Eventos Anais de eventos
COBEM 2017
24th ABCM International Congress of Mechanical Engineering
CONVERSION OF SUPERELASTIC NiTi SMA WIRES IN THERMOMECHANICAL ACTUATORS: A STUDY BASED ON HEAT TREATMENTS
Submission Author:
Daniel Jobson Alves Ribeiro , PB
Co-Authors:
Paulo César Sales da Silva, Carlos Jose de Araujo, Emerson da Trindade Marcelino, Daniel Jobson Alves Ribeiro
Presenter: Emerson da Trindade Marcelino
doi://10.26678/ABCM.COBEM2017.COB17-2057
Abstract
Shape Memory Alloys (SMA) are important smart materials that, after thermomechanical stimuli, present the phenomena of Shape Memory Effect (SME) and Superelasticity (SE). In both cases, large deformations can be recovered, upon heating for the SME and upon loading and unloading for the SE. NiTi SMA are currently employed in the medical and dental market in the form of tools and accessories for specific procedures. For these SMA, heat treatments are an adequate procedure for manipulating thermomechanical and functional (SME and SE) properties. Thus, this work aims to study the influence of annealing heat treatments on the thermomechanical behavior of NiTi SMA wires (originally superelastic). The factorial planning method was used to evaluate the influence of annealing temperature and time variables on some properties, as energy dissipation capacity, hardness, transformation temperatures, thermal hysteresis and transformation enthalpies. It was found that the annealing heat treatments carried out at 550°C are capable of converting NiTi SMA wires from the superelastic state to the actuator state, which was noticed by the occurrence of the Shape Memory Effect.
Keywords
Shape Memory Alloys, NiTi alloys, Heat treatments, Factorial planning
