Neutron Scattering

1990
1994
1996
Fig. 18.23 : Experimental neutron polefigures ofa rolled (left) and a recrystallized (right)
copper specimen in 1990, 1994, and 1996 without any treatment in between
The textures, quantitatively analysed by model calculations are found unstable over
the time of investigation . All quantitative results are summarized in Table 1 . The initially
almost complete rolling texture recedes by about 30% in sample volume in favour of
recrystallization . In the recrystallized specimen, the initial amount of recrystallization texture
is reduced from 89% to 66% in favour of a randomly oriented portion . The somewhat
surprising fmdings of living textures` are remarkable wich respect to the kinematics of the
physical processes involved, and also with respect to the desired longtime stability ofmaterial
properties in technological applications .
Table 1 : Longtime variations of the texture of rolled (top) and recrystallized copper (bottorn)
as rneasured by neutron diffraction and analysed by the component method using theprogram
MULTEX [101. Texture parameters are given in Vol% of the main components . The
orientation deviations ofthe crystallitesfrorn the various fibre axes are given by thefull width
at halfmaximum (FYVHIVI) of Gaussian distributions .
Rolled Cu-specimen
Com onent S" co er" ,brass" ,cube"
Year Vol % FWHM Vol % FWHM Vol % FWHM Vol % FWHM
1990 36 13 24 11 22 13 3 10
1994 27 13 19 11 20 13 21 il
1996 24 13 15 11 17 13 28 il
Rec stallized Cu-s~jecimen
Component ,cube" {112} random
Year Vol % FWHM Vol % FWHM Vol
1990 61 9 28 13 11
1994 54 10 32 11 14
1996 50 9 16 11 34
18- 16