Influence of the dispersants in gelcasting of nanosized TiN

The gelcasting process for shaping of plasma synthesized nanosized TiN with regard to the dispersion behaviour and the resultant microstructures has been investigated. The dispersion behaviour of the powder and rheology of the slurries under the influence of three different dispersants have been studied as a function of pH. Solid content of the slurries was up to 22 vol%. The isoelectric points as measured by the streaming potential method were found to be at a pH of 3.7 and lower. Sintering of the dried and debindered green bodies was carried out in a N-2 atmosphere with the application of 50 bar gas pressure in the final sintering stage leaning to densities of 95.5%. Resulting microstructures are strongly dependent on the dispersant used. (C) 1996 Elsevier Science Limited.