1.6.1 Light microscope images
Images of etched specimen at 100, 200, 500 and 1000 times magnification. Single phase brass microstructure with grains aligned in the ED. The etch effect is rather homogeneous in this case, but twins can be distinguished at higher magnifications due to etching of crystallographic orientations. Large grains have different orientation compared to the smaller, as learned from EBSD. Lead particles are etched dark, they appear to be round and homogeneously distributed.
Etching: 5g ferric chloride + 10ml conc. hydrochloric acid + 100 ml de-ionised water.
Specimen surface was parallel with extrusion direction (X=ED). Position ¼ depth.
Composition of CW625N
1.6.2 EBSD/EDS analysis in the SEM
EBSD analysis with 1 µm step size
The material show a fine grained homogeneous microstructure consisting of alpha phase, and lead particles. In this limited area it is difficult to make assumptions about texture but <100> (red colour) and <111> (blue) orientations // ED dominates. Specimen surface was parallel with extrusion direction (X=ED). Position ¼ depth. Surface was OP-S-polished.
Grain- and phase boundaries
In this material there are not a lot of low angle boundaries. The assumption would be that recrystallisation occurred after extrusion.
Grain boundaries (>15°, black), low angle boundaries (2-15°, gray), and twin boundaries (60°<111>, red) are included in the image.
EDS mapping in parallel to EBSD analysis
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Large area mapping – Many (>40) analyses stitched together
The large area make statistics for grain size, phase fractions, texture, etc. better and now it is obvious that there are preferred orientations in X (ED).
Pole figure shoing texture components for the alpha phase, strong <100>//ED (38 times random) and weaker <111> // ED.
Grain size, area weighted distribution
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