Nucleation and epitaxial growth of highly textured Al2O3-ZrO2 nanoeutectic rapidly solidified from oxyacetylene flame remelting

作者:Wang, Zhi-Gang; Ouyang, Jia-Hu*; Wang, Yu-Jin; Liu, Zhan-Guo; Ma, Yong-Hui; Xie, Ling-Yun
来源:Ceramics International, 2018, 44(17): 22027-22031.
DOI:10.1016/j.ceramint.2018.08.204

摘要

The nucleation and epitaxial growth behavior of a novel Al2O3-ZrO2 nanoeutectic rapidly solidified from the oxyacetylene flame remelting have been investigated. The nanoeutectic ceramic consists mainly of highly textured cellular structure with an average interphase spacing of 136 nm. Especially, a singular transition mechanism associated with "one-step cellular refining" to "two-step cellular refining" is proposed in a variable region from a coarse irregular to an ultrafine lamellar structure, and the regional undercooling is estimated to be 0.57-2.86 K. The Al2O3 phase nucleates as the leading phase in the rapidly solidified structure according to a quantitative calculation of nucleation rate. The cellular eutectic exhibits with a tilted feature, where its cellular growth deviates from the heat flow direction to a preferred growth orientation.