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ID:32190114
大小:5.83 MB
页数:62页
时间:2019-02-01
《纳米晶镁合金表面化学镀ni-p合金镀层的分析》由会员上传分享,免费在线阅读,更多相关内容在学术论文-天天文库。
1、太原理工大学硕士研究生学位论文resistanceofNi—Pcoating.Thethesisfocusedontheoptimumprocesstoobtainthefavourablecoatingofmorphology,uniformthickness,wearandcorrosionresistanceproperties.Tilematrixgrainweretessellatedanddefectswerereduced,SOthatthequalitywasenhancedandcorrosionresistaneeofNi—Pc
2、oatingonmagnesiumalloycouldbeimprovedthroughnano—processonthesurfaceofmagnesiumalloy.Inaddition,thepaperstudiedtheinfluenceofthermaltreatmentontheNi—PcoatingofNanocrystallinemagnesiumalloy.Basedonthestudies,themainconclusioncanbedrownasfollows:1、Theoptimaltechnologicalschemeof
3、electrolessplatingwhichwascheapandsimplewasconfirmedfrommultipleexperiments.NiS04’6H20NaH2P02’H20CH3COONaNH4HFHF(40%)thiocarbamidePH16g/L;14g/L;13g/L;8g/L;12ml/L;0.001g/L;6.4±O.2:Temperature:80±2℃。2、Thr。ughthisl(i11d。ftecllll。1。giJIllscheme,thetypicalcellularstructurecouldbeob
4、tainedwithcompactanduniformcoatingbutnoobviousdefect(averagein20—30Ⅲm)Ni—Pplatingwasphosphoruscoatingwithphosphorus。V】太原理工大学硕士研究生学位论文contentwasbetween5%and8%.3、Comparedtothecoarse—grainedmagnesiumalloy,theplatingrateonnanocrystallinewasslowerinmagnesiumalloysurfaceelectrolessp
5、latingwhichwastreatedbymeansofnano.Thereasonwasthatnanocrystallinemagnesiumalloyownthebiggerspecificsurfaceareaandencounteredmoreresistanceinstageofsurfacenucleation.Whereasinthenucleationstage,theactivationpointandplatingrateofnanocrystallinemagnesiumalloygotmore,coatingthick
6、nesswasalsogreat.4、ThehardnessoftheNi—Pcoatingonthesurfaceofmagnesiumalloywasreachedto427HVwhereasthecoatingonthenanocrystallinecouldbeattainedto689HVBymeansofthermaltreatment.thehardnessofthecoatingwaspromotedfurtheron.Especiallywhenthetemperaturewas300。C,itcouldbereachedto13
7、0HV.Thewear—resistingperformanceofthecoatingcouldbepromotedthroughthehardness.Moreover,thefrictioncoefficientisdecreaseslightly.5、Thecorrosionresistanceofmagnesiumalloycouldbereducedbynanocrystalline,butitonNi—Pcoatingwasincreased.Thecorrosionresistanceofcoatingdepressedaftert
8、hermaltreatment.Meanwhile,itgotworseandworseinthewakeoftemper
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