High Al2O3 and Al2O3-ZrO2 ceramics have been successfully applied to armored materials in individuals and combat vehicles. High Al2O3 porcelain as a bulletproof, protective structural material is a novel application. American ceramic armor was first developed in the 1960s as a bullet-proof vest and a base for helicopters.
Its main requirements are to prevent the penetration of bullets, shells and the light weight of the ceramicitites themselves (as opposed to metals).
At present, the world continues to develop, Al2O3 bulletproof ceramics, which are mainly used in combat personnel and combat vehicles, aircraft and helicopters, key parts of the mine explosion and other protection.
Microstructure Armoured Al2O3 ceramics are based on Al2O3-SiO2-CaO-MgO and Al2O3-MgO systems and are 96,97,98,98. In ZrO2 ceramics, Al2O3 and ZrO2 have special ratios (Y2O3 as stabilizers).
Al2O3, as the main raw material, is made with industrialised ultrafine powders, which have a high purity (Al2O3-99 depends on the level of Al2O3, and the content of alpha-Al2O3 should be 95% Wt or higher). The D50 and average grains of Al2O3 powders are 0.35 to 01 to 1. 4 m. BET is 8 to 11m2/g and 2 to 3m2/g respectively. The D50 and average grain size of Y2O3 are 8 to 9m2/g.
Al2O3 and ZrO2 powders choose the right proportion and particle size distribution, the best manufacturing capacity, the best liquid phase sintering and dense.
The significance of microstructure for the application of bulletproof ceramics For the Al2O3 ceramics studied (96,97,98,98. 5, Wt%) phase composition and microstructure is similar, the main crystal phase is corundum, with the increase of Al2O3 content, corundum content also increased accordingly. These ceramics contain a small amount of calcium longstone, as an impurity in the corundum crystal boundary also contains trace spinex. The final ceramic granularity depends on the granularity and distribution of the original Al2O3 powder, because the Al2O3 powder has a smaller size, therefore, the sintered ceramic has a fine microstructure, 2 to 4 m and 1 to 3 m, ZrO2-Al2O3 ceramic based on the best proportion and partial stabilization technology, in order to make ceramics have high performance. The ceramic does not contain a glass phase, the ZrO2 grain of 1 m is evenly distributed between 1 to 2 m of corundum crystals, it is likely that the ZrO2 phase at sintering prevents the growth of corundum crystals, forming a good microstructure.