Novas Tecnologias - NTF 5

Title :

PRODUCTION OF COMPLEX PARTS BY LOW-PRESSURE INJECTION MOLDING OF GRANITE POWDERS. 
Part I - Preparation of feedstock, injection and debinding

Abstract :
During the quarrying of the ornamental stones in Ceará state (Northeastern Brazil), a great amount of waste material is produced. Since most of this powder has not found economic use to date, it is simply, discarded becoming a potential environmental hazard. This paper describes the use of granite powder as feedstock for powder injection moulding, thus replacing costly ceramic materials. Initially the selected powder was milled and sieved. The resultant fines were then characterised by x-ray diffraction and scanning electron microscopy and the particle characteristics were also determined. The characterised material was mixed with a low-viscosity organic vehicle comprised of carnauba wax, low-density polyethylene and stearic acid. Rheology studies were performed in order to determine the optimum powder content compatible with the low-pressure injection moulding process, and the mixture was injected. Small thread-guides were produced using a two-cavities mould manufactured from low-carbon steel. Thermal analysis was employed to determine the appropriate debinding schedule. Investigation of both as-moulded and debound parts showed that the granite powder has a great potential as a substitute for more expensive ceramic materials.
Autores :
Nogueira, Ricardo Emílio F. Q.
Felix, Paulo César G.
Blazdell, Philip Frank
Trabalho Completo :


  1o. Cobef | Comissão Organizadora | Palestras | Sessões Técnicas | Autor | Revisores