Banca de DEFESA: ELLA RAQUEL DO VALE SOUZA
Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.DISCENTE : ELLA RAQUEL DO VALE SOUZA
DATA : 04/09/2018
HORA: 08:00
LOCAL: Sala de aula PPGCEM
TÍTULO:
Sintering Ni/SiC composites from NiO
PALAVRAS-CHAVES:
Ni composites, NiO, SiC, powder metallurgy
PÁGINAS: 96
GRANDE ÁREA: Engenharias
ÁREA: Engenharia de Materiais e Metalúrgica
RESUMO:
Metal matrix composites reinforced by carbide particles are promising engineering materials as a result of a combination of mechanical, corrosion and wear resistance at high service temperatures. However, the toxicity of Ni impairs the use of its powder. Alternatively, NiO can be used as starting material and be reduced during processing of the composite. The present study aimed at the production of Ni-SiC composites from NiO-SiC mixtures. The effect of the pressing load on the dilatometric behavior of the mixtures was investigated. NiO powders with average particle size 14 µm were mixed (0, 3, 10 and 20 wt.%) with SiC of average particle size 14.75 µm and attrition-milled during 1 h. The mixtures were then granulated using 1.5 wt.% paraffin in hexane solution and uniaxially pressed under 200 MPa or 400 MPa. The cylindrical pellets were then sintered in a dilatometer at heating rates of 5 ºC or 10 ºC/min. The density of the sintered samples was evaluated according to the combination of pressing load and dilatometric profile. The results revealed that homogenous NiO-SiC mixtures could be produced. Pellets pressed under 400 MPA depicted higher density. Sintering at 5 /C/min heating rate resulted in improved densification. The addition of 10 wt. % of SiC in the Ni matrix allowed the hardening with greater microstructural homogeneity and better continuity of the matrix, presented higher hardness and surface dense value, proved by SEM images.
MEMBROS DA BANCA:
Presidente - 1298936 - ANTONIO EDUARDO MARTINELLI
Externo à Instituição - MARIA ROSEANE DE PONTES FERNANDES - UFPB
Externo ao Programa - 1652765 - MAURÍCIO MHIRDAUI PERES