The influence of traction speed on the microstructure and properties of vacuum horizontal continuous casting Cu–5Fe–0.15Sn alloy

The Cu–5Fe–0.15Sn alloy was prepared using the vacuum horizontal continuous casting method, followed by comprehensive microstructural analysis using optical microscopy (OM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results highlight a significant impact of traction speed on both microstructure and properties. As traction speed increases, there is a notable reduction in the size of primary Fe phases, leading to a more uniform distribution of Fe phases. Initially, hardness experiences an increase followed by a subsequent decrease, while electrical conductivity exhibits an inverse trend. The dendritic and globular Fe phases undergo a transition into Fe fibres following multi-stage deformation heat treatment. Furthermore, the Fe fibres and precipitated Fe phases exhibit smaller, denser, and more uniformly distributed characteristics with increasing traction speed. At a traction speed of 0.15 m/min, the Cu–5Fe–0.15Sn alloy showcases peak tensile strength and electrical conductivity values of 826 MPa and 67% IACS, respectively. These values surpass those attained through other traction processes, indicating superior overall performance of the alloy fabricated at a traction speed of 0.15 m/min.