Electron diffraction identification of structure types of martensite in Cu-Zn-Al alloys

Electron diffraction technique for identifying structure types of martensite in beta-Hume-Rothery alloys is described. It includes determination of the stacking sequence of the martensite of the basal planes, differentiation of the long-range ordering in martensite inherited from its parent phase (A2 type disordered; B2 type ordered; and D03, or Heusler, type ordered), and distinguishing between normal-type and modified-type martensite. In addition to the 18R1-type martensite, 12R, 6R, and 2H martensites were found in quenched Cu-Zn-Al alloys using this technique.