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《基于激光重熔niti冷噴涂涂層的組織性能分析》由會(huì)員上傳分享,免費(fèi)在線(xiàn)閱讀,更多相關(guān)內(nèi)容在學(xué)術(shù)論文-天天文庫(kù)。
1、論文題目:基于激光重熔Ngri冷噴涂涂層的組織性能研究專(zhuān)業(yè):材料加工工程碩士生:張娜(簽名)指導(dǎo)老師:周勇(簽名)汲塑,、摘要本文利用機(jī)械合金化技術(shù)制備適合于冷噴涂使用的Ni/Ti合金粉末;在普通的1Crl8Ni9Ti不銹鋼基體上采用不同的工藝參數(shù)獲得Ni/Ti冷噴涂涂層,并對(duì)所制涂層進(jìn)行激光重熔強(qiáng)化處理。采用XRD、SEM和EDS等分析手段對(duì)合金粉末、重熔前后涂層組織結(jié)構(gòu)及微觀特征進(jìn)行了分析和表征,在對(duì)Ni/Ti合金涂層性能分析研究時(shí),重點(diǎn)研究了Ni/Ti合金涂層的抗空蝕性能。實(shí)驗(yàn)結(jié)果顯示:冷噴涂層由扁平狀顆粒沉積而成
2、,并且移植了粉末顆粒的組織結(jié)構(gòu),具有明顯層狀結(jié)構(gòu);冷噴涂過(guò)程中Ni、Ti顆粒未發(fā)生明顯的氧化和相變。經(jīng)過(guò)激光重熔處理的Ni/Ti冷噴涂涂層發(fā)生相變,重熔層主要成分為B2結(jié)構(gòu)和B19結(jié)構(gòu)的NiTi金屬間化合物,組織非常致密均勻且具有明顯的區(qū)域特征;用顯微硬度儀測(cè)量了基體及重熔前后涂層顯微硬度,試驗(yàn)測(cè)得重熔層具有最高的顯微硬度,未處理NYTi涂層表面平均硬度為525.1HV0.3,且波動(dòng)較大;重熔層表面硬度平均值為827.3HV0.3,比原冷噴涂涂層提高約57.6%。利用超聲波振動(dòng)空蝕設(shè)備測(cè)試Ni/Ti涂層的抗空蝕性能,發(fā)現(xiàn)
3、激光重熔后涂層在相同條件下,具有最小的空蝕失重量;其空蝕穩(wěn)定性較未處理涂層和基體分別提高了4倍和7倍,平均失重率為2.56mg/h。通過(guò)對(duì)比研究發(fā)現(xiàn),激光重熔處理對(duì)Ni/Ti冷噴涂涂層起到性能優(yōu)化的作用。關(guān)鍵詞:NUTi涂層;機(jī)械合金化;冷噴涂;激光重熔;空蝕論文類(lèi)型:應(yīng)用研究‘d..英文摘要Subiect:ResearchontheMicrostructureandpropertiesofNi/TiColdSprayingCoatingbyLaserRemeltingSpeciality:MaterialProcess
4、ingEngineeringName:ZhangNa(signature)Instructor:ZhouYong(signature)ABSTRACTThispaperusedthetechnologyofmechanicalalloyingtopreparationoftheNi/Tialloypowderwhichissuitableforcoldspraying.TheNi/Ticoldsprayingcoatingsonthe1Crl8Ni9Tistainlesssteelsubstratewereobtaine
5、dusingdifferentprocessparametersandthecoatingwereremeltedbylasertreatment.SEM,EDSandXRDtechnologieswereusedtostudythemicrostructureoftheNi/Ticoatingbycoldsprayingandlaserremelting.CavitationerosionisoneoftheimportantperformancesofNi/Tialloycoming,Itwasfocusontoan
6、alysisandstudy.Theresultshowsthatthecoldspraycomingsdepositedwithflatparticlesandremainedlayeredstructureofpowderparticles.NiandTiparticlesinthecoatingsbycoldsprayingwerenotoxidizedandalloyed.Thephaseoflaserremeltingcoatinghaschanged.Themainmicrostructureofcoatin
7、gbylaserremeltingisNiTiintermetalliccompoundwhichincludedB2andB19.Theremeltedcoatingmicrostructureisverydenseandhasobviousregionalcharacteristic.Theaveragemicro—hardnessofcoatingbylaserremeltingis827.3HV0.3whichishigherthanthatofsubstrateandNi/Ticoatingbycoldspra
8、ying.Theremeltedcoating’Shardnessisincreasedabout57.6%ofcoldsprayedcoatingthatis525.1HV0.3.Ni/Ticoatingcavitationresistancewastestedusingultrasonicvibrationcav