Banca de QUALIFICAÇÃO: MARIANA CHIANCA LÚCIO DA SILVA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
DISCENTE : MARIANA CHIANCA LÚCIO DA SILVA
DATA : 25/01/2017
HORA: 13:30
LOCAL: Sala de Aula PPGCEM
TÍTULO:

STUDY OF WC-Al₂O₃ CERAMIC COMPOSITE VIA POWDER METALLURGY

PALAVRAS-CHAVES:

Composite, Tungsten Carbide, Aluminia, High Energy Milling, Sintering.

PÁGINAS: 67
GRANDE ÁREA: Engenharias
ÁREA: Engenharia de Materiais e Metalúrgica
RESUMO:

Tungsten Carbide (WC) is best known for its excellent physical and mechanical

properties. However, it has limitations, mainly when the tougher and lighter material is requested. An alternative to minimize these problems is a composite WC and alumina (Al₂O₃) composite to reducing density and promoting toughness. Thus, In this work, the effects of powder metallurgy processing parameters on microstructure of particles and sintered composite (WC-Al₂O₃) were studied and mechanical properties of composite for specific application, particularly the microhardness, were analyzed. The composite powders have the following compositions: WC with 5, 10 and 15wt% of Al₂O₃ processed by high energy milling in a planetary milling for 1, 4 and 10 hours. Compacting was done using a uniaxial press in a cylindrical die of 5 mm in diameter under a pressure of 400 MPa. Solid phase sintering was performed in a resistance furnace at 1450 and 1550 °C with 1 hour of holding time and heating rate of 10°C/min in argon atmosphere. The raw materials were characterized by particulometry, X-ray diffraction (XRD), X-ray fluorescence (XRF), B.E.T Method and scanning electron microscopy (SEM). The milled powders and sintered samples were subjected to the same tests and microhardness test was also done for sintered samples as well. The results showed that high energy milling met the targets for particle size and dispersion of composite components. However, due to poor sintering, the microhardness did not achieve to significant results and microstructures with high porosity were observed.

MEMBROS DA BANCA:
Externo à Instituição - ARIADNE DE SOUZA SILVA - UFRN
Externo à Instituição - LEILIANE ALVES DE OLIVEIRA - UFRN
Presidente - 345842 - UILAME UMBELINO GOMES