Effect of gravity on three-dimensional coordination number distribution in liquid phase sintered microstructures

Journal Article · Fri Oct 08 04:00:00 EDT 1999 · Acta Materialia

DOI:https://doi.org/10.1016/S1359-6454(99)00164-0· OSTI ID:20000506

Tewari, A; Gokhale, A M; Gereman, R M

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, Journal Name: Acta Materialia Journal Issue: 13 Vol. 47; ISSN 1359-6454; ISSN ACMAFD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
COORDINATION NUMBER
CORRELATIONS
GRAVITATIONAL FIELDS
IMAGE PROCESSING
LIQUID METALS
MICROSTRUCTURE
SINTERING
TUNGSTEN ALLOYS