| In this paper, the preparation technology and microstructure properties of Al-Mg-Si alloy conductor was researched and discussed, in order to mostly improve the mechanical properties of the electrical wires, and at the same time reduce the loss of conductivity, and prepare the new aluminum alloy conductive material to replace copper wire and steel core aluminum stranded wire,so as to reduce cost and save energy. Based on the factory production high purity aluminum, the new Al-Mg-Si alloy was designed for research. Through the design of alloy composition, optimize the process scheme, use high deformation to press aluminum rod, microalloying and aging treatment, properties of Al-Mg-Si alloy was analysised and the microstructure was observed under different conditions, ultimately the optimize material of Al-Mg-Si alloy was obtained.Experimental results showed that with the composition of 0.3wt.%Si, 0.4wt.%Mg,0.12 wt.%Fe, RE and B purification process, cooperated with argon refine, solution treatment(500℃×1h, air cooled), and then extruding(extrusion temperature was 350℃, extrusion speed was3-4mm/s, air cooled), then aging treatment(aging temperature 190℃, holding 8 hours). Finally acquired the wire with conductivity of 62%IACS, tensile strength of 224 MPa, and the comprehensive properties higher than the current level of public reported.Research founded the appropriate aging process was crucial to the Al-Mg-Si alloy after solution and extrusion treatment, and with the Mg2 Si phases dispersed along with the aging treatment the Si content in the supersaturated solid solution was reduced, and as a result the mechanical properties and conductivity was improved. The conductivity of Al-Mg-Si alloy can be increased more than 2% with appropriate aging parameter. In addition, the study also found that with the addition of other alloying elements can further improve the tensile strength of Al-Mg-Si alloy, but had a certain weaken effect on conductivity. Among them, addition of trace Cu can accelerate the β" phase dispersion precipitation process, and got a smaller size, made the aging peak enhancement, ahead of time, but lower conductivity. The peak tensile strength reached to 234 MPa with 0.06 wt.%Cu addition, and the conductivity reduced to 57.7%IACS. With trace Zn, Mn element added, the tensile strength of the alloy was significantly improved, but the electric conductivity was also reduced, the tensile strength reached to 242.5MPa with 0.5wt.% Zn addition,but conductivity dropped to 57.8%IACS. The OM, EDS, and XRD analysis showed the long stripe(Al, Fe, Si, Mg) phase precipitate turned into short-rod with the content of Mn increased, and the smaller size was acquired. This changes made the tensile strength improved, and at the same time had the repaired effect to conductivity.In conclusion, mcroalloying of Al-Mg-Si alloy had a good effect to tensile strength, but considered the conductivity of the alloy it should be added selectively, and cooperated proper aging treatment process to achieve the alloy material and preparation technology with the higher comprehensive properties. |
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