joint.