Banca de DEFESA: THIAGO SOUZA VIANA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : THIAGO SOUZA VIANA
DATA : 30/06/2017
HORA: 09:00
LOCAL: Sala de reuniões do DEMat
TÍTULO:

Influence of annealing heat treatments on the microstructure and transformation temperatures of an NiTi alloy.

PALAVRAS-CHAVES:

memory form alloy, nitinol, transformation temperatures, heat treatment.

PÁGINAS: 107
GRANDE ÁREA: Engenharias
ÁREA: Engenharia de Materiais e Metalúrgica
SUBÁREA: Metalurgia de Transformação
ESPECIALIDADE: Tratamentos Térmicos, Mecânicos e Químicos
RESUMO:

In the present work, the influence of heat treatments on the microstructural transformations of an approximately equiatomic NiTi memory form alloy was investigated. A NiTi wire with 2.5 mm in diameter, received in the work hardened state, was submitted to annealing heat treatments at 450°C and 500°C in order to verify the calorimetric and microstructural changes. Optical and electronic microscopy and X-rays diffraction were employed to characterize the structure and the phases morphology. The analysis via differential scanning calorimetry allowed the determination of the transition temperatures (As, Af, Ms, Mf) and the change in the transformation temperatures between the as received worked hardened and annealed material is discussed. The microstructure in the work hardened condition and after the annealing heat treatments was analyzed in detail via field emission scanning electronic microscopy (MEV-FEG), which showed a coarsening of the martensite plates for higher temperatures and longer heat treatment times. Microhardness measurements did not reveal any significant influence of the annealing or subzero heat treatments on the mechanical behavior of the alloy.

MEMBROS DA BANCA:
Presidente - 2156996 - AUGUSTO JOSE DE ALMEIDA BUSCHINELLI
Interno - 1938946 - NICOLAU APOENA CASTRO
Interno - 1350249 - RUBENS MARIBONDO DO NASCIMENTO
Externo à Instituição - WALMAM BENÍCIO DE CASTRO - UFCG