The techniques being discussed are scanning electron microscope/microscopy and t

Question

The techniques being discussed are scanning electron microscope/microscopy and transmission electron microscope/microscopy.

It is well-known that porosity influences elastic properties and strength. In the case of ceramic materials, the influence of porosity (P) on elastic modulus can be calculated by the following equation: E-Eo(1-1.9P 0.9P2) Imagine that after performing some flexural tests on a ceramic sample you realized that the elastic modulus displayed a much lower value than expected. Therefore, you decided to investigate the volume fraction porosity. Which technique could you use to verify the presence of pores and their size? How would the experiment be performed? Explain in detail.

Explanation / Answer

Scanning electron microscope & transmission electron microscope techniques used to verify the presence of pores and their size.

For the experimental density measurement we can use dimensional method M/V and archimedes method. Both methods are used for ceramics sample for the crystal structure. The difference between thereotical and experimental density is termed as porosity. There are many types of porosity so many methods are available to calculate them.

Depending on the method used to synthesize them, many powders may consist of agglomerates of primary particles which are highly porous. For pores that are acessible (i.e., pores that are not completely isolated from the external surface) , two methods have been used: gas adsorption ( sometimes refered to as capillary condensation) and mercury intrusion porosimetry ( referred to simply as mercury porosimetry ). The characteristics pore feature of interest is the size, taken as the diameter, radius, or width. Therefore, gas condensation is applicable to pore size measurement in the mesopore range, while mercury porosimetry is better applied to the macropore range.

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