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Schematic <200> pole figures
Select a material
Select a processing route
Wire
Rolled
Annealed
Select a processing route
Wire
Rolled
Annealed
Click on the pole figure to find out more
In a cold-drawn wire, a texture arises in which most of
the grains aligns
so that they have a common crystallographic direction parallel to the
wire axis. However, they can have any rotational position about that axis.
so that they have a common crystallographic direction parallel to the
wire axis. However, they can have any rotational position about that axis.
This is known as fibre texture and the axis of the wire
is known as the fibre axis
In
bcc metals, the fibre texture is a simple [110]
Silver
Aluminium
Rolled sheets tend to develop complex textures with a
spread of orientation
distributions. Pole figures are often ambiguous and so multiple pole figures
may be necessary to identify preferred orientations
distributions. Pole figures are often ambiguous and so multiple pole figures
may be necessary to identify preferred orientations
Roll over to show preferred
orientation:
(110)[112] (112)[111]
(110)[112] (112)[111]
Rolled
textures are described by ideal orientations. These
are
approximations of the preferred orientation and are given in the
form:
(hkl)[uvw]
where:
(hkl) is a plane that lies parallel to the plane of the sheet
[uvw] is a direction parallel to the rolling direction.
approximations of the preferred orientation and are given in the
form:
(hkl)[uvw]
where:
(hkl) is a plane that lies parallel to the plane of the sheet
[uvw] is a direction parallel to the rolling direction.
A Wulff net can be used to explain the 12 minor reflections
which arise in this pole figure
Twinning in copper arises
from reflections in {111} planes
Twinning in copper arises
from reflections in {111} planes
The net is then used
to work out the angle
between 00 and the
pole T common to this
great circle and that
of (111)
to work out the angle
between 00 and the
pole T common to this
great circle and that
of (111)
r' is related to r and
n by the expression \[\mathbf{r}' = \mathbf{r} - 2\frac{\mathbf{r}.\mathbf{n}}{\mathbf{n}.\mathbf{n}}\mathbf{n} \] r' is found to be 1/3[22]
n by the expression \[\mathbf{r}' = \mathbf{r} - 2\frac{\mathbf{r}.\mathbf{n}}{\mathbf{n}.\mathbf{n}}\mathbf{n} \] r' is found to be 1/3[22]
The angle between 00
and pole T is 35.3°
and pole T is 35.3°
To find the 22 pole, 35.3°
should be measured from pole T towards
the 111 pole
should be measured from pole T towards
the 111 pole
1
22
22
Trace of (111)
110
111
T
T
T
Micrograph of
copper showing annealing twins