Title:
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Influence of composition, grain size and iron oxide particles on the strength of consolidated ball-milled iron
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Author:
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Benito Páramo, José Antonio; Casas Quesada, Casimir; Cabrera Marrero, José M.
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Other authors:
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Universitat Politècnica de Catalunya. Departament de Ciència dels Materials i Enginyeria Metal·lúrgica; Universitat Politècnica de Catalunya. PROCOMAME - Processos de Conformació de Materials Metàl·lics |
Abstract:
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In this paper iron powders with two oxygen content (0.2 and 0.6% wt.) have been mechanically
milled and consolidated by hot static pressing at different temperatures to obtain different grain
sizes. At lower temperatures the grain size was in the nanostructured and ultrafine range and
with increasing temperature abnormal grain growth was observed for both compositions. This
led to the development of bimodal grain size distributions. In the samples with lower oxygen
content the grain size and the percentage of coarse grain areas were larger than in the case of
high oxygen content.
The strength and ductility have been determined by tensile tests. For low oxygen content, the
presence of large coarse grains allowed plastic strain in some cases, and for the samples
consolidated at higher temperatures, yield strength of 865 MPa with a 8% total strain were
obtained. For the samples with high oxygen content plastic deformation was no possible in any
case.
The observed stress for both compositions was analysed by two approaches, one based
exclusively in grain boundary strengthening and the other one based in two effects acting at the
same time: grain boundary and particle strengthening. Whereas grain boundary strengthening
seems to fit with the strength of the samples in the nanostructured range, when coarse ferrite
grains appear the addition of particle strengthening help to get better results. This indicates that
the presence of oxides dissolved inside the large grains reinforce the structure of ball-milled
iron. |
Subject(s):
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-Àrees temàtiques de la UPC::Enginyeria dels materials -Nanostructured materials -Deformations (Mechanics) -Plasticitat -Deformació (Mecànica) |
Rights:
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Attribution-NonCommercial-NoDerivs 3.0 Spain
http://creativecommons.org/licenses/by-nc-nd/3.0/es/ |
Document type:
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Article - Published version Conference Object |
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