3D gel-printing of Sr ferrite parts

Abstract 3D gel-printing (3DGP) opens new possibilities to process complex-shaped Sr ferrite parts for magnetic applications. In this study, a novel 3DGP process based on the hydroxyethyl methacrylate gelation system was employed to prepare complex-shaped Sr ferrite samples. To obtain highly loaded pseudo-plastic slurries, the Sr ferrite powder was modified by 1 wt% silane coupling agent and 2.5 vol% polymer Silok7050S was introduced into the ceramic slurry as a dispersant. In the printed samples, good dimensional accuracy and surface quality were achieved with a relatively low surface roughness of 5 µm. After sintering, the Sr ferrite ceramics exhibited good surface quality and the surface roughness was 3.2 µm. A homogeneous microstructure was observed. The bending strength for the sintered samples with the relative density of 97% was 83 MPa. In addition, the corresponding coercivity, remanence, and maximum magnetic energy product values were 271.2 kA/m, 0.383 T, and 26.34 kJ/m3, respectively.