The triclinic high temperature modification of the alpha phase of the Zn-Al system

The structure of the beta phase of the Zn-Al system was reinvestigated. The X-ray diffraction (XRD) pattern of the Zn-21.8wt%Al after 9 h at 350 degre es C clearly showed the splitting of some Bragg peaks. The triclinic struct ure permits a description of the spectra with a = 285.857, b = 285.283, c = 285.847 pm, alpha = 59.602 degrees, beta = 59.869 degrees, gamma = 59.716 degrees. This structure corresponds to a small distortion of the primitive R cell of the high temperature fee solid solution alpha-(Al) when the Zn co ntent reaches about 69.5 wt% at 350 degrees C. (C) 2000 Elsevier Science Lt d.