Introduction of structural ceramics

Oxide ceramic is a ceramic material with aluminum oxide (Al2O3) as the main body, used in thick film integrated circuits. Alumina ceramics have good conductivity, mechanical strength and high temperature resistance. To toughen alumina ceramics, the current toughening method is adding 20% zirconia (ZrO2) to toughen. When pure Zr02 is added to alumina and the particles form ZrO2 toughened alumina ceramics, when the added content is appropriate, the toughness can be significantly improved. The toughening effect mainly comes from the following mechanisms:

1. Refine the alumina crystal grain matrix.

2. Zirconia phase transformation and toughening.

3. Microcrack toughening.

4. Crack turning and bifurcation. The mechanical properties of commercial high-purity alumina ceramics and ZrO2 toughened alumina ceramics are compared with 99% alumina ceramics. Zirconia toughened alumina ceramics have a density ≥4.1, Rockwell hardness ≥90, Vickers hardness ≥1300, fracture toughness 6.0, flexural strength 480MPa, and compressive strength 3600MPa.