A simple and inclusive method to determine the habit plane in transmission electron microscope based on accurate measurement of foil thickness

• An improved algorithm is formulated to measure the foil thickness.
• Habit plane can be determined with a single tilt holder based on the new algorithm.
• Better accuracy and precision within ± 1° are achievable using the proposed method.
• The data for multi-facet determination can be collected simultaneously.

A simple and inclusive method is proposed for accurate determination of the habit plane between bicrystals in transmission electron microscope. Whilst this method can be regarded as a variant of surface trace analysis, the major innovation lies in the improved accuracy and efficiency of foil thickness measurement, which involves a simple tilt of the thin foil about a permanent tilting axis of the specimen holder, rather than cumbersome tilt about the surface trace of the habit plane. Experimental study has been done to validate this proposed method in determining the habit plane between lamellar α2 plates and γ matrix in a Ti–Al–Nb alloy. Both high accuracy (± 1°) and high precision (± 1°) have been achieved by using the new method. The source of the experimental errors as well as the applicability of this method is discussed. Some tips to minimise the experimental errors are also suggested.