A simple and accurate method of determining the habit planes from the deter
mination of beam and habit plane trace directions using Kikuchi line diffra
ction patterns and the measurement of the thickness of the thin foil has be
en developed. The thickness of the thin foil can be calculated from the mea
surements of the widths of the habit plane trace at two different positions
. The first orientation is with the foil normal to the electron beam (zero
tilt) and the second one is where the foil has been tilted by a known amoun
t about an axis parallel to the original trace at zero tilt. From the beam
and the trace directions and thickness of the thin foil, the indices of the
habit plane normal may be calculated. The technique has been tested using
{111} annealing twin interfaces in stainless steel and shown to be capable
of determining habit planes to within a degree or two. Extension of this me
thod to the measurement of martensite habit planes is described. (C) Elsevi
er Science Inc., 1999. All rights reserved.