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Physical characterisation of particles and rheological of a heterogeneous system used in low-pressure injection moulding; Caracterizacao fisica de particulas e reologica de um sistema heterogeneo utilizado em moldagem de pos por injecao a baixa pressao

Abstract

The powder injection moulding process is a recent technology, which offers as advantages a high production of complex geometry metal parts, with low cost, where secondary operations of machinery are unnecessary. The main of this thesis was centered on a coarse powders feedstock injection. The process begins with the composition of the mass, that is the combination of metal powders with organic binders. The following steps succeed injection in moulds, debinding, sintering and, if necessary, cleaning. For the formulation of the feedstock it is indispensable the characterisation of the powders. This is little mentioned in the open literature and brings up controversy among authors. At first, a series of powders characterisations of AISI 316 L stainless steel (below 25 {mu}m) was adopted. The next step was to characterise the rheological behaviour of the feedstock using different rheological apparatus, so as to find the most appropriate equipment to the low-pressure powder injection molding process. The mass has to present a favourable rheological behaviour, which is low viscosity. The results of the physical characterisation were correlated among themselves and with the rheological characterisation. This was undertaken with the purpose of finding agreement among their values. Finally, the possibility of injection of water  More>>
Publication Date:
Jul 01, 2002
Product Type:
Thesis/Dissertation
Report Number:
INIS-BR-4141
Resource Relation:
Other Information: TH: Tese (Ph.D.); refs., figs., tabs
Subject:
36 MATERIALS SCIENCE; CHEMICAL ANALYSIS; DIFFERENTIAL THERMAL ANALYSIS; EXPERIMENTAL DATA; HARDNESS; MOLDING; PARTICLE SIZE; POLYETHYLENES; POROSITY; POWDER METALLURGY; POWDERS; RHEOLOGY; SCANNING ELECTRON MICROSCOPY; SINTERING; STAINLESS STEEL-316L; THERMAL GRAVIMETRIC ANALYSIS; WAXES
OSTI ID:
20902536
Research Organizations:
Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)
Country of Origin:
Brazil
Language:
Portuguese
Other Identifying Numbers:
TRN: BR0746392065075
Availability:
Available from INIS in electronic form; Also available from the Library of the Brazilian Nuclear and Energy Research Institute (CNEN/IPEN-SP), Sao Paulo, SP
Submitting Site:
BRN
Size:
137 pages
Announcement Date:
Aug 28, 2007

Citation Formats

Zampieron, Joao Vicente. Physical characterisation of particles and rheological of a heterogeneous system used in low-pressure injection moulding; Caracterizacao fisica de particulas e reologica de um sistema heterogeneo utilizado em moldagem de pos por injecao a baixa pressao. Brazil: N. p., 2002. Web.
Zampieron, Joao Vicente. Physical characterisation of particles and rheological of a heterogeneous system used in low-pressure injection moulding; Caracterizacao fisica de particulas e reologica de um sistema heterogeneo utilizado em moldagem de pos por injecao a baixa pressao. Brazil.
Zampieron, Joao Vicente. 2002. "Physical characterisation of particles and rheological of a heterogeneous system used in low-pressure injection moulding; Caracterizacao fisica de particulas e reologica de um sistema heterogeneo utilizado em moldagem de pos por injecao a baixa pressao." Brazil.
@misc{etde_20902536,
title = {Physical characterisation of particles and rheological of a heterogeneous system used in low-pressure injection moulding; Caracterizacao fisica de particulas e reologica de um sistema heterogeneo utilizado em moldagem de pos por injecao a baixa pressao}
author = {Zampieron, Joao Vicente}
abstractNote = {The powder injection moulding process is a recent technology, which offers as advantages a high production of complex geometry metal parts, with low cost, where secondary operations of machinery are unnecessary. The main of this thesis was centered on a coarse powders feedstock injection. The process begins with the composition of the mass, that is the combination of metal powders with organic binders. The following steps succeed injection in moulds, debinding, sintering and, if necessary, cleaning. For the formulation of the feedstock it is indispensable the characterisation of the powders. This is little mentioned in the open literature and brings up controversy among authors. At first, a series of powders characterisations of AISI 316 L stainless steel (below 25 {mu}m) was adopted. The next step was to characterise the rheological behaviour of the feedstock using different rheological apparatus, so as to find the most appropriate equipment to the low-pressure powder injection molding process. The mass has to present a favourable rheological behaviour, which is low viscosity. The results of the physical characterisation were correlated among themselves and with the rheological characterisation. This was undertaken with the purpose of finding agreement among their values. Finally, the possibility of injection of water and gas atomised stainless steel coarse powders feedstock was studied. This presents as main advantage, the reduction of costs for the process. According to the literature, only powders with size below 25 {mu}m are possible to be injected. Hence, starting from the physical characterisation of particles and rheological characterisation of the feedstock, the formulation of an appropriate mass was found for the coarse powders. These coarse powders were characterised by particles below 45 {mu}m. In this case it was necessary to alter drastically the feedstock composition, using high amounts of wax, which lead to unstable rheological conditions. But, it was verified that feedstock constituted of coarse metallic powders which were gas atomised, are injectable, although, these powders resulted in samples with a high porosity level, while, coarse water atomised powders did not present work conditions, being therefore, discarded. (author)}
place = {Brazil}
year = {2002}
month = {Jul}
}