DIN EN 623-5-2009 先进技术陶瓷.单片陶瓷.一般和结构特性.第5部分:利用显微图像评估法测定相体积分数,德文版本EN 623-5:2009
Advanced technical ceramics - Monolithic ceramics - General and textural properties - Part 5: Determination of phase volume fraction by evaluation of micrographs; English version of DIN EN 623-5:2009-10
This par of EN 623 specifies a manual method of making measurements for the determination of volume fraction of
major phases in advanced technical ceramics using micrographs of polished and etched sections, overlaying a square grid of lines and counting the number of intersections lying over each phase,
NOTE 1 This method assumes that the true phase volume fractions are equivalent to area fractions on a randomly cut cross-section according to stereological principles,
NOTE 2 Guidelines for polishing and etching of advanced technical ceramics can be found in Annexes A and B,
The method applies to ceramics with one or more distinct secondary phases, such as found in Al203/ZrO2, Si/SiC,or Al203SiCw.
If the test material contains discrete pores, these can be treated as a secondary phase for the purpose of this method provided that there is no evidence of grain pluck-out during polishing being confused with genuine pores.
NOTE 3 If the material contains more than about 20 % porosity there is a strong risk that the microstructure will be damaged during the polishing process, and measurement of volume fraction of pores may become misleading.
Secondary phase volume fractions or porosity present at levels of less than 005 are subject to considerable error and potential scatter in results, A larger number of micrographs than the minimum of three is normally needed to improve vthe consistency and accuracy of the results,
NOTE 4 Many ceramics contain small amounts of secondary glassy phases. In order to make a reasonable estimate of
glassy phase content, the glass material between crystalline grains should be readily observable, and thus should be at least 0,5μm in width, The method in this European Standard is not considered appropriate for narrow glassy films around grains
This method assumes that the selected regions of a prepared cross-section are statistically representative of the whole sampled section,
NOTE 5 Microstructures are seldom homogeneous, and the phase contents can vary from micrograph to micrograph. It is essential to survey a sufficiently wide area of the prepared section to ensure that those areas selected for evaluation are representative and do not contain eye-catching irregularities, Some users of this European Standard can wish to apply automatic or semiautomatic image analysis to micrographs or directly captured microstructural images, This is currently outside the scope of this European Standard but some guidelines are given in Annex C.