Construction of iso-concentration sedimentation velocities using Z-axis translating laser light scattering

The development of functionally gradient microstructures is an important materials process design enhancement. But model verification of functionally graded microstructures depends on generating usable dynamic iso-concentration sedimentation profiles that are often difficult to obtain using metal matrix composite microstructures or even simpler liquid models. Here, we show results on dispersion settling similar to other published dispersions using a Z-axis translating laser light scattering (ZATLLS) unit. Model experiments tracked sedimentation velocities of a dispersion of 10 wt.% ground glass spheres in water. A calibration curve of transmitted light versus concentration was constructed and as a result, iso-concentration sedimentation velocities can be inferred given the generation of discrete data at millimeter level translational resolution. The results indicate that there is a subtle difference in the iso-concentration sedimentation velocities ranging between 0.19 and 0.24 μm s −1 for mass fractions between 0.1 and 0.3 mass% of glass particles in solution. The particle size distribution led to different gradients at the different mass fractions.