Microstructural evolution and properties of Cu–20 wt% Ag alloy wire by multi-pass continuous drawing

Abstract

The Cu–20 wt% Ag alloy wire rod was prepared using three-chamber vacuum cold mold vertical continuous up-casting followed by multi-pass continuous drawing. The evolution of microstructure, mechanical property, and electrical property of the Cu–20 wt% Ag alloy wire during multi-pass continuous drawing was studied. After multi-pass continuous drawing, the continuous network eutectic structure in the longitudinal section of the as-casted rod was gradually drawn into long fibers that approximately parallel to the axial direction, while the space of the continuous network eutectic structure in the transverse section is getting smaller and smaller. Both the preferred orientation of copper and silver grains are (1,1,1). With the increase of drawing strain (η), the tensile strength of Cu–20 wt% Ag alloy wire gradually increases while the elongation gradually decreases. When the diameter is drawn to 0.02 mm (η = 11.94), the tensile strength of the alloy is 1,682 MPa and elongation is 2.0%. The relationship between tensile strength, elongation, and diameter conforms to Allometric and Boltzmann functions, respectively.

Keywords

• cu–ag alloy
• multi-pass continuous drawing
• microstructure evolution
• mechanical property
• electrical property