You are given three different materials and told one is a single crystal ceramic

Question

You are given three different materials and told one is a single crystal ceramic, one an amorphous polymer and an amorphous material. The following instruments are available to you: an SEM, an X-ray diffraction system, an optical microscope, a tensile tester, and a multimeter. Based on what you have learned about the structure and properties of materials over the course of this term, describe the specific measurements/tests you would carry out to unambiguously determine which material is which. Be very precise in your answer?

Explanation / Answer

In order to use X-ray diffraction system, first is good idea to do a SEM of all the samples. In that way you can see if there are particles and what size there are, because X- ray diffraction only is reliable about crystallinity if particle size is in a size range. For that you have to obtain powder of the samples and can determine its size by optical microscopy.

X-ray diffraction will discard the two amorphous materials because this technique gives information about cristallinity of the sample. You have to observe peaks for the ceramic sample only.

The tensile test is useful for distinguish polymeric and non polymeric materials.   For undrawn polymers, heating increases the tensile modulus and yield strength, and reduces the ductility - opposite of what happens in metals. The Elongation and Percent Elongation at yield and Elongation and Percent Elongation at break will help also to differentiate them. The non polymeric material will not elongate as much as a polymeric one.

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