Understanding the effect produced by combined processing and drawing on the structure and properties of conductive semi-finished products made of Al – Zr alloys

Abstract

The results of experimental studies of the properties of an experimental batch of deformed semi-finished products from alloys of the Al – Zr system, made using the methods of combined processing and drawing, are presented. The influence of combined casting, rolling-extrusion and drawing conditions on the mechanical properties and electrical resistivity of deformed semi-finished products for electrical purposes with different zirconium and iron contents is studied. The rational modes of joint hot and cold machining of the alloys under study have been determined, which make it possible to achieve high strength, ductility and electrical conductivity of conductive semi-finished products. The microstructure of the experimental samples was analyzed with a light microscope, the influence of combined casting and rolling-extruding and cold-drawing modes on the metal flow pattern and phase distribution in the structure of rods and wire was established. Temperature tests of an experimental batch of deformed semifinished products after hot and cold machining were carried out in accordance with the international standard IEC 62004–07. The level of heat resistance of manufactured rods and wire when heated to operating temperatures is set. The regularities of the change in the temporary resistance to rupture and the relative elongation of the test samples after temperature tests are determined depending on the different conditions of combined casting, rolling-pressing and cold drawing. Recommendations on the content of alloys and modes of production of rods and wire with a stable structure during heating and a given level of operational properties of cable and conductive semi-finished products were formulated. Application of the technological scheme using the methods of combined casting, rolling-extruding and drawing allows to obtain the required level of strength properties and heat resistance of semi-finished products from aluminum alloys of the Al – Zr system with different iron content.