Ultrafine AlN and Cr2N composite particles prepared by reaction between nitrogen plasma and molten Al-Cr alloys

Ultrafine ceramic composite particles with a matchstick-like shape consisting of hexagonal AlN and Cr 2 N phases were found to form at approximately 100% fraction by the reaction between nitrogen plasma and molten Al 50 Cr 50 liquid. The AlN phase has a hexagonal prism shape with a transverse size of about 50 nm and a length of about 200 nm while the Cr 2 N phase has hexagon-pyramids with an edge size of about 100 nm and connects with the AlN hexagonal prism. The two phases have a close crystal orientation relationship of [001] AlN / [001] Cr2N and [110] AlN / [100] Cr2N which has low misfit strains of about 11 %