Description of the zirconia and alumina ceramic
Zirconia ceramics, ZrO2 ceramics, have the excellent properties of melting point and boiling point, high hardness, thermal insulation, and high temperature.
Pure ZrO2 is white, with impurities yellow or gray, generally containing HfO2, not easy to be separated. The world's proven zirconium resources are about 19 million tons, and zirconia is usually purified by zirconium ore. Under normal pressure, pure ZrO2 has three crystalline states: single oblique oxidation zirconium, sifang zirconia, and cubic zirconia. The three types of crystals exist in different temperature ranges and can be converted to each other:
The relationship between temperature and density
(1) monoclinic zirconia temperature < 950 ℃, the density of 5.65 g/cc.
(2) the quartet zirconia temperature 1200-2370 ℃, the density of 6.10 g/cc
(3) cubic zirconia temperature > 2370 ℃, the density of 6.27 g/cc
Since zirconia ceramics have high toughness, high bending strength and high wear resistance, excellent thermal insulation performance, thermal expansion coefficient is close to the advantages of steel, so it is widely used in the field of structural ceramics. Mainly include: Y - TZP grinding balls, dispersing and grinding media and nozzle, ball valve tee, zirconia molds, mini fan axis, fiber-optic pin, optical fiber sleeve, wire drawing die and cutting tool cutting tools, wear-resisting, clothing buttons, watch case and strap, bracelet and pendant, ball bearing, golf light shot rod and other room temperature wear-resisting zero devices, etc.
2. Introduction and application of alumina ceramic
1, the introduction of alumina ceramic
Alumina ceramics is a ceramic material with alumina (Al2O3) as the main body and used in thick film integrated circuit. Alumina ceramics has good conductivity, mechanical strength and high temperature resistance. It should be noted that ultrasonic is needed for washing. Alumina ceramics is a kind of widely used ceramic, because of its superior performance, the application of modern society has become more and more extensive, to meet the needs of daily use and special performance.