GRAIN GROWTH IN DILUTE TUNGSTEN HEAVY ALLOYS DURING LIQUID-PHASE SINTERING UNDER MICROGRAVITY CONDITIONS
SCIE
SCOPUS
- Title
- GRAIN GROWTH IN DILUTE TUNGSTEN HEAVY ALLOYS DURING LIQUID-PHASE SINTERING UNDER MICROGRAVITY CONDITIONS
- Authors
- Johnson, JL; Campbell, LG; Park, SJ; German, RM
- Date Issued
- 2009-02
- Publisher
- SPRINGER
- Abstract
- Tungsten heavy alloys with compositions ranging from 35 to 93 wt pct tungsten were liquid-phase sintered at 1500 A degrees C under microgravity conditions for isothermal hold times ranging from 1 to 600 minutes. The solid-volume fraction, grain size, grain size distribution, connectivity, and contiguity of the sintered microstructures were quantitatively measured. From these data, grain-growth-rate constants are determined for solid-volume fractions ranging from 0.048 to 0.858 and are compared to the predictions of several grain-coarsening models. The measured grain size distributions are shown to be self-similar and are fit to a Weibull distribution. Three-dimensional (3-D) grain size distributions from several coarsening models are transformed into grain size distributions for two-dimensional (2-D) cross sections, for comparison with the experimental data. Chi-squared tests and G-tests show that a coalescence model for grain growth fits the experimental observations better than solution-reprecipitation models, even for dilute tungsten heavy alloys.
- URI
- https://oasis.postech.ac.kr/handle/2014.oak/11545
- DOI
- 10.1007/s11661-008-9745-5
- ISSN
- 1073-5623
- Article Type
- Article
- Citation
- METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE, vol. 40A, no. 2, page. 426 - 437, 2009-02
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