Influence of particle shape and size on the wetting behavior of soft magnetic micropowders

In the present study the effects of the particle shape, size and size distribution on the wetting behavior of soft magnetic micropowders are investigated. For this purpose, capillary rise experiments based on Washburn theory for contact angle determination were conducted using capillary rise method in standard tensiometer. Two particle materials were used—spherical Iron Silicon particles (FeSi) and irregular shaped Magnetite particles (Fe3O4) with the following particle size distributions: 0–20, 20–40, 40–63, 63–80 and 80–100 μm. Moreover, standard liquids of varying surface tensions were used to investigate the effect of liquid properties on the wetting behavior. It was found that larger particle sizes yield lower contact angles and consequently improved wetting. Similarly, with constant particle size, FeSi particles exhibit lower contact angles compared to Fe3O4 particles due to their regular particle shape. Finally, effect of liquid was such that lower liquid surface tension results in lower contact angles.