鋁合金微弧氧化膜的制備工藝及性能優(yōu)化.pdf

1、華南理工大學碩士學位論文鋁合金微弧氧化膜的制備工藝及性能優(yōu)化姓名：龐德林申請學位級別：碩士專業(yè)：材料加工工程指導教師：李文芳袁鎮(zhèn)海20041213華南理工大學碩士學位論文AbstractAnewhybridsolutionsystemofmicroarcoxidizationforaluminumalloywasdevelopedinthispaperbasedontraditionalsole(NaP03)6andNa2SiO3asw

2、ellasK2C03solution.ThecoatingthicknessdroppingtestandcorrosionresistanceinNaClsolutionwereinvestigatedandthenoptimalelectrolyteconcentrationswereobtainedbyorthogonalexperimentaltest.Furthermoretheeffectofcurrentdensityan

3、doxidizingtimeongrowthandpropertiesofaluminumalloymicroarcoxidizationceramiccoatingwerestudiedandthenoptimalprocessparameterswereobtained.ThemorphologyandmicrostructureofthecoatingwereobservedthroughSEMandXRDtechniques.T

4、heresearchresultsshowthat:ThecoatingthicknessandcorrosionresistanceinNaClsolutionincreaseswiththeincreaseof(NaPO3)6Na2SiO3K2CO3concentrations.Howeverthereexistsoptimalvaluesof(NaP03)6、Na2SiO3、K2CO3concentrationswhichinfl

5、uencedroppingcorrosionresistanceofthecoating.Theoptimalsolutionsystembasedonaboveresearchresultsnamely(NaP03)6:15gLNa2Si03:lOgLK2COV5gLandNa2EDTA:4g幾.Thereexistsoptimalvaluesofcurrentdensityandoxidizingtimewhichinfluence

6、droppingcorrosionresistanceofthecoatingnamely20Adm2and1520minutes.HowevercorrosionresistanceinNaClsolutionofthecoatingincreaseswiththeincreaseofcurrentdensityandoxidizingtime.Thecorrosionresistanceofdroppingtestandimmers

7、inginNaClsolutionofthecoatingoxidizedbyoptimaloptimalsolutionsystemandprocessparametersimprovebyeightytimesand3.4timesthanaluminumalloyrespectively.Themicroarcoxidizationcoatingprocessesexcellentcorrosionresistance.Theco

8、atingiscomposedofcrystalandnoncrystalA1203phase.ThecontentnoncrystalA1203phaseincoatingincreaseswiththeincreasesofcurrentdensityandoxidizingtime.Thecoatingconsistsoftwolayerslooselayerandcompactlayer.Thelooselayerhavemic