Tetragonal and Monoclinic Phase Determination with CL
Zirconium oxide is used as an example to demonstrate that CL makes it possible to determine both the tetragonal and the monoclinic phases. The monoclinic phase is luminescent, whereas the tetragonal areas remain black on the CL image.
Spectral dispersion on a blaze grid enables luminescence wave length determination for further analysis. The corresponding RGB colour can be indicated.
CL of Cement Clinkers
Initial findings regarding the application of cathodoluminescence in combination with an SEM for carrying out microstructure examinations and quantitative phase analysis of clinker cross section were published as early as 1997. /1/
These finding proved, for instance, that it was possible to distinguish between the three main phases of the Portland cement clinker, Alite (CS3), Belite (CS2) and the interphase (Aluminate + Ferrate C3A + C4AF), on the basis of their specific luminescence behaviour.
CL-FE-SEM image of a Portland cement clinker. The specific fluorescence behaviour of the different clinker phases is clearly visible.
Image editing software makes it possible to quantitatively determine the surface areas of the microstructural components in percentage on the basis of their specific brightness values. The advantages of reflected light microscopy (microstructural analysis, specification of the degree of corrosion and absorption) can be combined with automated phase quantification using image editing software.
Quantitatively determined phases in percentage in relation to the image detail using image editing software:
Alit (blue): | 44,5% |
Belit (yellow): | 36,6% |
A-F-Phase (red): | 18,8% |
Total: | 99,9% (±1%) |