Banca de DEFESA: GERLANEA SILVA DE OLIVEIRA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : GERLANEA SILVA DE OLIVEIRA
DATA : 29/07/2016
HORA: 14:00
LOCAL: Sala de aulas do PPGCEM
TÍTULO:

Estudo e Caracterização dos Sinterizados de Metal Duro com Adição de Ni Através da Moagem de Alta Energia.

PALAVRAS-CHAVES:

carbide, WC-Ni, powder metallurgy, high energy and sintering grinding.

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

Hard metal is a composite material used in various areas of machining, mining and construction and can be applied directly to components of oil and gas drilling equipment. It consists of a ceramic part, carbides of refractory metals that is the hard phase and the ductile phase, which can be cobalt, nickel or iron. The ductile metallic phase is the matrix or the binder phase of the composite, which gives toughness. The properties of the composites, particularly W-Co hard metal, which is the most commonly used, can be easily modified or enhanced for a particular application by variation of these phases, or adding other elements. Nickel has received more attention in the development of scientific research, due to the economic aspects and the mechanical properties, it´s new alternatives to cobalt. In this study, the effects of different amounts of  Ni and sintering parameters (temperatures and time of isothermal) on sintered properties the WC-Ni were studied. The sintered products were obtained through the processing steps of powder metallurgy, in which powders of tungsten carbide - WC with addition of 5 and 15 wt%. Nickel - Ni were milled in a high energy planetary milling for 8 hours. Then, the achieved powders were compacted in a uniaxial press under a load of 300 MPa in a cylindrical die with 5 mm in diameter and height. The sintering of the green samples were carried out at temperatures from 1350 ° C to 1450º C with isotherms of  30 and 90 minutes in a dilatometer device. Other samples were sintered at 1350º C for 30 and 90 minutes isotherms in the vacuum furnace. Starting powders (WC and Ni) and the milled powder were characterized by X – ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS); and sintered samples were also characterized by SEM, EDS, optical microscopy (OM), and microhardness measurements. The result microhardness was added to the amotra WC-5% PNI sintered at 1450 ° C isotherm at 90 minutes in the dilatometer. In the vacuum furnace the best resutado microhardness was for samples (WC-15% p.Ni) sintered at 1350 ° C with 90 minutes isotherm.

MEMBROS DA BANCA:
Presidente - 345842 - UILAME UMBELINO GOMES
Interno - 1350249 - RUBENS MARIBONDO DO NASCIMENTO
Externo à Instituição - ARIADNE DE SOUZA SILVA - UFRN
Externo à Instituição - LEILIANE ALVES DE OLIVEIRA - UFRN