THE TRICLINIC HIGH TEMPERATURE MODIFICATION OF THE a PHASE OF THE Zn-Al SYSTEM

摘要

The structure of the B phase of the Zn-Al system was reinvestigated. The X-ray diffraction (XRD) pattern of the Zn-2l.8wt/100Al after 9 h at 350 C clearly showed the splitting of some Bragg peaks. The triclinic structure permits a description of the spectra with a = 285.857, b = 285.283, c = 285.847 pm, a = 59.602 B = 59.869 γ = 59.7l6 This structure corre- sponds to a small distortion of the primitive R cell of the high temperature fcc solid solution a-(Al) when the Zn content reaches about 69.5 wt/100 at 350 C.