(15b) Microstructure Study of a-Alumina Powder Derived from Aluminum Hydroxide

a-alumina is an useful material ,which can be used on high performance ceramic and refractory ,polishing and chemistry industry etc. Now,many higher demands have been put forward on materials with the developing of science and technology, for example, many fields hope ceramic has higher hardness and toughness. Microstructure has important influence on some performance of a-alumina ,such as stuff ratio ,rheological nature, suspending nature etc, which will influence the performance of the final materials. Several influence factors on a-alumina ,such as predecessor, temperature additives, have been studied in this paper using XRD/SEM analytic technique .After sintering, the particle will keep the original shape, but microstructure has great difference because of phase transformation and dehydration. Temperature influence the crystals size mainly, which will grow bigger with sintering temperature heightening .Additives has more influence on the microstructure of a-alumina ,which can change the crystallization habit of a-alumina greatly , so many different microstructure of a-alumina can be made by changing additives.