Banca de QUALIFICAÇÃO: SAMARA MELO VALCACER

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
DISCENTE : SAMARA MELO VALCACER
DATA : 03/03/2017
HORA: 13:30
LOCAL: Sala de aula do PPGCEM
TÍTULO:

Study and characterization of the effect of the addition of 5%, 10% and 15% of alumina in the WC-3% Ni composite processed through powder metallurgy

PALAVRAS-CHAVES:

Composite

PÁGINAS: 102
GRANDE ÁREA: Engenharias
ÁREA: Engenharia de Materiais e Metalúrgica
SUBÁREA: Metalurgia de Transformação
ESPECIALIDADE: Metalurgia de Pó
RESUMO:

The composite materials appeared to meet a market demand, which indicated the need for materials with agglutinated properties. A composite well known for its properties is the tungsten carbide with cobalt as a binder (WC-Co). It is known that the mentioned hard metal has high hardness indicated for use in cutting tools, however, when it is tried to increase its performance in work, that is, to increase the speed of cut the studies indicate that Cobalto oxidates, thus generating the Breaking of the composite. Attention to the aforementioned, we are currently studying the WC-Ni composites, which show a marked hardness loss. This study proposes a new composite material that presents high hardness, does not degrade even at high temperatures (low corrosion), good toughness and even a reduction of weight when compared to WC-Co. The composite in question is a mixture of tungsten carbide, alumina and nickel. The study aims to establish characteristics of the composite WC-3% Ni when added with 5, 10 and 15% w Al2O3. The process of obtaining it was via powder metallurgy. High-energy milling (400 rpm), uniaxial compaction at 400Mpa and vacuum sintering were carried out at temperatures of 1450 and 1550 ° C with sintering stage of 1h. The samples were characterized by: laser particulometry, XRD, MEV, hardness and also the densification of the samples was measured. The results were promising since sintering in all its stages in all the compositions, attention is drawn to the composition with addition of 15% of alumina, which presented high relative density (above 75%) for the two Temperatures studied.

MEMBROS DA BANCA:
Presidente - 345842 - UILAME UMBELINO GOMES
Externo ao Programa - 2613355 - FRANCINE ALVES DA COSTA
Externo à Instituição - ARIADNE DE SOUZA SILVA - UFRN
Externo à Instituição - LEILIANE ALVES DE OLIVEIRA - UFRN
Externo à Instituição - TERCIO GRACIANO MACHADO - IFBA