Study of the Influence of Conditions of Combined Casting and Rolling-Extruding and Two-Stage Annealing on the Structure and Properties of Semi-Finished Electrical Products from an Al–Zr System Alloy

Abstract

This article presents the results of the study of the joint effect of the processing conditions of the new composition of the Al-Zr system alloy by combined casting and rolling-extruding and two-stage annealing on the structure and properties of round bars used in the manufacture of heat-resistant wires. The research show patterns of changes in the properties, the specific electrical resistance of the bars, depending on different conditions of deformation and heat treatment of aluminum alloy with a content of 0.3% zirconium and 0.2% iron. The results of micro-X-ray spectral analysis and the granular structure of the samples before and after two-stage annealing confirming the stability of the structure after heating and preserving the strength of semi-finished products. Presented parameters of combined casting and rolling-extruding and two-stage annealing for the manufacture of rods from the studied alloy make it possible obtaining good combination of mechanical properties and electrical conductivity.

Development of Combined Machining Modes, Investigation of Mechanical Properties and Structure of Deformed Semi-Finished Products from Alloy 01417

“…The next stage was the study of the microstructure of deformed semi-finished products in the form of rods after CRE and rods and wire during passes (Table 2) and wire with Ø0.5 mm after drawing and bar rolling with drawing after heat treatment (Table 3). Previous studies [16][17][18][19][20][21][22] made it possible to determine that the wire obtained by the method using bar rolling and subsequent drawing, after annealing according to the temperatures 350, 400, 450 °C modes and holding time of 1 h, has the required level of properties in accordance with TS 1-809-1038-2018. Annealing the wire according to the regime with a temperature of 500 °C and a holding time of 1 h leads to a decrease in the ultimate tensile strength to 137 MPa, which does not correspond to TS 1-809-1038-2018, but elongation to failure (19.1%) allows further machining of the ingot to diameters of the order of 0.1-0.2 mm, if it is necessary to obtain such a wire.…”

“…To test the studied deformation modes, experimental studies were carried out on the CRE-200 installation, manufactured on the basis of the DUO 200 rolling mill according to the previously developed methodology [10,12,16,17,19,22]. The general technological scheme for producing wire is presented in Fig.…”

“…2. The mechanical properties were determined using the following equipment: Walter + Bai AG universal electromechanical testing machines LFM 400 kN for rods and LFM 20 kN for wires ("Walter + Bai AG", Switzerland) in accordance with State standard 1497-84 for rods and State standard 10446-80 for wire [10,12,16,17,19,22]. Electrical resistivity ρ was measured on samples 1 m long using a "Vitok" ohmmeter in accordance with State standard 7229-76.…”

Simulation of Ingotless Rolling-Extruding of Rods from Alloy of Al-Zr System and Investigating into their Properties

“…Fig. 1 Computer model of the combined processing unit CRE-200 [3,4,16] The geometrical parameters of the roll tool with the roll diameters along the protrusion D 1 = 214 mm and the bottom of the caliber D 2 = 167 mm, the width of the caliber b = 14 mm, the minimum height of the caliber on the common axis of the rolls h 1 = 7 mm; the height of the die mirror h 2 = 20 mm and the diameter of the calibrating hole of the die d = 5, 7 and 9 mm. The technological parameters were as follows: the temperature of the melt before pouring into the rolls was 800 °C; roll temperature 100 °C; roll rotation speed 4 rpm; the degree of deformation during rolling 50%; the extrusion coefficient during pressing was 4.4, 7.3, and 14.3 (the diameter of the rods was d = 9, 7, and 5 mm, respectively).…”

“…Recently, simultaneously with the growing demand for aluminum conductor products, the requirements for the quality of semi-finished products for its manufacture have been increasing. First of all, modern electrical engineering requires long rods of round cross section with a plasticity level that provides the possibility of subsequent cold processing without destruction, minimum weight, electrical resistance and strength level, which remains after heating the wires to 200 ºС [1][2][3].…”