Highlights

Radiation Damage of Potential Nuclear Materials

Scientific Achievement

Materials based on Ti₃AlC₂ and Ti₃SiC₂ have shown potential as materials for application in high temperature and pressure environments.  These materials have properties that cross the traditional metallic-ceramic divide, as they have advantageous high temperature properties; while at the same time retain oxidative resistance, traditional properties of ceramics.  In addition to these they are machinable and ductile, traditional properties of metals.  As such these materials can be thought of as hybrids between ceramics and metals.  This hybrid nature makes them ideal candidates for use in both future fusion and Gen4 reactor technologies as potential reactor core lining materials.  However, in order for these materials to be used the effects of radiation in such extreme environments need to be understood.  As part of this process Ti₃AlC₂ and Ti₃SiC₂ have both been irradiated using the IVEM-TANDEM.

Samples of Ti₃AlC₂ and Ti₃SiC₂ were irradiated at 300K with 1 MeV Kr²⁺ ions and showed similar results, they both showed very little damage up to levels of 3.75x10¹⁵ ions cm^-2 (~12 dpa).  Diffraction images from Ti₃SiC₂ showed evidence of an amorphous phase, while the images showed evidence of annealing within the structure.  Ti₃AlC₂ on the other showed significantly less damage.  In both cases however, the materials retained their shape and morphology.

Significance

Both sets of samples have shown that these materials have both very high tolerance for irradiation damage, and have potential use in future nuclear technologies.  Further experiments are planned using ion beams of different energy and composition e.g. Xe+ at 500KeV to discover whether it is possible to drive these materials to amorphisation.  This is in combination with both structural simulations and other bulk irradiation studies to examine the creep resistance of such materials.

Although this work is in the early stages it has been presented at the Materials for Future Fusion and Fission Technologies symposium held at the MRS Fall Meeting in Boston 2008.

Performers

K. R. Whittle, K. L. Smith, M.G. Blackford (Institute of Materials Engineering, ANTSO, Australia); N. J. Zaluzec (Argonne-MSD)