Effect of gravity on three-dimensional coordination number distribution in liquid phase sintered microstructures
Gravity affects microstructural evolution when a liquid phase is present during sintering. The effect of gravity on the three-dimensional coordination number distribution of tungsten grains in liquid phase sintered heavy alloy specimens is quantitatively characterized. A combination of montage serial sectioning, digital image processing, and unbiased stereological sampling procedures is used to estimate the coordination number distribution in three-dimensional microstructures. The microgravity environment decreases the mean coordination number. However, hardly any isolated grains are observed in the specimens, liquid phase sintered in a microgravity environment. The effect of microgravity on the coordination numbers mainly resides in its effect on the mean coordination number. In all specimens, there is a strong correlation between grain size and coordination number, which can be expressed as [D{sub c}/{bar D}]{sup 2} = C/C{sub 0} where C{sub 0} is the mean coordination number, {bar D} the global average size of the tungsten grains, and D{sub c} the average size of only those grains which have coordination number C.
- Research Organization:
- Georgia Inst. of Tech., Atlanta, GA (US)
- OSTI ID:
- 20000506
- Journal Information:
- Acta Materialia, Vol. 47, Issue 13; Other Information: PBD: 8 Oct 1999; ISSN 1359-6454
- Country of Publication:
- United States
- Language:
- English
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