Eventos Anais de eventos
COBEM 2023
27th International Congress of Mechanical Engineering
Manufacturing and Analysis of a Heat-Activated Staple Using Ti-Ni-Cu Shape Memory Alloy
Submission Author:
Anna Beatriz de Araújo Pereira , PB
Co-Authors:
Anna Beatriz de Araújo Pereira, Paulo César Sales da Silva, Ícaro Carvalho Dourado, Carlos Jose de Araujo
Presenter: Carlos Jose de Araujo
doi://10.26678/ABCM.COBEM2023.COB2023-0870
Abstract
Nickel-Titanium (Ni-Ti) Shape Memory Alloys (SMA), commercially known as NiTiNOL, have unique features like Shape Memory Effect (SME) and Superelasticity (SE). These features are due to solid-solid phase transitions between two phases, austenite and martensite. Austenite is stable at higher temperatures, while martensite is stable at lower temperatures. Additionally, these SMA have excellent corrosion resistance, biocompatibility, mechanical strength, and ductility. Moreover, their modulus of elasticity is more compatible with that of bone tissues, and they can exert a continuous and dynamic force. Therefore, they can be used for orthopedic applications such as staples and in the treatment of fractures, osteotomies, and arthrodesis of bones and tendons of the human or animal musculoskeletal system. Very recently, a new alloy 47Ti-32Ni-21Cu (% at.) was developed using the Artificial Intelligence Material Selection (AIMS) methodology. The unique features of this TiNiCu SMA include reduced thermal hysteresis and transformation temperature range, as well as excellent cyclic stability and actuation stress. In this work, we aimed to manufacture and analyze this TiNiCu SMA for possible application in heat-activated orthopedic staples. The 47Ti-32Ni-21Cu (% at.) SMA was manufactured using the electric arc melting process under an argon atmosphere. The prototypes of orthopedic staples were produced through rapid investment casting using resin models obtained by additive manufacturing. The respective ceramic molds of the staples were manufactured from the resin models. After sintering, the molds were filled with the alloy to create TiNiCu SMA staples. Finally, the post-processing stage involved finishing and heat treatment of the staples, followed by thermal characterization tests using Differential Scanning Calorimetry (DSC) technique. The clamp samples had a phase transformation temperature range of 15.8 °C and thermal hysteresis of approximately 10.5 °C. We conclude that it is possible to manufacture orthopedic staples prototypes with low thermal hysteresis using 47Ti-32Ni-21Cu (% at.) SMA and the process of rapid investment casting.
Keywords
Shape memory alloys (SMA), Ti-Ni-Cu alloys, Orthopedic staples, investment casting
