Optimization of dry powder deposition parameters for the production of dielectric and magneto-dielectric composites

Spatially variable composites of Calcium Magnesium Titanates(CMT) with dielectric permittivity 15, 20 and 70 and commercial ferrite were produced by Dry Powder Deposition (DPD) method followed by cosintering at elevated temperatures. Thermogravimetric analysis of each constituent powder was used to analyze efficient removal of 1-3 % binder content of spray dried ferrite and CMT powders and achieve complete sintering of their textured composites. Smooth, monolithic dielectric and magneto-dielectric textured composites were obtained by cosintering at 1450 C for 4 hours that were compacted at 50 bar in a 12*13 grid with 3 mm pixels and a thickness of 5mm. We reduced thermal mismatch effects of constituents observed at temperatures below 1450 C and prevented cracks and unwanted defects such as porosities in textured composites. Density measurements and SEM stressed that we finally obtained over >%98 dense ceramic constituents. Microstructural characterizations of pellets made of sintered constituent material were carried out by SEM. We present in this paper that textured monolithic dielectric and magneto-dielectric composites of various shades could be produced by DPD method which is an efficient way for production of spatially variable multimaterial dielectric substrates suitable for various antenna and filter applications.