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1、第18卷第1期材料科學(xué)與工藝Vol.18No.12010年2月MATERIALSSCIENCE&TECHNOLOGYFeb.,2010脈沖電沉積工藝對鎳鍍層結(jié)構(gòu)與硬度的影響1,32333王玉,袁學(xué)韜,俞宏英,孫冬柏,李輝勤(1.中國文化遺產(chǎn)研究院,北京100029,ywang03@163.com;2.北京有色金屬研究總院,北京100088;3.北京科技大學(xué)材料科學(xué)與工程學(xué)院,北京100083)摘要:為了優(yōu)化脈沖電鍍鎳工藝,采用掃描電子顯微鏡、X射線衍射儀和顯微硬度儀研究了脈寬、脈間、峰電流密度對
2、鍍層的晶粒尺寸、表面形貌、晶體取向和硬度的影響.結(jié)果表明,保持峰電流密度和脈間不變,鍍層的晶粒尺寸隨著脈寬的增加先減小后增加.當(dāng)脈寬由0.1ms增至8ms,晶體取向由(111)織構(gòu)向(200)織構(gòu)轉(zhuǎn)變.保持峰電流密度和脈寬不變,當(dāng)脈間的增加,晶粒尺寸增大,但晶體的取向不變.增加峰電流密度能22夠顯著降低鍍層的晶粒尺寸.當(dāng)峰電流密度由0.2A/cm增至2.0A/cm,晶體取向由隨機(jī)態(tài)向強(qiáng)的(200)織構(gòu)轉(zhuǎn)變.鍍層的硬度與鍍層的晶粒尺寸有關(guān),晶粒尺寸較大時,服從Hall-Petch關(guān)系,晶粒尺寸較小
3、時,產(chǎn)生納米效應(yīng),反Hall-Petch關(guān)系.因此,脈寬、脈間、峰電流密度均能顯著影響鍍層的顯微硬度.關(guān)鍵詞:脈沖電沉積;微觀結(jié)構(gòu);納米效應(yīng)中圖分類號:TQ153文獻(xiàn)標(biāo)識碼:A文章編號:1005-0299(2010)01-0089-07Influenceofpulseparametersonthemicrostructureandmicrohardnessofnickelelectrodeposits1,32333WANGYu,YUANXue-tao,YUHong-ying,SUNDong-ba
4、i,LIHui-qin(1.ChineseAcademyofCulturalHeritage,Beijing100029,China,ywang03@163.com;2.GeneralResearchInstituteforNon-ferrousMetals,Beijing100088,China;3.SchoolofMaterialsScienceandEngineering,UniversityofScienceandTechnologyBeijing,Beijing100083,China
5、)Abstract:Tooptimizethenickelpulseplatingprocess,thescanningelectronmicroscope,X-raydiffractionandmicrohardnesstesterwereusedtodeterminetheinfluenceofpulseon-time,pulseoff-timeandpeakcur-rentdensityonthegrainsize,surfacemorphology,crystalorientationa
6、ndmicrohardnessofthenickelelectro-deposits.Thestudyshowsthatatconstantoff-timeandpeakcurrentdensity,thecrystalsizeofthedepositsin-itiallydecreasesandthenstartstoincreasewiththeincreasingpulseon-time.Thecrystalorientationprogres-sivelychangesfroma(111
7、)textureattheon-timeof0.1mstoastrong(200)textureattheon-timeof8ms.Theincreaseofpulseoff-timeattheconstanton-timeandpeakcurrentdensityresultsinaprogressiveincreaseincrystalsize,whilethecrystalorientationremainsunaffected.Theincreaseofpeakcurrentdensit
8、yresultsinconsiderablerefinementincrystalsizeofthedeposits.Thecrystalorientationprogressivelychangesfromanal-2mostrandomdistributionatthelowestpeakcurrentdensityof0.2A/cmtoastrong(200)textureatthepeak2currentdensityof2.0A/cm.Themicrohardnessofdeposit