The irradiation-induced thermal conductivity changes and its correlation with microstructure was investigated in different intermetallic compounds, namely NiAl, Ni3Al, TiAl, FeAl, and Fe3Al. The samples remained unamorphized even under irradiations performed at 40 K with ~1 dpa dose. The residual state of order S = 0.13 to 0.7 was obtained for different samples using TEM diffraction patterns. The detailed microstructural investigation showed the irradiation-induced dense dislocation network in some materials. The irradiation-induced thermal conductivity changes was measured using two complementary techniques, the modulated thermoreflectance (MTR) and the transient grating spectroscopy (TGS). Both techniques showed consistent results i.e., up to 60 % reduction in thermal conductivity as a result of irradiation in some samples.
The investigation on two new samples (Zr3Al and Ti3Al) are also ongoing following the same procedure as above. These samples will be purposely irradiated to induce amorphization to understand the correlation between the amorphization and thermal conductivity.