Preparation and Performance of High Conductivity Heat Resistant Al-Cu-Sc-Zr Alloy.

This paper presents the synthesis and characterization of Al-0.35Cu-0.18Sc-0.06Zr alloys, possessing remarkable electrical and mechanical properties. Specifically, the electrical conductivity and tensile strength of this alloy are reported to reach 60.4%IACS and 169.46 MPa, respectively. The electrical conductivity combined with Wiedemann–Franz law was calculated for Al-0.35Cu-0.18Sc-0.06Zr alloys thermal conductivity as showing excellent thermal conductivity. Microscopic analysis shows that a large number of fine "bean-petal" shaped Al₃(Sc, Zr) particles, i.e., the second phase, were diffusely distributed in the alloy. These particles are highly cohered with the matrix, resulting in small and shallow toughness dimples at the tensile fracture. Due to the low diffusion coefficient of Zr element, the growth rate of precipitated second phase particles can be effectively reduced, which leads to forming Al₃(Sc, Zr) phase with Zr-rich shell and improving the intrinsic coarsening property of Al₃Sc phase. The Al₃(Sc, Zr) second phase exhibits a large surrounding strain of approximately 2.5%, resulting in a significant elastic strain field that inhibits dislocation movement, thereby increasing alloy strength. Furthermore, the heat resistance test results show that the alloy can operate steadily at 503 K for up to 350, 400 h. [ABSTRACT FROM AUTHOR]