Banca de QUALIFICAÇÃO: FÁBIO GUSTAVO LIMA PEREIRA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
DISCENTE : FÁBIO GUSTAVO LIMA PEREIRA
DATA : 22/12/2016
HORA: 09:30
LOCAL: Sala de de reunioes PPGCEM
TÍTULO:

Fatigue and fracture of base Ni superalloys, Inconel 625, with ration Stress R = - 1

PALAVRAS-CHAVES:

Fatigue. Failure mechanism. Nickel-based superalloy. S-N curve.

PÁGINAS: 100
GRANDE ÁREA: Engenharias
ÁREA: Engenharia de Materiais e Metalúrgica
RESUMO:

The fatigue process in materials is the failure mechanism with the presence
of cyclic stresses. Surface flaws and stress concentrators may lead to nucleation of
cracks during this process. The cracks propagate and cause component fracture after
a sufficient number of cycles. This failure mechanism has become increasingly
important as soon as the technological progress has enabled the implementation of
a larger number of structures subjected to different modes of loading and vibrations
such as the equipment used in the pre-salt industry. New materials are being developed
especially for this sector and they have to meet some specifications to work
on this harsh environments. Examples of materials used under such circumstances
are the resistant nickel-based alloys. In this context, this study aims to evaluate the
behaviour of the Nickel-based superalloy, Inconel 625, under load with load ratio R
equal to -1 as well as its mechanical and microstructural properties. The mechanical,
microstructural and morphological characterization of Inconel was analyzed
by axial fatigue, tensile, hardness, optical microscopy, SEM and XRD tests. The
results indicated that Inconel 625 is able to associate high mechanical strength and
moderate hardness with good ductility. The diffractometry allowed to verify the
presence of a matrix phase 𝛾 and carbides of the types 𝐶𝑟23𝐶6, MoC e NbC. The
development of the S-N curve made it possible to estimate the fatigue strength of
the material to be approximately 255 MPa. The fracture surfaces were observed by
using scanning electron microscopy, in order to investigate the effects produced by
fatigue cracks. The presence of beach marks and fatigu

MEMBROS DA BANCA:
Externo ao Programa - 2345599 - BISMARCK LUIZ SILVA
Externo à Instituição - JORGE MAGNER LOURENÇO - IFRN
Interno - 1938946 - NICOLAU APOENA CASTRO
Presidente - 1350249 - RUBENS MARIBONDO DO NASCIMENTO