在壓敏電阻氧化鋅-氧化銅內(nèi)中添加氧化鉻, 氧化鉍, 氧化鎳對顯微結(jié)構(gòu)與電流-電壓特性的改變

1、ResearchResearchArticleArticle研究報告研究報告MicrostructureMicrostructureCurrentvoltageCurrentvoltageacteristicsacteristicsofof(ZnO(ZnOCuO)CuO)VaristVaristSystemSystemininthethePresencePresenceofofAdditiveAdditiveOxidesOxidesCr

2、Cr2O3BiBi2O3NiONiO在壓敏電阻氧化鋅在壓敏電阻氧化鋅氧化銅內(nèi)中添加氧化鉻氧化銅內(nèi)中添加氧化鉻氧化鉍氧化鉍氧化鎳對顯微結(jié)構(gòu)與電流氧化鎳對顯微結(jié)構(gòu)與電流電壓特性的改變電壓特性的改變S.E.MansourO.A.DesoukyS.M.NegimW.A.Kamil作者：馬來西亞聖英大學作者：馬來西亞聖英大學(University(UniversitySainsSainsMalaysiaMalaysia)翻譯：晟銘電子翻譯：晟銘電

3、子技術(shù)長技術(shù)長Accepted:Accepted:November142010Published:Published:April222011INTRODUCTIONINTRODUCTION簡介簡介Varistsarematerialswithnonlinearcurrentvoltageacteristics.Theyareusedbothasprotectingdevicesagainstovervoltagesinelectroni

4、cindustrialequipmentsassurgearrests(Souzaetal.2003).CommercialvaristsusedinprotectionsystemsarebasedonSiC(siliconcarbide)ZnO(zincoxide).SiCbasedvaristshavelownonlinearitycoefficients(α=5)whereαisthenonlinearityconstantde

5、finedbytherelation:I=KVαwhereIiscurrentVisvoltageKisaproptionalityconstant(Skuratovskyetal.2004).TheZnObasedvaristshaveveryhighnonlinearitycoefficients(α=50)theirmajphasecontains(besidesZnO)smallamountsofBi2O3Sb2O3CoOMnO

6、2Cr2O3(Tongetal.2009Wuetal.2010).ThereactionbetweentheZnOtheadditivesathightemperaturesleadstothefmationofseveralphasesattheZnOgrainboundaries(Peiteadoetal.2005).Thusdespitetheirchemicalcompositionphasestheprocessingmeth

7、odaswellasthesinteringtemperatureheatingcoolingratesinfluencetheelectricalpropertiesoftheseceramicsfundamentally(Linetal.2007).Inviewofthisfacttheliteraturecontainsextensivereptsdescribingtheinfluenceofprocessingvariable

8、sonthepropertiesmechanismsthatgovernthesesystemproperties(BernikDaneu2007Ottetal.2001Congetal.2007SoThenonlinearityindex(α)wascalculatedinacurrentrangeof1mAto1Ausingthefollowingequation:非線性係數(shù)(α)的獲得來自一個電流範圍由1mA~1A使用下列方程式w

9、hereI1I2arethecurrentsatthevoltagesV1V2.I1和I2是不同電壓V1和V2輸下的電流值。ThephasecompositionofthesampleswasanalyzedbyXraydiffraction(XRD)usingCuKαradiationonapowerdiffractometer(Philipsapparatustype170).Samplesfmicrostructureanalys

10、iswerepolishedontheplanesurfacewithcarbundumpaperofdifferentgrades3006001000followedgradesofdiamondpaste72.51micron.Thesampleswerethenthoughlywashedinanultrasonicbathfhalfanhour.Thepolishedsampleswereetchedin5%diluteHCls

11、olutionf5sec.MicrostructuredevelopedwasexaminedunderSEMtypePhilipsXL30providedwithEDAXaftersputteringwithgold.試片中的組成相由X光繞射分析儀使用銅靶繞射分析儀分析。顯微結(jié)構(gòu)部份則以碳化矽砂紙按照300#600#與1000#磨平後，以鑽石膏7um2.5um和1um依序拋亮。並且以超音波清洗半小時，然後以鹽酸溶液腐蝕5秒鐘所獲得。顯

12、微結(jié)構(gòu)的觀察以帶有成份分析的電子掃描式顯微鏡觀察，試片表面需要先鍍金。RESULTRESULT結(jié)果結(jié)果Sinterabilityofthesuggestedmixesisdeucedfromtheresultsofphysicalpropertiesintermsofwaterabsptionapparentpositybulkdensityfiringshrinkage.Resultsoffiringshrinkagebulkdens

13、ityshowedanincreasewithriseintemperature.Maximumvaluesoffiringshrinkagewereattainedinspecimensfiredat1200Cf2h.Firingthespecimensmethan1100Cf2hcausedthestartofdefmationofthedifferentmixes.Therefeitisnotrecommendedtoincrea

14、sethetemperaturemethan1100Castheincreaseinbulkdensitydisplayedtheredidnotshowremarkablechangewithincreasingtemperature.這樣混合試片的燒結(jié)性表現(xiàn)以吸水率孔隙率試體密度和燒結(jié)收縮率等物理性質(zhì)的量測結(jié)果來評估。觀察燒結(jié)收縮率和試體密度的結(jié)果表明：燒結(jié)溫度上升會增加這兩個數(shù)值，燒結(jié)收縮達到最大值是在1200C2小時持溫的時候。