ses，anditisprofitableforni-w-pcoatingtodepositinthecathode，formingni-w-p-sicandre-ni-w-p-siccomposites.onthecontrary，theadditionofptfeinthebathdecreasescathodicdepositingcurrentdeityofthecoatings.thecurrentdeityincreasesalittlewhentheamountofrareearth（re）is7~9g/l；however，thedeityincreasesgreatlywithincreasingamountofre，anditreachespeakvaluewhentheamountofreis11~13g/l.butiftheamountofreisraisedfurther，thecurrentdeitydecreases.mechanismofsicparticlesandni-w-pcoatingco-depositionis:sicparticlescarryaboutnegativeelectricchargeitself,andtheymayadsorbpositiveelectricchargearoundwhensicparticlesareaddedinthebath.theymovetothesurfaceofcathodeandformweakadsorptionundertheeffectsoffluiddynamicsandelectricfieldforce;secondly,sicparticlesonthecathodicsurfacedehydrateundertheeffectoftheelectrostaticfieldforceandformstrongadsorptiothirdly,sicparticlesadsorbedonthecathodicsurfacearecapturedbyni-w-pcoatinganddepositedinthecomposite.
corrosionexperimentsofre-ni-w-p-siccompositecoatinginh2so4，hcl，h3po4andfecl3solutioshowthatthecompositecoatingsonthebaseofni-w-pcoatingshavebettercorrosi

onresistanceinh2so4，hcl，h3po4andfecl3solutioatas-depositedorheattreatment，andtheircorrosionresistanceissuperiortothatof316lstainlesteel；thecorrosionresistanceofni-w-p-siccoatinginhcl，h2so4andfecl3solutioismuchbetterthanthatofni-w-pandre-ni-w-p-siccoatings；however，thecorrosionresistanceofthere-ni-w-p-siccompositeinh3po4solutionissuperiortothatofni-w-p-sicandni-w-pcoatings.thecorrosionmechanismofre-ni

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