The Improvement of the Irradiation Resistance of Amorphous MoS2 Films by Thermal Annealing

Abstract

Among the structural materials used in fusion reactors, amorphous materials can effectively inhibit the accumulation and growth of radiation-induced defects, thereby improving irradiation resistance. However, the application of solid lubricating materials should also consider the changes in their lubricating properties after irradiation. This study shows that the ability to inhibit the deterioration of lubricating properties is not reflected in the amorphous MoS2 film. When the ion fluence reached 4.34 × 1014 ion/cm2, its wear life was reduced by two orders of magnitude, reaching 8.2 × 103 revolutions. After the amorphous MoS2 film is vacuum annealed, its structural stability and resistance to deterioration of lubricating properties are improved. When the ion fluence reaches 1.09 × 1015 ion/cm2, for instance, the wear life of the MoS2 film annealed at 300 °C remains at 8.4 × 104 revolutions. The higher irradiation tolerance of MoS2 films comes from the reduction in intrinsic defects by thermal annealing, which increases the internal grain size and volume fraction of grain boundaries, further providing an effective sink for irradiation defects.