CHARACTERIZATION OF MECHANICAL PROPERTIES OF AN ALLOY WITH SHAPE MEMORY - NITINOL
Thomas dos Santos Oliveira1; Pedro Henrique Alves Martins1; Santhiagu Lucas Procópio1; Ubirajara Domingos de Castro1; Maria Aparecida Alves Martins2; Claysson Bruno Santos Vimieiro1
1 PUC-Minas; 2 Izabela Hendrix
doi:10.20906/CPS/COB-2015-0152
Resumo
Alloys with shape memory are materials that undergo a deformation after, have the ability to return to its size and shape when subjected to an appropriate heat treatment. Nitinol is a nickel-titanium alloy (NiTi) that has this feature. In robotics, researchers seek to continually develop orthotics using actuators with features and capabilities that enable playback of the functions of the various motor systems of the human body. These systems have intended to support or detain a body segment, prevent or correct deformities and assist or recover some motor function disability, aiming at improving the quality of life of these individuals. This work aims to characterize the mechanical properties of a wire of a shape memory alloy Nitinol (NiTi) to propose the development of a mechatronic system for an orthosis prototype to simulate the function of the muscles of a human limb to perform the movements of a joint. Microhardness tests were performed in the alloy to determine its strength and metallographic tests to analyze its microstructure. In addiction, we developed a device capable of performing extension and flexion tests using electrical current to set the maximum percentage of plastic deformation supported by alloy to return to its original state.
Palavras-chave: Memory shape; Nitinol; Mechanical properties