Influence of the structure of charge billets, overheating, and holding time of melts on the properties of Al-5 wt % Cu alloys in liquid and solid states

Abstract

The influence of the structure of charge bars, overheating temperatures, and isothermal holding time of Al-5 wt % Cu melts on their properties in solid and liquid states is investigated. It is revealed using the express method that the density of melts prepared from fine-crystalline charge bars (F-c charge) has reduced values compared with the melts prepared from coarse-crystalline charge bars (C-c charge). This peculiarity is retained over the entire studied range of overheating temperatures (760–1060°C). The influence of the structure of initial charge bars manifests itself in the second generation (after melting and crystallization from the corresponding overheating temperatures): alloys fabricated from the F-c charge have a smaller dendritic parameter α-Al and increased density and electrical conductivity compared with the alloys made from the C-c charge. It is shown that the involvement of deformed aluminum and copper waste into the charge composition provides a finely dispersed structure and increased density of Al-5 wt % Cu alloys in the solid and liquid states.