The effect of the microstructure on mechanical properties of directionally solidified Al2O3/ZrO2(Y2O3) eutectic Original Research Article

The eutectic architecture of a continuous reinforcing phase within a higher volume fraction phase or matrix, can be described as a naturally occurring in-situ composite. Here we report the results of experiments aimed at identifying the sources of high temperature creep resistance and high levels of strength in a two phase Al2O3/ZrO2(Y2O3) system. The mechanical properties of two phase Al2O3/ZrO2(Y2O3) eutectic are superior to that of either constituent alone due to strong constraining effects provided by the coherent interfaces and micrsostructure. The Al2O3/ZrO2(Y2O3) eutectic maintains a low energy interface resulting from directional solidification and can produce strong and stable reinforcing phase/matrix bonding. The phases comprising a eutectic are thermodynamically compatible at higher homologous temperatures than man-made composites and as such offer the potential for superior high temperature properties.