Inoculation of copper alloys

Abstract

Copper alloys are important in the manufacturing of metal products that require good corrosion resistance and/or high thermal and electrical conductivity. The properties of these alloys for service or mechanical processing are closely related to their as-cast grain structure. The grain refining of this grain structure can be achieved by inoculation of the melt before solidification, increasing the number of nuclei in the liquid and decreasing the average final grain size. Published research studies about the inoculation process and grain refining mechanisms for copper alloys are scarce and insufficient to allow for the design of commercial inoculants for copper alloys. The main objective of the present research project is the identification of the fundamental mechanisms of inoculation and grain refinement in commercially pure Cu, Cu-Sn and Cu-Zn binary alloys through controlled additions of alloying elements, such as, Fe, Zr, B, and C. The identification of these mechanisms will be studied by several characterization techniques: (a) thermal analyses (DTA and DSC); (b) microanalysis (EDS, WDS); (c) metallographic techniques combined with optical and electron microscopy (SEM) with field emission gun (FEG) and electron backscattered diffraction (EBSD). The results and conclusions obtained in this project will enable the identification of fundamental mechanisms of inoculation that will assist in the design of commercial inoculants for copper alloys. (AU)