The Effect of Neutron Irradiation on the Mechanical Properties of Advanced Silicon Nitride Nanocomposites

摘要

There is a continuous need to develop structural and functional components to sustain fusion plasma under the very severe environment such as intense radiation or high temperature in fusion reactors. The reference Si_3N_4 and novel Si_3N_4 based nanocomposites with carbon nanotube, graphene or carbon black additions were irradiated in a controlled-temperature irradiation rig inside the Budapest Research Reaktor (BRR) at a temperature of 270 °C. In the irradiation channel of BRR the l,5 X 10~(13) n/cm~2 fluence can be reached in 700 hours. The effect of the neutron radiation on the mechanical properties of Si_3N_4 based nanocomposites with different carbon additives was investigated. In the case of 3-point bending test graphene and carbon nanotube added samples showed an increase in strength ~100-300 MPa after irradiation. 4-point bending strength measurements resulted in a significant increase of strength in the case of reference samples ~200-400 MPa and carbon nanotube added composites ~200-300 MPa after irradiation. Other samples showed no change in strength after irradiation.