The Effect of Eutectic Microstructures on the Mechanical Properties of Ceramic Oxides.

摘要

Various experimental techniques for the production of unidirectionally solidified oxide eutectics were examined. These included a modified Bridgman-Starkbarger technique and bottom cooling of melts held in platinum crucibles. It was concluded that the best approach,at least for experimental purposes,was the floating molten zone technique and the successful use of a number of variations of this technique was demonstrated. Many different eutectic systems were directionally solidified and the mechanical properties of the Al2O3-ZrO2 (Y2O3), Y2O3-ZrO2, CaZrO3-ZrO2and MgO-CaO systems are described in considerable detail. The strength results indicate that oxide materials prepared in this manner can exhibit exceptional strengths and significant increases in toughness at elevated temperatures. The various reasons and requirements for obtaining exceptional mechanical properties in this class of materials are considered. (Modified author abstract)