铝锂合金微弧氧化陶瓷膜层特性的研究 .pdf
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铝锂合金微弧氧化陶瓷膜层特性的研究--第1页
2007年3月电镀与环保第27卷第2期(总第154期)・25・
铝锂合金微弧氧化陶瓷膜层特性的研究
PropertiesResearchofCeramicCoating0n-LiAlloybyMicro-arcOxidation
刘一洋。赵志龙,阎光明,侯军占
(西北工业大学机电学院,陕西西安710072)
LIUYi.yang,ZHAOZhi-long,YANGuang-ming,HOUJim-zhan
(SchoolofMechanicalElectronicEngineering,NorthwesternPolytechnicalUniversity,Xi’all710072,China)
摘要:采用先恒流、后恒压的微弧氧化方法,在铝锂合金(添加微量稀土元素Ce)表面制备陶瓷化膜层。研究了氧化时闻和
脉冲频率对膜层生长过程和表面形貌的影响。结果表明:膜层厚度随着反应时间的延长而增加,在更高频率的高能脉冲作用
下(>6OOHz)生长速率更快;膜层表面多孔、起伏不平,延长反应时间或提高脉冲频率会导致烧蚀留下的坑洞变大,表面粗糙
度亦随之增大;膜层与基体结合良好,由内部致密层和外部疏松层组成,总厚度可达50;EDS分析表明,膜层由A1、O、Si构
成,sj元素的摄入认为是NaOH—Na2Si03电解液体系中的si一参与反应进入膜层。
关键词:2090铝锂合金;微弧氧化;高能脉冲;膜层生长
Abstract:Aceramiccoatingispreparedbymicro—arcoxidationinacontrolledmodeofconstant—current-earlier-constant-voltage—lateronA1一
LialloyinanelectrolytecontainingNaOHandNa2SiO3.Thegrowthprocessandmicrostructurevariationofmicro—arcoxidationcoatingare
investigated.I1leresultsshowthatthethicknessofcoatingisgrowingwhilethegrowthrateisgraduallydecreasingduringtheprocess.I1le
coatinggrowsmorerapidlyunderhigherfrequency(>6OOHz)byDCpulse.ThethicknessofhteMAOfilmisabout50ttmandhtecoatingis
porousanduneven.ThefabricatedceramiccoatingiscombinedweltlotheA1substrate.Theresultsalsoshowthatceramiccoatingiscomposed
oftwo-layerstructurewihtouterloosezoneandinnercompactzone.ThecoatingismainlymadeofA1,OandSi.TheexistenceofSiimpliesthat
theelementalcomponentinanelectrolyteiscompoundedintothecoatingbyMAO.
Keywords:2090Al_Lialloy;micro-arcoxidation;high—energypulse;coatinggrowth
中图分类号:TG174.45