Effect of Heat Treatment on the Structure and Properties of Silver-Coated Copper Powder

Silver-coated copper powder, a cost-effective alternative to pure silver, has gained attention for its potential applications in electronics, energy, and catalysis. To explore the impact of heat treatment on its properties, a series of experiments were conducted with temperature increments of 50 ∘C and varying holding times. The silver-coated copper powder was prepared through chemical plating and was heat-treated to assess changes in surface morphology, conductivity, density, and antioxidant performance. Results show that heat treatment significantly improved surface flatness and smoothness, particularly at 600 ∘C for 5 min followed by 700 ∘C for 10 min. After treatment, the specific surface area decreased from 0.2282 m2/g to 0.2217 m2/g, while bulk density increased from 2.813 g/cm3 to 2.945 g/cm3, improving fluidity and stability. However, dislocation defects and the elimination of surface plasmon coupling between silver particles reduced conductivity, with resistance rising from 2.8 mΩ to 3.2 mΩ. X-ray diffraction showed an increase in silver grain size from 13.68 nm to 20.33 nm, enhancing density but increasing electron scattering. Heat treatment also raised the initial oxidation temperature from 200 ∘C to 230 ∘C but accelerated subsequent oxidation. This study improves upon existing technology by significantly enhancing the surface smoothness, oxidation resistance, density, and specific surface area of the silver-coated copper powder.