The structure of planar precipitates in B-containing alloys was analyzed by using 2-beam transmission electron microscopy. The precipitates were shown to be non-conservative substitutional complex faults that arose from the replacement of Al by B. The faults were located on {001} planes, with a displacement vector of the form, 1/8[40¯1] + 1/8[00δ], where δ was a small number. The crystallography of the planar fault was related to the crystallography of ternary borides of the form, Aln-1XnB2.

Transmission Electron Microscopy Study of Complex Planar Faults in Ru-Al-0.5at%B. D.C.Lu, M.De Graef, T.M.Pollock: Philosophical Magazine, 2004, 84[22], 2317-29