Eventos Anais de eventos
COBEM 2019
25th International Congress of Mechanical Engineering
ANALYSIS OF THE EFFECT OF HEAT TREATMENTS IN NITINOL SHAPE MEMORY ALLOYS
Submission Author:
Brenno Tavares Duarte , RJ
Co-Authors:
Brenno Tavares Duarte, Ricardo Alexandre Amar de Aguiar, Pedro Manuel Calas Lopes Pacheco
Presenter: Brenno Tavares Duarte
doi://10.26678/ABCM.COBEM2019.COB2019-1422
Abstract
Shape memory alloys (SMAs) are smart materials that are capable to recover strain when heated above their transformation temperature. The Nitinol alloy has stood out because of the high forces and large displacements that it can be submitted. A thermomechanical process is needed to shape it to the configuration for the desired application. The thermomechanical behavior of Nitinol SMAs suffers significant change due to material processing such as the introduction of microstructure defects with cold working and Ni3Ti4 precipitates generated with aging process. This study aims to analyse the effect of heat treatments in thermomechanical behavior of SMAs wires. Several heat treatments are applied on nitinol wires, and their behaviour are evaluated with a quasi-static tensile cyclic tests and Differential Scanning Calorimetry (DSC) tests. Quasi-static tensile tests are used to determinate the critical transformation stresses and characterize the mechanical behaviour of the alloy at room temperature Shape Memory Effect or Pseudoelastic). DSC tests are used to obtain the phase transformation temperatures, the latent heat of transformation and establish witch phase is stable at room temperature.
Keywords
Shape Memory Alloys, Heat treatment, Thermomechanical Behavior
