Eventos Anais de eventos
COBEM 2017
24th ABCM International Congress of Mechanical Engineering
Analysis of the effect of Heat Treatments in the manufacturing process of Shape Memory Alloy Springs
Submission Author:
Brenno Tavares Duarte , RJ
Co-Authors:
Ricardo Alexandre Amar de Aguiar, Pedro Manuel Calas Lopes Pacheco, Brenno Tavares Duarte
Presenter: Brenno Tavares Duarte
doi://10.26678/ABCM.COBEM2017.COB17-1533
Abstract
Shape memory alloys (SMAs) possess the capability to generate large displacements and forces when imposed to thermomechanical loadings, this outcome is due a phase transformation process during the loadings. Because this effect SMAs has been used in numerous applications. In those functions, several use SMA springs as vibration absorbers or as actuators. The spring manufacture process can lead to changes on the thermomechanical properties of the material, making it critical to understand how the heat treatments that create the springs affect its operation. Depending on the properties the SMA can have mainly two different behaviours: Shape memory effect, when is needed to heat the material to recover the deformation; or Pseudoelastic, when the deformation caused by the mechanical loading recovers as soon as the loading ceases. This study aims to experimentally establish how the heat treatments influence on the properties of SMA. Through a set of different heat treatments, the characterization will be carried out by quasi-static and DSC tests, using groups of the wire as received, wire after the heat treatment and the springs itself. From the DSC tests, will be detected the phase transformation temperatures and evaluated which phase is stable at room temperature. From the quasi-static tests, will be measured the transformation tensions of the SMA. Finally, the results will be analyzed and determined the optimal heat treatments for each desired behaviour.
Keywords
Shape Memory Alloy, Springs, Heat treatment
