The role of two-stage powders mixing and tungsten element on mechanical and electrical properties of the CuNiFe-xW alloys

Cu-based alloys are extensively utilized in engineering applications, including electrodes for electrical components.The combination of both transition and refractory elements is a promising candidate for this application due to their superior ductility and strength at elevated temperatures.This study examines the influence of (W, Fe) pre-milling time and the (x=1, 3, 5, 7) wt.%W element on the characteristics of CuNiFe-xW alloys synthesized by powder metallurgy through a two-stage powder mixing process.The initial stage involved the mixing of (W, Fe) powders through pre-milling utilizing planetary ball milling for durations of 0.5, 1.0, 2.0, and 4.0 h, maintaining a ball to powder ratio (BPR) of 10:1.The second mixing stage entails the mixing of (W, Fe) and (Cu, Ni) powders by using a V-mixer for 120 minutes at low velocity, followed by cold compaction and high-temperature sintering, the characteristics of sintered CuNiFe-xW alloys were assessed through mechanical and electrical tests at ambient temperature.Microstructural analyses, fracture morphologies, and elemental distributions in the sintered model CuNiFe-xW alloys were performed using a scanning electron microscope (SEM) and Energy Dispersive Spectroscopy (EDS) at various magnifications.The crystal structure of CuNiFe-5 wt.%W alloys in both powder and bulk forms was analyzed using the X-ray diffraction method (XRD).Furthermore, the electrical properties of the model CuNiFe-xW alloys were measured using the four-probe measurement method.The findings indicate that the inclusion of W and (W, Fe) pre-milling markedly improves the hardness and compressive yield strength of model CuNiFe-xW alloys.The augmentation of pre-milling durations for (W, Fe) powders diminishes the crystallite size, enhances uniform particle distribution, and elevates electrical conductivity.It is clear that the addition of W and the implementation of (W, Fe) pre-milling positively influence strength; nevertheless, the presence of W tends to reduce the electrical conductivity of the CuNiFe-xW alloys.