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Synthesis , structure and mechanical properties of ice-templated tungsten foams
| Content Provider | Semantic Scholar |
|---|---|
| Author | Röthlisberger, André Häberli, Sandra |
| Copyright Year | 2016 |
| Abstract | Tungsten foams with directional, controlled porosity were created by directional freeze-casting of aqueous WO3 powder slurries, subsequent freeze-drying by ice sublimation, followed by reduction and sintering under flowing hydrogen gas to form metallic tungsten. Addition of 0.51 wt% NiO to the WO3 slurry improved the densification of tungsten cell walls significantly at sintering temperatures above 1250 °C, yielding densely sintered W–0.5 wt% Ni walls with a small fraction of closed porosity (,5%). Slurries with powder volume fractions of 15–35 vol% were solidified and upon reduction and sintering the open porosity ranges from 27–66% following a linear relation with slurry solid volume fraction. By varying casting temperature and powder volume fraction, the wall thickness of the tungsten foams was controlled in the range of 10–50 lm. Uniaxial compressive testing at 25 and 400 °C, below and above the brittle-to-ductile-transition temperature of W, yields compressive strength values of 70–96 MPa (25 °C) and 92–130 MPa (400 °C). |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://www.dunand.northwestern.edu/pdf/rothlisberger2016.pdf |
| Language | English |
| Access Restriction | Open |
| Subject Keyword | 3-Mercaptopropionic Acid Cell Wall Compressive Strength Dye-sublimation printer Flow Foam drug form Freeze Drying Hydrogen Percent Volume per Volume Slurry Sublimation - mental defence mechanism Thickness (graph theory) Volume fraction Walls of a building nickel tungsten |
| Content Type | Text |
| Resource Type | Article |
