QUALITATIVE AND QUANTITATIVE INDICATORS  OF RAPIDLY SOLIDIFIED ALLOYS OF THE AL-ZN-MG-CU SYSTEM MODIFIED BY ZIRCONIUM

Samples of a rapidly solidified Al-Zn-Mg-Cu alloy modified by zirconium were obtained. An amorphous layer which did not exceed 9% of the total volume of the sample was discovered on the sample surface that was in direct contact with the cool ambient. This layer is a compound material consisting of an amorphous matrix and inclusions of intermetallic Zr3Al, Zr2Al, ZrAl2 and ZrAl3 compounds, wherein ZrAl3 is the strengthening phase with particle sizes ranging from 5 to 30 nm. Amorphization of the whole volume of the alloy with added zirconium as an alloying component allows to obtain an almost uniform distribution of intermetallics in the amorphous matrix. The total number of Al-Zr intermetallics decreases with an increase in zirconium content above 1.5 wt%. When this happens, a significant growth of Al grain can be observed, which is evidence of the further increase in the content of zirconium as the alloying component.