Studying the Behavior of a Ni-Ti Shape Memory Alloy Wire

Abstract

Shape memory alloys (SMAs) are a special family of alloys that possess the ability to "remember" their shape and may even return to it when bent. At low temperatures, this alloy may seem to be plastically deformed; but, by increasing the temperature, this "plastic" strain might be repaired. The possession of these distinctive properties made these alloys very important and were widely employed in many technical fields, especially in the robotics, medical, safety and military sectors. This, in turn, encouraged scientists to test these alloys in order to learn more about how they behaved.  The study examines the behavior of an 80 cm long and 0.5 mm diameter Ni-Ti SMA wire sample via a series of experimental tests (chemical, mechanical, and electrical). This alloy's composition, as determined by chemical analysis, is 35.05% titanium and 64.95% nickel. The alloy wire's maximum tensile force and extension were 380 N and 10.8 mm, respectively, according to the findings of the mechanical tests; its maximum stress and strain were 1850 MP and 21.7%, respectively. According to the electrical test findings, the wire could support lifting up to 2 kg of weight when 0.2 A of current passed through it.