Preparation of tritium breeding Li2TiO3 ceramic pebbles via newly developed piezoelectric micro-droplet jetting

Wet methods as an emerging technique for the preparation of millimeter-sized tritium breeding ceramic pebbles, but the imposed air pressure as the driving forces to extrude slurry droplets are fluctuating during the reciprocating extrusion process, which caused a slight inconsistency in pebble sizes. In this study, a piezoelectric micro-droplet jetting approach was proposed by introducing a piezo-driven valve and modifying the slurry barrel mechanism to realize the air pressure invariable. A self-developed piezoelectric micro-droplet jetting device was successfully utilized to prepare Li2TiO3 green pebbles with coefficients of variation being lower than 2.7%. The size of the green pebbles could be precisely controlled in the range of 0.88-1.37 mm by manipulating the nozzle diameter, the air pressure, and the jetting time. The pebbles sintered at 1000 degrees C for 3 h possessed a small grain size of similar to 5.9 mu m, a satisfied relative density of similar to 84.8% T.D., and a high crush load of similar to 25.7 N, implying the prepared pebbles could be used as a promising solid tritium breeding material in fusion reactors. These findings are anticipated to provide new opportunities for the highly efficient preparation of size-controllable tritium breeding ceramic pebbles.

Automated summary

In this study, a piezoelectric micro-droplet jetting approach was successfully utilized to prepare size-controllable Li2TiO3 green pebbles with low coefficients of variation. The size of the green pebbles could be precisely controlled in the range of 0.88-1.37 mm by manipulating the nozzle diameter, the air pressure, and the jetting time. The sintered pebbles exhibited small grain size, satisfactory relative density, and high crush load, indicating their potential as solid tritium breeding materials in fusion reactors.