Simultaneously enhancing the strength and ductility of Cu-Ti-Fe alloy through electric current pulse induced precipitation

Abstract

Cu-Ti alloys are key materials for use of next-generation high-strength elastic components to replace hazardous Cu-Be alloys, but the tensile strength and ductiltiy are difficult to cooperative control through the conventional aging treatment. In this study, we successfully induced an electric current pulse (ECP) to promote the nucleation and precipitation of metastable phases during the fabrication of Cu-Ti-Fe alloy. It is noteworthy that a large quantity of the nanoscale β'-Cu₄Ti phase rapidly precipitated under an extremely short electropulse duration (90 s). After further aging, higher density and finer β'-Cu₄Ti precipitates were detected in the matrix, which significantly hindered the occurrence of discontinuous precipitation (DP) behavior. Compared with traditional aging treatment, the tensile strength and elongation of alloy with ECP and aging increased by 103 MPa and 8%, respectively. These results provide guidance for the simultaneous strength–ductility enhancements of various metallic materials.