Quantitative mechanisms behind the high strength and electrical conductivity of Cu-Te alloy manufactured by continuous extrusion

The microstructure, mechanical performance, and electrical conductivity of Cu-Te alloy fabricated by continuous extrusion were quantitatively investigated. The results demonstrate that the grain size of the Cu-Te alloy is refined significantly by incomplete dynamic recrystallization. The Cu2Te phase stimulates recrystallization and inhibits subgrain growth. After extrusion, the tensile strength increases from 217.8 ± 4.8 MPa to 242.5 ± 3.7 MPa, the yield strength increases from 65.1 ± 3.5 MPa to 104.3 ± 3.8 MPa, and the yield to tensile strength ratio is improved from 0.293 ± 0.015 to 0.43 ±.0.091, while the electrical conductivity of room temperature decreases from 95.8 ± 0.38% International Annealed Cu Standard (IACS) to 94.0% ± 0.32% IACS. The quantitative analysis shows that the increment caused by dislocation strengthening and boundary strengthening account for 84.6% of the yield strength of the extruded Cu-Te alloy and the electrical resistivity induced by grain boundaries and dislocations accounts for 1.6% of the electrical resistivity of the extruded Cu-Te alloy. Dislocations and boundaries contribute greatly to the increase of yield strength, but less to the increase of electrical resistivity.