Abstract

The g-phase region of the Cu-Al binary system for aluminum concentrations between 30,8 and 38,5 at % was studied by transmission electron microscopy (TEM). The observations revealed the presence of inversion anti-phase domains (IAPD). The domains form regular arrays in two distinct configurations a) trian­gular domains with boundaries parallel to {112} planes and b) ribbon domains parallel to {110}. This IAPD structure was observed for alloys composition intermediate between those corresponding to P-type and R-type y- brass. The transition from one IAPD configuration to the other is described and the changes in mechanical properties were studied by micro-hardness measurements.