On the replacement of steel by NITINOL as coupling agent in automobile shaft

Automobile couplings generally fail due to excessive misalignment in shafts and torque overload which ultimately generates vibration in the assembly. These vibrations weaken the coupling structure and ultimately get transmitted to the shaft leading to fatigue failure. Additionally, the complexity in the design of standard coupling is related to lower durability. In this system, when the radial space is larger, it triggers a bulkier transmission. Shape memory alloy such as NITINOL is a special class of smart material that possesses superelasticity which means it can retain deformation of about 8%. This material has a high degree of strength, greater elastic and shear modulus than existing coupling materials, such as steel, and has unique vibration damping features. Coupling made of NITINOL is simple in design and requires lesser space with minimal maintenance. They provide higher durability and are much reliable in operation over a wide range of temperatures. This paper aims to review the NITINOL material used in coupling technology industries and the parameters governing its shape memory effect. The knowledge gathered from this work enables to further extend the technological contribution to NiTi coupling at large-scale production in the automobile sector with direct effect on longer life for the transmission system.