Microwave Sintering of 3D Printed Composites from Polymers Reinforced with Titanium Nitride Particles

The production of intricate samples from polymer-ceramic composites employing fused deposition modeling was studied. The samples were subjected to high-temperature heat treatment in microwave furnaces to yield titanium nitride ceramics. The conditions for making polymer-ceramic materials from polypropylene and titanium nitride powders and 3D printing conditions for associated intricate parts were examined. The TiN-polypropylene composite was produced at a temperature of 190 degrees C through extrusion of a previously prepared homogeneous mixture with a reinforcement content of 10, 20, 40, 46, 50, and 60 vol.% TiN. Using fused deposition modeling, a gear-shaped part made of the polymer-ceramic material was printed. The printed samples with 20 and 40 vol.% TiN were heat-treated in microwave furnaces in air in a carbon black backfill and in a nitrogen flow. Following the heat treatment in microwave furnaces, the samples preserved their initial shape. The composite samples treated in a carbon black backfill in air exhibited a porosity of similar to 38% and those treated in a nitrogen flow showed a porosity of similar to 22%. The samples subjected to microwave heat treatment in a carbon black backfill in air underwent sintering and partial oxidation. After microwave heat treatment in a nitrogen flow, the titanium nitride samples showed higher density and bimodal structure with titanium nitride grains varying from several micrometers to 400-200 nm. The microhardness of the samples heat-treated in a carbon black backfill was 6.5-8.5 GPa and that of the samples treated in a nitrogen flow was 16 GPa.