Researchers from K. U. Leuven and the Institute of Ceramics and Glass (ICV-CSIC) have reported the innovative use of carbon nanotubes to create complicated miniaturized ceramic parts.

One promising technique for creating smaller mechanical components is electrical discharge machining (EDM), which uses a spark of electricity to blast away the unwanted material to create complex shapes. However, this method requires that the target material be electrically conductive.

By implanting carbon nanotubes in silicon nitride (the most promising high-temperature structural ceramic), the researchers were able to increase the electrical conductivity of the material by 13 orders of magnitude, changing from highly insulating to conducting. That allowed them to use EDM to produce a microgear without compromising production time or quality, while improving wear resistance.

The smaller components can be used in microturbines, microreactors, and bioimplants, for example.

Ref.: Olivier Malek, et al., Carbon nanofillers for machining insulating ceramics, Materials Today, 2011; [DOI:10.1016/S1369-7021(11)70214-0] (free access)