Effect of Pb in FRHC copper: Phase diagram and solidification studies

The thermodynamic aspects of the copper rich part of Cu-O-H-Pb system involved in the production of fire-refined high conductivity (FRHC) copper was analyzed. A simplified approach was adopted for the description of thermodynamic equilibrium of the system in order to realize the equilibrium diagrams relevant to copper casting process. A strong association model was considered for the condensed phases. A qualitative view of the role played by lead incorporated in trace amounts in the Cu-O-H alloys as obtained. The solidification path was presented as a function of several casting parameters and the final microstructure of the ingot was analyzed.