Effect of silver nanopowder addition on mechanical properties of silver-copper alloy used in the jewellery industry

Abstract

In this research, silver nanopowder (at rates of 0%, 0.5%, 1%, 1.5% and 2%) was added to 925-carat silver-copper alloy used in manufacturing silver jewellery to increase its durability and to observe its mechanical properties occurred. In this context, different mechanical tests (tensile, bending and hardness) were performed on exclusively produced silver-copper alloys. Moreover, mechanical simulation tests were conducted via ANSYS software using the data obtained from the experimental results. In the tensile tests, it was observed that the use of nanopowder at the rates of 0.5% and 1% positively affected the tensile strength and strain values, while when the nanopowder rate exceeded 1%, both parameters were negatively affected. According to tensile test results, the ductility of the alloy material decreases as the rates of nanopowder addition rise. In the bending tests, it was observed that the addition of 1% nanopowder increased the bending strength significantly; however, other addition rates had a negative effect. Hardness measurements showed that the 1% nanopowder ratio had a much higher effect (in terms of increasing the hardness value) on the hardness value than 0.5%, 1.5% and 2% nanopowder ratios. In order to verify the numerical analysis model, the results of both experimental and numerical analyses were compared. The success of numerical modelling was found to be ∼96% in terms of both tensile strength and displacement. Many methods are used in the jewellery industry, especially in silver jewellery. To easily shape the material to be used in filigree, repousse, and tattoo techniques, the material must be somewhat soft and pliable. Therefore, if production is carried out using these techniques, it is not advisable to add large amounts of nanopowder to the alloy. Furthermore, adding quite low amounts (0.1%, 0.5% etc.) of nanopowder to the silver-copper alloy will provide efficient results in shaping-based production techniques.