Исследование термической стабильности структуры и механических свойств композитной проволоки из алюминиевых сплавов Al – 0,25 % Zr – 0,1 % (Sc,Hf)

Abstract

The thermal stability of a bimetallic wire made of four novel aluminum alloys Al – 0.25 % Zr with different Sc and Hf contents has been investigated. A wire made of pure aluminum A99 was studied as an object of comparison. Alloys were obtained by injection molding in vacuum. Cast samples were subjected to severe plastic deformation and annealing, which ensured the formation of a uniform microstructure and the release of stabilizing Al3(Zr,Sc,Hf) nanoparticles. The wire ∅ 0.26 mm was obtained by joint deformation of an aluminum alloy with a copper shell by rolling in rolls. The effect of 30-minute annealing in the temperature range from 200 to 500 °C on the parameters of the microstructure and physical and mechanical properties (microhardness, strength, plasticity, specific electrical resistivity) of the wire was studied. The wire has high strength and increased thermal stability. After annealing at a temperature of 500 °C, a homogeneous fine-grained structure with a grain size of 3 – 5 µm was formed in the wire, increased hardness and strength of the samples was observed due to the separation of Al3(Zr,Sc,Hf) particles. There is an intense diffusion of copper from the shell into the surface layers of the aluminum alloy, which can lead to embrittlement of the wire.