Amorphisation of boron carbide under gamma irradiation.

Abstract

Boron carbide (\(\hbox {B}_{\mathrm {4}}\hbox {C}\)) has been widely used in nuclear reactors and nuclear applications. In this work, the high-purity (99.9%) \(\hbox {B}_{\mathrm {4}}\hbox {C}\) samples were irradiated using a gamma source (\ (^{\mathrm {60}}\hbox {Co}\)) with a dose rate (D) of 0.27 Gy/s at different gamma irradiation doses at room temperature. Phase and microstructural characterisation of \(\hbox {B}_{\mathrm {4}}\hbox {C}\) samples were carried out using X-ray diffraction (XRD) and scanning electron microscopy (SEM). XRD results displayed some degradation of the diffraction peaks. The calculations reveal that 62% of \(\hbox {B}_{\mathrm {4}}\hbox {C}\) has changed into the amorphous phase when the irradiation dose is 194.4 kGy. Fourier transform infrared spectroscopy (FTIR) was used to explain chemical bonds and functional groups of \(\hbox {B}_{\mathrm {4}}\hbox {C}\) samples before and after gamma irradiation. The results showed that C– C chemical bonds are weaker than B–C chemical