Enhanced nucleation undercooling and surface self-nanocrystallization of Al2O3-ZrO2(Y2O3) eutectic ceramics

摘要

This present work explores initially the feasibility of producing in-situ surface nanoeutectic Al2O3-ZrO2(Y2O3) (SNAZ) ceramics via the oxyacetylene flame remelting (OAFR) process. Singular cellular nanoeutectics consist of nanoscale lamellae, which prevail in the samples formed under different irradiation times. Ultrafine nanoeutectics are achieved by prolonging the irradiation time, and their formation mechanisms associated with eutectic refinement are proposed to obtain a better understanding on the melt thermal history and microstructural inheritance. The enhanced nucleation undercooling is the essential mechanism associated with the microstructural refinement. SNAZ formed by the OAFR-based rapid solidification seem to offer an inexpensive route to realize in-situ microstructure tailoring or surface shaping.