Local/Global Measurement of Primary Dendrite Arm Spacing in Single Crystal Nickel-Based Superalloys

Tschopp, M. A., Oppedal, A. L., & Solanki, K.N. (2015). Local/Global Measurement of Primary Dendrite Arm Spacing in Single Crystal Nickel-Based Superalloys. 2015 TMS Annual Meeting and Exposition. Orlando, FL: TMS.

Characterizing the spacing of primary dendrite arms in directionally-solidified microstructures is an important step for developing process-structure-property relationships by enabling the quantification of (i) the influence of processing on microstructure and (ii) the influence of microstructure on properties. The research objective herein is to evaluate the capability of various conventional approaches, as well as new or modified approaches, for spatial point pattern analysis with application to characterizing experimental dendritic microstructures. Both computer-generated and experimental dendritic microstructures are used for this analysis along with numerous techniques based on nearest neighbor spacing, Voronoi tessellation, Delaunay triangulation, or graph theory. Comparison of new metrics with traditional primary dendrite arm spacing metrics will also be discussed for both local and global measures. The current methods investigated will supply information of local spacing and coordination number while addressing edge effects, parameter sensitivity, and correlation with interdendritic features, thus providing insight into how processing affects properties.