Various Manufacturing Technologies and Their Influence on the Fatigue Strength of Cu-Mg Wires

Copper alloys are widely used in many branches of industry due to their excellent corrosion resistance and high level of both electrical conductivity and strength. Among others, there are copper alloys with magnesium, which are known and commonly used with Mg content of up to 0.7 wt.%. Here, we study Cu-Mg alloys with 2.8 wt.% and 3.2 wt.% of Mg, the properties of which are yet to be determined. One of these is the fatigue strength of materials, which is crucial for maintaining the long-term and safe operation of wires in engineering applications. Fatigue is a process during which materials are subjected to cyclic stress below the ultimate tensile strength of materials, leading to their damage or failure. In the current paper, CuMg2.8 and CuMg3.2 wires were obtained using a laboratory chain drawbench and an industrial drum-type drawing machine to verify the influence of manufacturing technology on the fatigue strength of materials. The obtained results were correlated with analogically obtained copper wires by taking into consideration the influence of the chemical composition, structure of fractures, stress and manufacturing technology. It was discovered that it is possible to obtain wires regardless of the drawing machine type and the concentration of Mg. However, CuMg3.2 wires obtained in the industrial conditions experienced delamination and brittle fractures during unwinding from the drum, and thus, their use was not possible.