Banca de DEFESA: FERNANDA MAGALHÃES DE OLIVEIRA CAMPOS

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : FERNANDA MAGALHÃES DE OLIVEIRA CAMPOS
DATA : 05/12/2024
HORA: 08:00
LOCAL: meet.google.com/suc-wdxo-zum
TÍTULO:

EVALUATION OF JOINING METHODS FOR THERMOPLASTIC COMPOSITE MATERIALS

PALAVRAS-CHAVES:

Keywords: Elium®; Thermoplastic; Welding; Joining materials.

PÁGINAS: 154
GRANDE ÁREA: Engenharias
ÁREA: Engenharia de Materiais e Metalúrgica
SUBÁREA: Materiais Não-Metálicos
ESPECIALIDADE: Materiais Conjugados Não-Metálicos
RESUMO:

This study presents the methodology applied for the manufacturing of composite plates with carbon fiber and Elium®150 resin using the vacuum-assisted resin transfer molding (VARTM) method. Using adhesive bonding and infrared light heating welding at thermoplastic composite materials to obtain samples. The Elium® resin was thermally characterized using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA), and thermomechanical analysis (TMA). Aiming to compare the results with different types of reinforcements, composite plates of Elium® resin matrix and fiberglass and carbon fabric were laminated. DSC analysis of pure resin resulted in peak cure temperature of 82.92ºC, a DSC Tg of 94.16ºC, and an enthalpy of 216.63 J/g. DMA results showed Tg of 50.82ºC for the pure resin, Tg of 71.9ºC for the carbon fiber, and Tg of 98.47ºC fiberglass reinforced polymer. TMA indicated a Tg of 91ºC for carbon fiber and 93ºC for fiberglass. Ultrasonic tests revealed no defects or voids in composite plates of glass or carbon fiber. Based on the thermal characterization results, the process parameters were established as 150, 175 and 200 ºC (heating phase) for temperature and 0.4 or 0.5MPa for pressure at consolidation phase on the welding process. Samples were analyzed by lap shear stress with higher shear stress values (14.6 MPa) observed for the composite samples containing fiberglass reinforcement processed at 150ºC and 0.4 MPa pressure. Fiberglass samples revealed better attachment between fiber and the matrix due to more effective chemical compatibility. In contrast, carbon fiber samples presented significant adhesive failures, with the resin detaching from fiber, indicating insufficient adhesion. This behavior is consistent with the loss of matrix rigidity observed through DMA, particularly at higher welding temperatures. Bonded samples exhibited greater shear strength since they are processed below glass transition temperature determined by DMA technique.

MEMBROS DA BANCA:
Presidente - 1842622 - ANTONIO CARLOS ANCELOTTI JUNIOR
Interna - 1560408 - MARIA ELENA LEYVA GONZALEZ
Externo ao Programa - 3386251 - RICARDO MELLO DI BENEDETTO - UNIFEIExterna à Instituição - CARLA JÚNIA SANTOS
Externa à Instituição - LORENA CRISTINA MIRANDA BARBOSA
Externo à Instituição - LUIZ CLAUDIO PARDINI - ITA