Fabrication and creep studies on open cell nickle structures |
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Collaborators: N/A
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Materials:
Metals
Application: Structural Technique: Processing Characterization |
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Cellular Ni-base alloy structures have potential for light to medium load bearing applications at elevated temperatures as these structures may be actively cooled by fluid flow. In this study open-cell Ni structures were fabricated using two different processes. A process to create honeycomb cells was developed that relied on diffusion bonding of thin walled tubes in which sintering forces were used to convert circular core geometry into hexagonal cores. Linear celluar structures with low density (~10% dense) were prepared by this method. The other process utilized woven wire mat to diffusion bond a layered stack to create a denser structure (56% denser). Room temperature deformation behavior of these structures and the compressive creep behavior of the honeycombs was characterized and the results compared with those of a solid material. FE analysis of creep deformation of ideal honeycombs was carried out to provide more insight into the nature of creep in such materials. It is shown that geometry of the honeycomb plays an important role in determining the creep response related to geometric 'weakening' and 'hardening' processes in the cellular structure. |