Banca de QUALIFICAÇÃO: GERLANEA SILVA DE OLIVEIRA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
DISCENTE : GERLANEA SILVA DE OLIVEIRA
DATA : 14/07/2016
HORA: 07:30
LOCAL: A definir
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:

ABSTRACT

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 tenacity. 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 increased attention in the development of scientific research, due to the economic aspects and the mechanical properties, the new alternatives to cobalt. In this study, the effects of variation percent Ni and sintering parameters were studied (sintering temperatures and isotherms) the WC-Ni sintered properties. 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 ground in a high energy planetary mill for 8 hours. Then, the particulate powders were compacted in a uniaxial press under a load of 300 MPa cylindrical die 5 mm in diameter and height. The sintering of the compacted green was carried out at temperatures from 1350 ° C to 1450ºC with isotherms 30 and 90 minutes, dilatometer, and the temperature 1350º C, 30 and 90 minutes isotherms in the vacuum furnace. starting powders (WC and Ni) and the ground were characterized by diffraction X - ray (XRD), scanning electron microscopy (SEM) and energy dispersive (EDS); and sintered samples were characterized by SEM, EDS, optical microscopy (OM), and microhardness measurements. The results of realtiva density were greater for the samples (WC-15% p.Ni) sintered at 1350 ° C with 90 minutes isotherm, the vacuum furnace and dilatometer, with values equal to 93.41% and 97.19% respectively.

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