CW614N, round bar, d=22 mm

1.3.1 Light microscope images

Images of etched specimen at 100, 200, 500 and 1000 times magnification. The duplex brass microstructure can be seen with distinct difference in etch response between the two phases. Alpha phase appears bright and beta phase darker. Lead particles are etched dark. The beta phase is etching different in some grains, this could be an crystallographic effect. Grain boundaries in the beta phase are visible to some extent.

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.

CW614N, 100x Magnification

CW614N, 200x Magnification

CW614N, 500x Magnification

CW614N, 1000x Magnification

Composition of CW614N

1.3.2 EBSD/EDS analysis in the SEM

EBSD analysis with 1 µm step size

The material show a fine grained duplex microstructure consisting of alpha-beta phase, and lead particles. In this limited area it is difficult to make assumptions about texture.

Specimen surface was parallel with extrusion direction (X=ED). Position ¼ depth.

Surface was OP-S-polished.

FSD image of the area for EBSD analysis. Streaks of Pb particles along ED is seen.

IPF-Z EBSD map with colours according to crystal orientations in Z direction (transverse dir.).

EBSD phase map, alpha phase is red and in beta phase is blue.

IPF in X direction (extrusion dir.). Grain boundaries (>15°) and low angle boundaries (2-15°) are included.

Alpha phase crystal orientations (ED)

Beta phase crystal orientations (ED)

Grain- and phase boundaries

In this material there is a tendency to have low angle boundaries. Some twins seem to have been rotated away from the ideal twin relation. And in the previous IPF maps there are shifts of colour within grains. The assumption would be that some plastic deformation occurred after recrystallisation during extrusion.

Phase boundaries are light blue (aqua). Grain boundaries (>15°) are black. Low angle boundaries (2-15°) are thin black. Twin boundaries (60°<111>) are red.

EDS mapping in parallel to EBSD analysis

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1.3.3 Higher magnification analysis

EBSD analysis with 0.25 µm step size

The material show a fine grained duplex microstructure consisting of alpha-beta phase, and lead particles. Some plastic deformation remain in the microstructure.

Specimen surface was parallel with extrusion direction (X=ED). Surface was OP-S-polished.

FSD image of the area for EBSD analysis. Lead particles are seen, stretched along ED.

IPF-Z EBSD map with colours according to crystal orientations in Z direction (transverse dir.).

EBSD phase map, alpha phase is red and in beta phase is blue. Grain boundaries (>15deg) are included.

EBSD map show IPF in X direction (extrusion dir.). Grain boundaries (black) and twins (red) are included in the image.

Grain- and phase boundaries

Same description as before, we see in this material a tendency to have low angle boundaries. Some twins seem to have been rotated away from the ideal twin relation. And in the previous IPF maps there are shifts of colour within grains. The assumption would be that some plastic deformation occurred after recrystallisation during extrusion.

Phase boundaries are light blue (aqua). Grain boundaries (>15°) are black. Low angle boundaries (2-15°) are thin black. Twin boundaries (60°<111>) are red.

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 figures for both phases show textures for the alpha phase <100>&<111>//ED, and for the beta phase <110> // ED.