| Autor: |
Singh, Chandan, Prywer, Jolanta, Yadav, Devinder |
| Předmět: |
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| Zdroj: |
Journal of Materials Engineering & Performance; Oct2023, Vol. 32 Issue 20, p9396-9404, 9p |
| Abstrakt: |
Al-TiB2in situ composites are important class of structural materials where the TiB2 particles are grown in situ within the aluminum matrix. The true morphology of the in situ grown TiB2 particles is not clear as particles with different morphologies are reported in the literature. The present work reports the three-dimensional morphologies and habits of in situ grown TiB2 particles in aluminum-based composites by the halide slat method. TiB2 particles were grown in molten aluminum by the reaction of two fluoride salts; K2TiF6 and KBF4. The TiB2 particles exhibited truncated hexagonal pyramid morphology. It was found that the pyramidal planes are morphologically more important and the crystal is bounded by the fast-growing faces. The habit (predominant facet plane) and growth morphology of the crystals was analyzed through the kinetic-geometric model. The ratio of the relative growth rates of different forms was calculated. The pyramidal form can increase its size by growing faster than the adjacent faces, whereas the basal and prism forms decrease in size if they grow faster than the adjacent faces. We show that depending on the interfacial angle geometry, a given face may or may not enlarge, and the face needs not always constrain the crystal with the slowest growth rate. Both the theoretical analysis and the experiments demonstrate the particles to have hexagonal pyramidal morphology. Finally, the present work explains how past observations suggesting the TiB2 particles to have hexagonal, elongated hexagonal, rectangular, and cubic habits are due to the two-dimensional sections of the truncated hexagonal pyramid. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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