Effect Of Low Temperature Deformation And Heat Treatment On Microstructure And Properties Of 6201 Aluminum Alloy

Protecting the environment and saving resources are the necessary conditions for building a sustainable society.Therefore,the demand for low density,high strength and high conductivity metal materials is increasing day by day.Among them,aluminium alloy has low density and relatively high conductivity,so aluminium alloy has become the preferred material for industrial products.The main alloying elements of 6201 aluminium alloy are magnesium and silicon,and the strengthening phase is Mg2Si.It belongs to heat-treated and strengthened aluminium alloy.Its strength is medium.It has good workmanship and corrosion resistance,no stress corrosion cracking tendency,good welding performance and good extrusion performance.In this paper,the effects of rolling at different temperatures and aging on the mechanical and electrical properties of 6201 aluminum alloy are discussed.The main conclusions are as follows:(1)When 6201 aluminium alloy is rolled after solid solution,the lower the rolling temperature is,the more dislocation cells and dislocation arrays are,and even subcrystals will evolve with the same rolling reduction.When the rolling deformation is 70%,the tensile strength of cooling rolling at-196?,cooling rolling at-70? and rolling at room temperature are 341 MPa,315MPa and 309MPa,respectively.(2)The conductivity of 6201 aluminium alloy increased to 54.5%IACS after cooling-rolling at-196? and aging at 165 ? for 3 hours,which was 7.3%higher than that of cooling-rolling at-196? and aging at 125? for 4 hours(50.8%IACS).However,the tensile strength of 6201 aluminium alloy was only 311MPa,which was 9.8%lower than that of cooling rolling at-196? and aging at 125 ? for 4 hours.(3)After cooling rolling at-196? and aging at 125? for 4 hours,the tensile strength reaches 345MPa,which is 19.2%higher than that of room temperature rolling plus aging at 125? for 4 hours(292MPa).In terms of conductivity,the conductivity of-196? cooling rolling+125? aging for 4h is 50.8%IACS,while that of room temperature rolling+125? aging for 4h is 50.1%IACS.This is because the needle-like beta phase size is larger than that of nano-clusters in GP region,which hinders the movement of electrons.(4)In the aging process of 6201 aluminium alloy after cooling at-196? and rolling at 125?,GP zone is formed in the aging process with lower aging temperature,and dislocation recovery is relatively small,and the strengthening effect of aging occupies a dominant position,resulting in higher strength;the reduction of defects such as vacancies and interstitial atoms and dislocation recovery in the aging process are conducive to the reduction of resistivity and the increase of electrical conductivity.