Banca de QUALIFICAÇÃO: JOAO LUCAS ARAUJO DA SILVA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : JOAO LUCAS ARAUJO DA SILVA
DATE: 28/02/2024
LOCAL: Qualificação por videoconferência
TITLE:

SYNTHESIS AND THERMOMECHANICAL EVALUATION OF COPPER-BASED SHAPE MEMORY ALLOY

KEY WORDS:

Shape memory effect, Martensitic transformation, Heat treatments, Martensite stabilization

PAGES: 59
BIG AREA: Engenharias
AREA: Engenharia de Materiais e Metalúrgica
SUMMARY:

Alloys with shape memory effect are widely known as smart materials due to their ability to respond to external stimuli, such as temperature changes, in a functional way, with characteristic behaviors. Furthermore, these alloys are capable of memorizing the shape presented before deformation and reversing it when subjected to thermal stimuli, as a result of an inherent non-diffusional phase transformation process, between martensite and a stable phase at high temperature (austenite). These materials can also be trained to assume one geometry when in the austenitic phase and another when in the martensitic phase. These behaviors result from phenomena known as simple shape memory effect, reversible shape memory effect, rubber-like behavior and superelasticity, which makes the use of these alloys dominate the field of applications, from the biomedical to the industrial sector, which require materials active and that present great thermoelastic behavior. Therefore, the present work aims to manufacture a copper-based quaternary alloy, by plasma fusion, which presents the shape memory effect, for subsequent microstructural characterization in the raw fusion, homogenized, betatized and aged states. For this, optical and scanning electron microscopy techniques, exploratory differential calorimetry, energy dispersive spectroscopy, X-ray spectroscopy, Xray diffraction will be used, in addition to the evaluation of mechanical behavior with microhardness techniques and dynamic mechanical analysis. Therefore, it is expected that the presence of cobalt, corresponding to 0.5% by mass, as a quaternary element in the worked system, promotes grain refinement and, thus, improves mechanical properties such as ductility and damping capacity, without inducing the formation of precipitates that hinder the mobility of the transformation interfaces, causes changes in the temperatures of the shape memory effect and modifies the thermoelastic behavior of the alloy. Furthermore, it is expected that the thermal aging treatment applied will reduce the levels of voids resulting from the betatization process and, thus, reduce the effects of martensite stabilization, which is harmful to the applications of these materials.

COMMITTEE MEMBERS:
Externo ao Programa - 2227254 - CEZAR HENRIQUE GONZALEZ - nullInterna - 3218488 - DAYANNE DINIZ DE SOUZA
Interno - 2296912 - OSCAR OLIMPIO DE ARAUJO FILHO
Presidente - 2154866 - TIAGO FELIPE DE ABREU SANTOS