Kemija u Industriji (Dec 2008)
Microstructure Analysis of Thermally Etched Alumina Ceramics
Abstract
Ceramography is the art and science of preparation, examination, and evaluation of ceramic microstructures. Microstructure is the structure level approximately 0.1 to 100 μ m between the wavelength of visible light and the resolution limit of the naked eye. The microstructure includes most grains, secondary phases, grain boundaries, pores, microcracks, hardness microindentations. Investigation and evaluation of ceramic microstructure is very important because a number of mechanical, optical, thermal, electrical and other properties of ceramics are significantly affected by the microstructure. The techniques for ceramographic preparation are divided into five parts: sawing, mounting, grinding, polishing and etching.In this paper a method for preparation of a cold isostatically pressed high purity alumina ceramics (α-Al2O3) is described. Microstructure analysis of prepared ceramics was performed by means of optical microscopy (OM), scanning electron microscopy (SEM) and atomic force microscopy (AFM). Porosity is determined on the polished sample; grain size is measured after thermal etching. The mean grain diameter is determined by means of lineal-intercept method, circular-intercept method and image analysis.
