The Microstructures And Properties Of Al-Zr-B-(La.Ce) Heat-resistant Aluminum Alloy Wires Prepared By Continuous Dynamic Aging Ecae Forming

Al-Zr-B-(La, Ce) heat-resistant alloy, as a kind of overhead wires, is widely used in areas of frost disasters and harsh natural environment due to its good mechanical,heat-resistant and conductivity performance. At present, the traditional Al-Zr-B-(La, Ce)heat-resistant alloy process is relatively unitary. The performance improvement of the wires is limited and the domestic researches and applications are relative underperformance. In order to open up a new way for preparing high performance aluminum heat resistant alloy wires in our country, the microstructure and properties of Al-Zr-B-(La、Ce)alloy produced by continuous dynamic aging Equal Channel Angular Extrusion(ECAE) process is studied in detail in this paper. This work is financially supported by the National Natural Science Foundation of China(NO.51174139).The continuous dynamic aging ECAE, cold-draw and artificial aging processes and theory for Al-Zr-B-(La、Ce) alloy were researched by Deform-3D simulation technology,OLYMPUS-BX51 M metallographic microscope, traditional SEM and X-ray spectrometer technology as well as the tensile testing machine in this paper. The main results were described as follows:The results of finite element simulation show that the alloy wires temperature mainly varied with the tensile rate and friction coefficient. The deformation temperature of the wire rose with the increase of the drawing speed and friction coefficient.Moreover, the friction coefficient had the larger effect on the deformation temperature;The continuous dynamic aging ECAE process for producing Al-Zr-B-(La, Ce)heat-resistant alloy conductor was optimized as: the 280℃ ECAE temperature and the BC ECAE path. The equivalent electrical conductivity was 56.53% IACS and tensile strength of samples was 256.37 MPa, respectively. The continuous dynamic aging ECAE forming process was beneficial to improve the comprehensive performance ofthe alloy conductor;The evolution microstructure of the alloy conductor was analyzed: the microstructure of Al-Zr-B-(La, Ce) alloy was uniformed and refined with the increase of the ECAE passes. The fine equiaxed grains that were formed in the fourth pass could be conducive to improving the properties of the alloy;The effects of aging process on the properties of Al-Zr-B-(La, Ce) heat-resistant conductor were also studied in this paper. The electrical conductivity of the alloy could be effectively improved by rational over-aging treatment. Considering scheme synthetically, the optimum heat treatment was determined as 200 ℃ furnace temperature for 10~12h. During aging process, the tensile strength and elongation were290.05~288.72 MPa and 6.9~6.5%, respectively. Meantime, the equivalent conductivity was 60.40~60.63%IACS. In contrast, the comprehensive performance of the wires prepared by continuous dynamic aging ECAE process was greatly improved.