Refinement Process and Mechanism of Nano Cu-Ni-Zr Alloy by High-Energy Ball Milling

Nano Cu-Ni-Zr alloys were synthesized using a mixture of Cu, Ni and ZrO2 powders of 350 meshes through high-energy ball milling for 10 to 50 hours. Analysis via scanning electron microscopy (SEM) and X-ray diffraction (XRD) suggests that the particle nanocrystallization process during ball milling can be divided into four stages: welding, squeezing, fracturing, and dynamic equilibrium. Examination of the particle size distribution and element composition of the Cu-Ni-Zr alloy after 50 hours of milling reveals the formation of a nano-polycrystalline structure with an average grain size of 28 nm. Additionally, this process transforms the initial metal mixture into various alloys such as Ni-Zr, Cu-Ni, as well as compounds like CuO and ZrO2. Calorimetry using this alloy in low-energy-nuclear-reaction experiments exhibited excess heat.