High-temperature alumina powder is made of industrial aluminum hydroxide and bauxite, molecular sieve and grinding balls as raw materials, and is calcined in a tunnel kiln for a long time at high temperature. What effect will the excessive iron oxide content in the high-temperature alumina powder have on ceramic What?
The most intuitive effect of high iron oxide in alumina powder is the color of the ceramic, so how does it affect its color?
For the content of iron oxide in the high-temperature alumina powder, on the one hand it refers to the chemical Fe incorporated therein, and on the other hand it refers to the fine free iron contained in the powder (also known as mechanical iron). For the chemical Fe, it usually exists as Fe2O3. For the Fe particles entrained by A12O3 in the raw material during the ceramic sintering process, red or black spots appear on the inside or surface of the ceramic, which not only affects the appearance of the ceramic substrate, but also affects its insulation performance, so once. The occurrence of spots will cause the product to be scrapped and reduce the yield. At the same time, Fe2O3, if the content is too high, will also cause the color of the ceramic substrate to turn yellow. The reason is closely related to the color reaction of Fe ions instead of Al ions in the corundum character.
