Solidification microstructure of Cu–Cr and Cu–Cr-In alloys

Abstract

Solidification microstructure of Cu-Cr and Cu-Cr-In alloys has been characterized using scanning electron microscopy in the present work. Thermodynamic database has been established for the Cu-Cr binary system and Cu-Cr-In ternary system. Solidification behaviors of the two alloys have been simulated using the thermodynamic parameters based on Scheil model. The results show that the primary Cr phases with long and thin dendrites can be observed between Cu matrix grains for the Cu-Cr alloy, and the 'flower-like' coarsen dendrites primary Cr phases of the Cu-Cr-In alloy exist in the triangular grain boundary areas. The weight percent of indium element in the liquid phase of the Cu-Cr-In alloy during solidification continuously increases up. This will enlarge the solidification temperature range from 6°C to 214°C resulting in longer time for the dendrite growth and the alloying element indium with low melting point tends to segregate to the grain boundary region.

Effects of Zn addition on the microstructure and properties of Cu–Cr alloys

“…Cu-Cr alloy requires to further enhance the recrystallisation and softening temperature, which would be used to manufacture room temperature and hightemperature conductive wear-resistant parts [19]. However, traditional Cu-Cr alloys have poor resistance to softening at high temperatures, which is challenging to meet the needs of industry [20][21][22]. Moreover, the conductivity and ultimate tensile strength of copper alloys were limited to around 80% IACS and 500 MPa for this significant research field [23][24][25].…”