Helium bubble evolution in ion irradiated Al/B4C metal metrix composite

Helium behavior in Al/B4C metal matrix composite with two different sets of ion irradiation conditions has been investigated by transmission electron microscopy. Helium bubbles in Al were found to be much larger than those in B4C after a helium fluence of 1.5 × 1017 ions/cm2 at the room temperature. Also, bubbles at grain boundaries and their vicinity in aluminum are faceted. With additional proton irradiation, a bubble denuded zone along the aluminum grain boundary appears. The results are discussed in terms of the energetics of the material system.

Scheme of combined irradiation includes a pre-implantation of 400 keV He+ to 1.0 × 1016 ions/cm2 followed by a 1.5 MeV proton irradiation to 2.2 × 1019 ions/cm2 on the perpendicular surface. TEM samples were prepared by FIB. The area suffered with both He+ pre-implantation and proton irradiation was marked as light blue.Figure optionsDownload high-quality image (50 K)Download as PowerPoint slide