Usually, after heat treatment at high temperature, ceramics will be faced with a problem of shrinkage. The geometry of of our samples are tablet ( diameter= 13mm, H=2mm)
Armin,
Shrinkage, at least, the contraction in one dimension can be measured with simple mechanical tools - calipers and so on.
If one is attempting to make highly accurate measurements then optical methods may be necessary, such as holographic or interferometric methods.
If you are trying to measure shrinkage *during* the firing process, then optical methods would be essential (but still challenging).
May I ask as to what your exact problem is? Certainly, ceramics will distort during firing - are you trying to measure the extent of those changes *after* firing or during?
Shrinkage of ceramics after heat treatments can be done by simple dimensional technqiues, rulers, calipers etc.
In addition, delatometer can be used for measuring coefficient of thermal expansion [CTE] using heating and cooling mode. Repeated experimentation enables determination net unchangable dimension upon repeated heat treatments.
Armin,
There is an instrument called 'Dilatometer' specifically made for this purpose.
I hope the article in the following link will be of your help.
http://www.doiserbia.nb.rs/img/doi/0350-820X/2008/0350-820X0802117M.pdf
Good luck man.....
Well, there is just one additional suggestion - the Archimedes method (buoyancy). You can dip your sample in a liquid and measure the change in its volume. Bouyancy is exceptionally comfortable as during firing, sample deforms quite often. Then regular measurement with calliper would be difficult as the shape would not be regular.
For your thin & flat sample ( dia 13mm and height 2mm), it would be better to measure the diameter before and after sintering with a caliper- at different points. Measurement of change in height (only 2mm) would be less accurate. Similarly, for dilatometry, it would be better to use diameter. But setting the thin sample would be difficult between the dilatometer pushrods.
All of the answers are really applicable. If you implemented one of them and got your expected outcome, then that's okay.
I am applying another technique in my research in order to measure shrinkage of food materials.It is simply by image analysis.Continuous or interim image of the sample can be taken and then it can be measured by an image anlysis software like Image J (free ).
I hope it will serve your problem.
For samples with simple geometries I suggest to keep the method as simple as possible (measure the diameter and height before and after sintering), as far your sample retains its shape. And at least 10 samples should be measured in order to keep a statistical minimun quality.
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