Alumina/yttrium aluminum garnet (YAG) eutectic rods of 1 mm in diameter were grown by the laser‐heated floating zone method at different rates to obtain microstructures with the same morphology but of very different domain size. The mechanical properties of the rods (hardness, toughness, strength) were measured at ambient temperature in the longitudinal and transverse directions and, in addition, the longitudinal flexure strength was determined up to 1900 K. The fracture resistance and the hardness of the eutectics at ambient temperature were isotropic and independent of the domain size. On the contrary, the longitudinal strength was significantly higher than the transverse one and increased linearly with the growth rate, reaching almost 2 GPa in the rods grown at 750 mm/h, which presented a submicrometer homogeneous microstructure. The critical defect size was equivalent to that of Al2O3 and YAG domains in the microstructure, and the strength was proportional to the inverse of the square root of the domain size. In addition, the strength retention of the eutectics was remarkable, and the rods with the finest microstructure withstood 1.53 GPa at 1900 K. The moderate reduction in strength at very high temperature was induced by the homogeneous coarsening of the microstructure.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.