Study On The Performance Of Al-Mg-Si Conductor

Al-Mg-Si aluminum alloy,which is a heat-treated and reinforced aluminum alloy.is widely used as a conductive material in conductive profiles and large-span overhead transmission lines.In this paper,the self-developed Al-Mg-Si alloy is used as the research object,and its performance changes are analyzed by means of Vickers hardness test,conductivity test,tensile strength test,polarization curve test and salt spray corrosion test.Scanning electron microscopy(SEM)was used to analyze the microstructure changes of the alloy.The effects of heat treatment system,alloy composition and surface treatment on mechanical properties,electrical con ductivity and corrosion performance of the alloy were further explored.The main research results are as follows:(1)The addition of Mg and Si elements to industrial pure aluminum improves the strength of the deformed and annealed matrix but seriously impairs the electrical conductivity of the matrix.However,when Mg and Si elements are added to a certain amount,the alloy exhibits an ageing strengthening effect.After aging treatment,the alloy not only has high electrical conductivity but also has high strength.(2)When the amount of Mg and Si added is low,it is necessary to increase the aging temperature to produce a significant age hardening effect.Lowering the solution temperature and reducing the solution time can further improve the strength of the alloy.(3)In the Si excess Al-Mg-Si alloy,Mg/Si is close to 1.1,which is beneficial to the best performance of the alloy.When the electrical conductivity of the alloy is greater than 60.2%IACS,the tensile strength is still higher than 135 MPa.The increase in Mg content facilitates accelerated aging and improves the tensile strength and aging stability of the alloy.The increase of Si content can promote the precipitation of aging,which has a certain hindrance to the improvement of conductivity.(4)Through the oxidation sealing experiment,the corrosion resistance of the Al-Mg-Si aluminum alloy used in the experiment is improved obviously:the corrosion potential is positively shifted,the corrosion current is reduced,and the corrosion tendency is weakened;the peak-aged aluminum alloy is not suitable for copper and iron.Contact use;copper sulfate titration time is greatly prolonged,indicating that the oxide film is dense and uniform,in the salt spray corrosive environment,subjected to 100h corrosion,basically no significant change.