Local flame structure analysis of NH3 and blends with CH4 and H2 was conducted upon spherical expanding flames, facilitated by the use of Mie-scattering tomography. The wrinkling ratio was found to increase with both increasing NH3 fraction and turbulent intensity, in agreement with observed flame geometries. Results show that the local curvature pdf of the pure NH3 flame shifts towards greater local zero curvature with increasing eddy turn over time. In general, the mean curvature is positive for all examined flames, with an increase in turbulence intensity resulting in a widening of the curvature distribution, in agreement with measured wrinkling ratios.