Study On The Effect Of Solution Treatment On Wear Properties Of 7055 Aluminum Alloy

As a high-strength aluminum alloy,7055 aluminum alloy is used more and more in aerospace,marine,automotive and other fields.In order to reduce the wear and failure of the alloy,the research on the wear performance of 7055 aluminum alloy is particularly important.In this paper,7055 aluminum alloy is taken as the research object.Firstly,in order to improve the properties of the alloy,different solid solution and aging heat treatments are carried out.Secondly,the microstructure and mechanical properties of the treated alloy were tested.Then the friction and wear properties of 7055 aluminum alloy were studied.Finally,the corrosion and wear resistance of the alloy was studied.?Firstly,the mechanical properties of the alloy were observed.The hardness of the water-cooled sample after the alloy was treated by 240 ? × 2h+480 ? × 2h and450? ×1h+480? ×1h was high,reaching 166 HV.The hardness of the rolled sheetafter heat treatment was improved.Among them,the two-stage solution treatment has the highest hardness.It can be seen from the contact angle of the surface of the rolled sheet that the surface of the alloy is hydrophobic after heat treatment,and the hydrophilicity is not heat treated,wherein the contact angle of the240 ? × 2h+480 ? × 2h solution treatment sample is 97°,which has the besthydrophobicity.The metallographic structure of the alloy can reflect that after the heat treatment,the coarse second phase and the fine precipitated phase of the alloy are greatly reduced,and the crystal grains become large and uniform.?Secondly,the friction and wear properties of the 7055 aluminum alloy were tested.As the abrasive grains of the sandpaper became finer,the roughness value of the sample gradually decreased.The friction coefficient and the surface roughness show a nonlinear relationship,and the friction coefficient obtained under the treatment of1200# sandpaper is the smallest.Observing the two-dimensional wear scar morphology of the alloy,it is found that the alloy has a shallow wear mark,a narrow width and a minimum wear after the 240 ? × 2h+480 ? × 2h solution treatment.Compared with dry friction conditions,it was found that under wet conditions,it is beneficial to reduce the wear of the alloy.In dry friction,the alloy has a large amount of abrasive wear,adhesive wear and fatigue wear,while under wet conditions,it ismainly abrasive wear and adhesive wear.?Then,the 7055 aluminum alloy was subjected to electrochemical corrosion test,and the alloy samples of different solution treatments were tested for corrosion resistance in 3.5% Na Cl solution by electrochemical workstation.From the polarization curve analysis,the alloy is positively shifted from the corrosion potential,the corrosion current density is reduced,and the corrosion resistance is improved after the solution treatment.Analysis of the AC impedance spectrum shows that the alloy has a large diameter of the anti-arc after the solution treatment,and the diameter is larger after the450? ×1h+480? ×1h solution treatment.At the same time,the modulus and phaseangle diagrams in the Bode diagram obtained from the test were analyzed,and it was found that the corrosion resistance of the samples after the solution treatment was improved.The data obtained from the electrochemical corrosion test can reflect the static corrosion properties of the alloy.?Finally,corrosion wear test was carried out on 7055 aluminum alloy,and the electrokinetic polarization and open circuit potential test were studied.It was found that the friction coefficient did not change much after heat treatment,but the self-corrosion potential shifted positively and the corrosion current density decreased.From the tests of cathodic protection and anodic acceleration and the influence of applied potential on samples,it was found that the cathode potential inhibited the corrosion,while the anode potential accelerated the corrosion of the alloy.At the same time,with the increase of potential,the corrosion resistance of the alloy decreased and the wear rate increased.The wear morphology of the alloy at different potential was studied,and it was found that the corrosion wear mechanism of the alloy at lower loading potential was mainly abrasive wear.At higher potential,the corrosion wear mechanism of the alloy is mainly adhesive wear and friction-induced corrosion wear.