Shape Memory Alloy and Their Application in Industry 4.0

Abstract

Shape memory alloys (SMAs) hold significant importance due to their unique properties and their ability to address various engineering and technological challenges. Shape-memory alloys are metals that, even if they become deformed at below a given temperature, they will return to their original shape before deformation simply by being heated. Alloys with this unusual characteristic are used as functional materials in temperature sensors, actuators, and clamping fixtures. These metals also have a quality called superelasticity; like rubber, when it is bent or stretched, it will return to its original shape when the deforming force is removed. This characteristic of recovering shape despite substantial deformation is exploited in applications in industry 4.0. Shape memory alloys display two distinct crystal structures or phases. Temperature and internal stresses determine the phase that the SMA will attain. Martensite exists at lower temperatures, and austenite exists at higher temperatures. When a SMA is in martensite form at lower temperatures, the metal can easily be deformed into any shape. When the alloy is heated, it goes through transformation from martensite to austenite. In the austenite phase, the memory metal "remembers" the shape it had before it was deformed. From the stress vs. temperature graph, one can observe that at low stress and low temperature, martensite exists. At higher temperature and higher stress, austenite exists. Overall, SMAs are important because they offer solutions to a wide range of engineering challenges, enhance the performance of various systems, improve energy efficiency, and open up opportunities for innovation in smart industries. Their unique combination of properties makes them a valuable and versatile class of materials in the modern technological landscape.