Structure, Strength and Conductive Properties of Vacuum Cu-Ta Condensates CuTa

Abstract

Structure, strength and electrical conductivity of Cu-Ta vacuum condensates with a tantalum concentration from 0.1 to 3 at % is studied. Depending on the content of tantalum, the condensates have different structural states: one-and two-phase, supersaturated tantalum solution in FCC copper lattice. Alloying of copper condensates with tantalum reduces the grain size from ~ 3 m to ~ 50 nm. The optimum ratio of strength properties and electrical conductivity is realized at a tantalum content of ~ 0.4-0.5 at. %. In this case, the ultimate tensile strength reaches ~ 1000 MPa with an electrical conductivity of ~ 50 % of the single-component copper. It is shown that the main contribution to the increase in strength is made by grain boundary strengthening due to the decrease in the grain size and the increase in the Hall-Petch constant.