The Microstructures And Properties Of Al-Zr-B-Y Heatresistant Aluminum Alloy Wires Prepared By Continuous ECAE Aging Forming

Aluminum has small density, high specific strength, better electrical conductivity and heat-conducting property. High temperature heat resistant aluminum alloy wire is a new kind of special wires. Compared with traditional wire, it has high temperature strength, has a good ability to resist freeze disaster. According to the production–research status of Al-Zr-B-Y resistant heat electric conductors, Al-Zr-B-Y alloy electric conductive wire was studied object in this paper, through the DEFORM-3D simulation, optimization to improve mold structure, make it more reasonable; using continuous ECAE dynamic aging molding process to improve the comprehensive mechanical properties and electrical conductivity of aluminum alloy conductor. Through dynamic continuous extrusion ECAE process, to determine the optimum extrusion times; through the aging treatment, further improve the comprehensive performance of conductor. By means of metallographic microscope, aging treatment furnace, scanning electron microscope(SEM), the tensile testing machine and equipment, including arms dc bridge instrument study continuous dynamic aging ECAE processing of Al-0.3Zr-0.06B-0.2Y alloy microstructure, mechanical properties and electric conductivity. The main results are as follows:(1) By using Deform-3D software simulation,Optimization of ECAE mould and simulation of drawing process. the temperature of aluminum wires increases with the increase of drawing passes, drawing speed and friction coefficient. The temperature of the finished drawing wires without cooling is above 180℃ in drawing process, the influence of friction on temperature of wires is larger than that of drawing speed.(2) Compared to traditional technology, the continuous ECAE process preparation of aluminum alloy, grain refining, alloy performance is more superior, mechanical properties and electrical conductivity has a qualitative improvement. In this paper, using 99.7% pure aluminum ingots as raw material, when the content of rare earth element Y was 0.2% in Al-0.3 Zr-0.06 B-Y alloy, process parameters are as follows: Pouring temperature is 350 ℃, ECAE extrusion temperature is 750 ℃, the ways of extrusion are 4, dynamic continuous ECAE forming Al-0.3 Zr-0.06 B-0.2Y alloy rod has excellent mechanical properties and electrical conductivity. Their equivalent conductivity、corresponding tensile strength and elongation, is 59.5%IACS 、249.3MPa and 11.3% respectively.(3) With the increase of content of Y elements, the grains of Al-0.3Zr-0.06 B alloy can be refined. When the content of Y elements is 0.2%, grain degree of homogenization is best. In the process of Al-0.3Zr-0.06 B alloy solidification, only a small amount of supersaturated solid Y elements dissolved in alloy, most of the partial in the grain boundary in place. After adding Y element their equivalent conductivity、corresponding tensile strength and heat resistance all enhance.And that the equivalent conductivity is the highest with the 0.2% Y in the Al-0.3Zr-0.06 B alloy which it is59.5%IACS.(4) Under the condition of over aging, the equivalent conductivity of Al-Zr-B-Y alloy is best,It has a high strength and best combined properties.Al-0.3Zr-0.06B-0.2Y alloy at over aging with the temperature、time、corresponding tensile strength、elongation and equivalent conductivity is ① 160 ℃、 12 h 、 267.76 MPa 、 7.0% 、59.32%IACS,②180℃、12h、265.32MPa、6.7%、59.54%IACS,③200℃、12h、263.21MPa、6.4%、59.73%IACS,④220℃、12h、261.87MPa、6.2%、59.94%IACS。(5) Adding Y element improved electric conductivities of Al-0.3Zr-0.06 B significantly. Electric conductivities reach peak in the aging 16 h, that Al-0.3Zr-0.06B-0.2Y is 59.4%IACS。...