First-Principles Study on Solution Strengthening Effect of Cu and Zn in Ag Alloy

A first-principles plane-wave pseudopotential method based on the density functional theory was used to investigate the mechanical properties and electronic properties of AgCu and AgZn solid solution. The VCA models have been set up for solid solution, and elastic constants, bulk modulus and shear modulus, Young modulus and density of states of Cu or Zn doped Ag system were also analysed. The results show that Cu and Zn in Ag alloy play a role of solution strengthening, the solid solution strengthening effect was obviously improved by adding a small amount of Cu(less than 2at.%) or Zn(less than 1at.%). The total DOS of AgCu(Zn) Solid solution is mainly constituted by the Ag 4d and Cu(Zn) 4d states. The AgZn Solid solution has a more stable structure than AgCu solid solution. (paper)