Fabrication of Al–LiAlO2 metal matrix composites and crystalline γ-LiAlO2

We report the synthesis of nano-structured LiAlO2 network in an Al-based metal matrix composite (MMC) by sintering a powder compact of Al–15 wt.%Li2O. The morphology of the in situ formed network in the Al matrix was similar in all the samples prepared at temperatures between 300 °C and the arc-melting temperature. However, it was found that the LiAlO2 was initially amorphous when the MMC sample was prepared at temperatures below ∼700 °C, but it would be completely converted to crystalline γ-phase LiAlO2 by sintering at 1000 °C. The MMCs had made nano-porous by removing the Al matrix with NaOH solution. The sizes of pores were determined to be about 130–230 nm and the width of the branches of the γ-phase lithium aluminate (γ-LiAlO2) network were about 50–100 nm.