Changes in Microstructures and Properties of Al2O3/ZrO2 (Y2O3) with Different Content of ZrO2

摘要

Based on preparation of Al2O3/ZrO2 (4Y) by combustion synthesis in high-gravity field,the microstructure transformation and properties of the materials are investigated through adjusting the ZrO2 (4Y) content in the composites.As the content ofZrO2 changed from 37％ to 40％,the microstructures of the ceramics transformed the sphere-like tetragonal ZrO2 crystals from the rod-shaped colonies with nanocrystalline structures.Al2O3/33％ZrO2 (4Y) had the maximum relative density,hardness and flexural strength due to the low solidification temperature,the highest volume fraction of the colonies,small-size defect and high fracture toughness,whereas Al2O3/44％ZrO2 (4Y) was somewhat weakened in strength in despite of its highest fracture toughness.