Twinning
on Pyramidal Planes in hcp Crystals Determined
together with Other Defects by X-ray Line Profile Analysis
Levente Balogh, Géza Tichy and Tamás Ungára)
Department of Materials Physics, Institute of Physics of the Eötvös University Budapest, P.O.Box 32, H-1518 Budapest, Hungary
J. Appl. Cryst., 42 (2009) 580-591
Abstract
A systematic procedure is developed to evaluate the frequency of
{10.1}<10.
> and {11.2}<11.
> compressive twins and {10.2}<10.
> and {11.1}<.6> tensile twins together with dislocation
densities, active slip systems and crystallite size in hexagonal close packed
metals. The effect of pyramidal twinning on X-ray line broadening in hcp metals is fundamentally different
from the effect of twinning on close packed planes in fcc crystals. Therfore, the usual theoretical descriptions
developed previously for latter case cannot be used for pyramidal twinning in hcp crystals. The profile functions of
sub-profiles for this type of twinning are derived to be the sum of a
symmetrical and an antisymmetrical Lorentzian function. Sub-profiles properties
are parametrized and the parameter files are incorporated into the
convolutional multiple whole profile (CMWP) procedure. The extended eCMWP
procedure, is applied to determine pyramidal twin frequencies together with
dislocation densities, active slip systems and crystallite size in Mg deformed
at different temperatures, in commertial purity Ti deformed at high temperature
and in high-purity Ti deformed at room temperature.
Data tables for {10.1}<10.
> and {11.2}<11.
> compressive twins and {10.2}<10.
> and {11.1}<.6> tensile twins in Ti
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Stacking Faults and Twin
Boundaries in fcc Crystals Determined
by X-ray Diffraction Profile Analysis
Levente Balogh, Gábor Ribárik and Tamás Ungár
Department
of Materials Physics, Institute of Physics of the
Balogh, L., Ribárik, G. & Ungár, T. (2006). J. Appl. Phys. 100, 023512
Data tables for intrinsic,
extrinsic stacking faults and twin faults in Cu