| 1. |
- Federzoni, L., et al.
(författare)
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Comparison of computer models representing powder compaction process: State of the art review
- 1999
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Ingår i: Powder Metallurgy. - : Informa UK Limited. - 0032-5899 .- 1743-2901. ; 42:4, s. 301-311
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents a benchmark study on the use of simulation models to represent the powder compaction process. A two level part that represents a synchroniser hub is used as detailed experimental information for this part is documented in the literature. The models used incorporate different representations of friction and material yielding behaviour together with different fill densities. The study shows that computer modelling is capable of predicting density distributions and tool set force levels for the powder compaction process. It has highlighted the sensitivity of the output with respect to friction, fill density, and material yield models. It has also shown that models that incorporate material behaviour using different material models yield surprisingly reasonable results. Based on best performance, it is now possible to predict density to within 0·05 g cm-3 and tool set force within 10%for an iron powder. The computational requirements indicate a simulation time of typically 1 h for a two level component. This makes simulation a practical tool for this industry sector.
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| 2. |
- Häggblad, Hans-Åke, et al.
(författare)
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A micro mechanical based constitutive model for finite element simulation of hot isostatic pressing of powder
- 1995
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Ingår i: Computer Methods in Applied Mechanics and Engineering. - : Elsevier BV. - 0045-7825 .- 1879-2138. ; 128:1-2, s. 191-198
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Tidskriftsartikel (refereegranskat)abstract
- Hot isostatic pressing (HIP) facilitates new designs and product shaping, for example by direct manufacture of composite products with differing materials in the various parts (compound). The specific material characteristics are thus created at the manufacturing stage (consolidation), and these in themselves often give good possibilities regarding shape, so-called NS (Net Shape)-or NNS (Near Net Shape)-manufacture. The HIP-technique is used economically in the low series production of complex-shaped steel parts. In order to achieve quality products, an integration of material, design and manufacturing technology is necessary, since the function and cost of the final component depends to a large extent on the development of production technology and its integration with design technology. Simulation of the hot isostatic pressing process is required to reduce the need for expensive and time-consuming experimental design. The use of finite element techniques in analyses of the highly non-linear process is preferable, especially for complex-shaped components. In this work, a micro-mechanical based continuum mechanics model for finite element analysis is presented. The model is used in the finite element simulation of hot isostatic pressing of two components. The results from the analyses correspond well with the experimental results.
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| 3. |
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| 4. |
- Häggblad, Hans-åke, et al.
(författare)
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An International research programme on the mechanics of metal powder forming
- 1996
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Ingår i: Advances in powder metallurgy & particulate materials - 1996. - Princeton, NJ : Metal powder industries federation. - 1878954598 ; , s. 179-192
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Konferensbidrag (refereegranskat)abstract
- A collaborative research programme, Mechanics of Metal Powder Forming, has been initiated at PM'94 Conference in Paris. It aims at evaluating the procedures and facilities involved in the numerical modelling of the forming of metal powders by hot and cold compaction, in particular through the identification of bench mark problems. This paper gives a general presentation of this programme and focus on the advancement of cold compaction programme. Material investigated was Distaloy AE (Fe-4Ni-1.5Cu-0.5Mo).
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| 5. |
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| 6. |
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| 7. |
- Li, W.B., et al.
(författare)
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Constitutive laws for hot isostatic pressing of powder compact
- 1997
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Ingår i: Powder Metallurgy. - : Informa UK Limited. - 0032-5899 .- 1743-2901. ; 40:4, s. 279-281
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Tidskriftsartikel (refereegranskat)abstract
- The present state of hipping modelling is briefly reviewed using the principles of densification theory and plastic deformation theory for porous materials on the basis of a macro- and microscopic approach. The features of these two approaches are discussed. The constitutive equation for a porous compact relating the strains and stresses (macroscopic approach) is modified by incorporating the rate equations for densification mechanisms (microscopic approach). A new modified constitutive equation is then derived which combines the advantages of both approaches. Based on this equation, the hipping process can be simulated. The density and shape change of a porous compact during densification or deformation processes under conditions of either isostatic or nonisostatic pressure can be predicted
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| 8. |
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| 9. |
- Lindgren, Lars-Erik, et al.
(författare)
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Automatic remeshing for three-dimensional finite element simulation of welding
- 1997
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Ingår i: Computer Methods in Applied Mechanics and Engineering. - 0045-7825 .- 1879-2138. ; 147:3-4, s. 401-409
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Tidskriftsartikel (refereegranskat)abstract
- Three-dimensional finite element simulation of electron beam welding of a large copper canister has been performed. The use of an automatic remeshing algorithm, based on a graded hexahedral element was found to be effective. With this algorithm the strongly nonlinear thermomechanical effects locally close to the moving heat source can accurately be modelled using a dense element mesh that follows the heat source.
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| 10. |
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