Banca de DEFESA: FILLIPE STEPHANY DE SOUZA VIRGOLINO

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : FILLIPE STEPHANY DE SOUZA VIRGOLINO
DATE: 07/07/2022
TIME: 09:00
LOCAL: Defesa por videoconferência
TITLE:

Development of Wave Spring Washers actuators with shape memory alloys 

KEY WORDS:

Liga com memória de forma, liga Ni-Ti-Cu, Arruelas, pré-carga, fundição de precisão, impressão 3D

PAGES: 125
BIG AREA: Engenharias
AREA: Engenharia Mecânica
SUMMARY:

The development of smart materials has grown intensely, with the various researches and advances that have allowed the use of these materials in the form of actuators, known as EMF actuators. The LMF are special metallic materials capable of recovering residual deformations of great intensity (on average around
8% in uniaxial traction), through a simple heating process. In this context, this work aimed to study aspects involved in the preparation, fabrication and characterization of an alloy (Ti50Ni50-XCux), with variation of copper contents, to verify its influence on microstructure, mechanical properties and resistance, in the application of copper. a wavy washer to generate force (maintaining the preload) applied to bearings, ensuring longer life. The study was carried out in Ti50Ni50-XCux alloys with five different compositions, with the addition of 5,10, 15, 20 e 25 at.% Cu. Two types of washer were chosen, one in sheet metal and the other in wire and with commercial dimensions. For their manufacture, precision casting processes were chosen: Plasma Skull Push-Pull (PSPP), and to cast the alloys and induction casting with centrifugal injection (FIC) to cast the washers, using resin molds made in 3D printing, which proved to be quite effective. Characterization tests were carried out to determine the thermal and mechanical properties of the alloys. The main results obtained were that the 5 alloys can be manufactured by the plasma casting process, and their washers also showed good results for working at temperatures above ambient in a preload system due to EMF, in the results of XRD, SEM and MO were contacted for the presence of some precipitates, the microhardness maps proved that the casting is homogeneous and the thermomechanical characterization indicated that with the increase of the copper content in the alloys, the transformation temperatures increased and the hysteresis decreased, another factor. was that the alloys
obtained phase transformation in only one stage B2-B19', something that makes these alloys have high potential for application in the manufacture of corrugated washers.

BANKING MEMBERS:
Presidente - 2154866 - TIAGO FELIPE DE ABREU SANTOS
Interno - 2296912 - OSCAR OLIMPIO DE ARAUJO FILHO
Interno - 1132272 - SEVERINO LEOPOLDINO URTIGA FILHO
Externo ao Programa - 2227254 - CEZAR HENRIQUE GONZALEZ
Externa ao Programa - 3100969 - NATHALIA BEZERRA DE LIMA
Externo à Instituição - ANDRÉ DE ALBUQUERQUE VICENTE - USP