O-lattice analyses of interfacial misfit. II. Systems containing invariant lines

Abstract
Mismatch in interfaces containing an invariant line is analysed on the basis of the O-lattice concept and the properties of the invariant line strain. An optimum orientation relationship is proposed to satisfy the requirement for the existence of the O lines. The corresponding habit plane will contain the O lines, and the mismatch in the habit plane will be accommodated completely by a single set of dislocations. The concept of an effective invariant line is introduced. An example is given for a Zr-2.5 wt% Nb alloy, showing the method of search for the optimum orientation relationship. The corresponding interfacial structure in the habit plane is also provided.