## High resolution electron microscopy of split patterns in Ni-base superalloys

### August 8, 2007

Title: Statistical analysis of $\gamma^{\prime}$ quartet split patterns in $\gamma-\gamma^{\prime}$ Ni alloys revealed by high resolution electron microscopy

Authors: H. A. Calderon; C. Kisielowski; T. Mori

Abstract: The frequencies of adjacent $\gamma^{\prime}$ pairs having in-phase and out-of-phase relationships in quartet configurations, determined by high resolution electron microscopy [Calderon et al., Phil. Mag. Lett. 85 51 (2005)], were examined in detail for $\gamma^{\prime}$ particles belonging to the same translational order domain. Consequently, there were always at least two out-of-phase adjacent pairs in any quartet. It is concluded that the quartet split patterns in $\gamma^{\prime}$ particles, but are produced by the migration of particles due to diffusion, these particles having been precipitated separately and independently prior to migration. An elasticity calculation is provided to show that two $\gamma^{\prime}$ particles migrate to align along <100> when their initial position deviates from this direction.