Correlation of Hardening and Microstructure of Tantalum Irradiated with Heavy Ions

摘要

The microhardness change of tantalum irradiated with heavy ions has been evaluated using a micro-indentation technique. The increase in hardness by irradiation was significant below approx900K and negligible above approx1100K. The hardness decreased steeply with temperature at approx1000K. Correlation of the results with microstructure data showed that the strength of voids and line dislocations as barriers against deformation should be very weak relative to that of loops and TEM-invisible defects. The temperature and fluence dependence of the hardening by TEM-invisible defects, derived by the correlation, implied an accumulation process of cascade vacancy clusters during irradiation.