镁合金化学镀镍溶液稳定性VIP免费

第60卷第3期化工学报Vol160No132009年3月CIESCJournalMarch2009研究论文镁合金化学镀镍溶液稳定性胡波年1,2,李亭憬1,余刚1,张俊1,吴振军1,何晓梅2(1湖南大学化学化工学院,化学生物传感与计量学国家重点实验室,湖南长沙410082;2湖南工学院化学化工系,湖南衡阳421008)摘要:为了开发出长寿命高稳定性镁合金化学镀镍溶液,通过添加硫脲、碘酸钾等稳定剂,研究了pH值、温度对镀液的稳定性能、镀速、镀层质量等因素的影响。采用称重法测定镀层的沉积速率,沉积到镀件上的镍量占溶液中消耗镍量的百分比来表示溶液的稳定性,NaCl溶液浸泡实验评定镀层的覆盖度,热震实验评定镀层的结合力,极化曲线表征镀层的耐蚀性。结果表明,沉积速率随硫脲、碘酸钾浓度的增大先升高后降低,碘酸钾对镀速的影响不如硫脲显著。添加硫脲015mg·dm-3时稳定常数最大值达89125%,添加碘酸钾5mg·dm-3时,稳定常数达82145%。采用pH值为510的含硫脲的镀液,(82±1)℃施镀,获得的Ni2P镀层和镁合金基体之间没有缝隙,结合紧密,而且Ni2P镀层均匀致密。硫脲不仅能提高沉积速率,而且也催化镁合金表面,提高沉积效率。关键词:镁合金;化学镀镍;稳定性;硫脲;碘酸钾中图分类号:TQ153114文献标识码:A文章编号:0438-1157(2009)03-0696-06BathstabilityofelectrolessplatingnickelonmagnesiumalloysHUBonian1,2,LITingjing1,YUGang1,ZHANGJun1,WUZhenjun1,HEXiaomei2(1StateKeyLaboratoryofChemo/BiosensingandChemometrics,SchoolofChemistryandChemicalEngineering,HunanUniversity,Changsha410082,Hunan,China;2DepartmentofChemistryandChemicalEngineering,HunanInstituteofTechnology,Hengyang421008,Hunan,China)Abstract:Themainpurposeoftheresearchwastodevelopanelectrolessnickelbathwithlongcyclesandhighstability1Thioureaandpotassiumiodatewereaddedintheelectrolessbathasthestabilizingagents1TheeffectsoftemperatureandpHvaluesonthebathstability,platingrateandcoatingqualitywerestudied1Weighingwasusedtomeasurethedepositionrateofcoating1Thestabilityofthebathwascharacterizedbypercentageofthenickelonthesurfaceofworkpiecetototalnickelconsumptioninthebath1ThecoverageofcoatingwasevaluatedbyimmersiontestinNaClsolution1Theadhesionofcoatingwasevaluatedbythermalshocktest1Polarizationcurveswereusedtocharacterizethecorrosionresistanceofcoating1Theresultsshowedthatthedepositionrateincreasedatfirst,thenwentdownwithincreasingconcentrationofthioureaorpotassiumiodate1Thedepositionratewasmoresignificantlyaffectedbythioureathanthatbypotassiumiodate1Themaximumvalueofstabilityconstantreached89125%inthebathof015mg·dm-3thioureaandthestabilityconstantwas82145%inthebathof5mg·dm-3potassiumiodate1Whenplatingwascarriedoutat(82±1)℃inthepH510bathof015mg·dm-3thiourea,uniformanddensecoatingwasobtained,andtherewasnogapbetweenNi2PcoatingandMgsubstrate1Thioureanotonlyimprovedthedepositionrate,butalsocatalyzedthesurfaceofmagnesiumalloyandraisedthedepositionefficiency1Keywords:magnesiumalloys;electrolessnickelplating;bathstability;thiourea;potassiumiodate2008-10-31收到初稿,2008-12-15收到修改稿。联系人:余刚。第一作者:胡波年(1957—),男,教授。基金项目:国家自然科学基金项目(50671036);湖南省科技项目(06JJ4013,2008FJ3117)。Receiveddate:2008-10-31.Correspondingauthor:Prof.YUGang.E-mail:yuganghnu@1631comFoundationitem:supportedbytheNationalNaturalScienceFoundationofChina(50671036).©1994-2010ChinaAcademicJournalElectronicPublishingHouse.Allrightsreserved.http://www.cnki.net引言在镁合金上进行化学镀Ni2P处理,不仅可以获得高的耐蚀性和耐磨性,而且能够在形状复杂的铸件上得到厚度均匀的镀层。但是,由于化学镀Ni2P镀液是一个热力学不稳定体系,工业化的镍磷沉积镀液中常有不可避免的胶粒和固体微粒存在。这些微粒因...