Chromium Films Thiab Chromium Nitride Films
Jan 05, 2018| Chromium films
Nyuaj chromium coatings tau nyob ib ncig ntev ntev thiab yuav siv tau los txhim khu thiab txhuam cov cuab yeej thiab cov khoom siv cav, xws li piston rings, hydraulic cylinders, thiab pwm. Cov yeeb yaj kiab uas nyias nyias chromium films feem ntau siv rau cov laj thawj zoo hauv lub tsheb los yog kev lag luam. Lwm hom ntawm chromium yog chrome-rau-iav qhov ncauj qhov ntswg rau photolithography nyob rau hauv kev lag luam microelectronics. Cov kab dej tshuaj cog rau Cr yog chromium plating, ib txoj kab uas ntub dej electrolytic. Txawm li cas los no txoj kev siv hexavalent chromium uas yog carcinogenic thiab nws yog vim li ntawd tsim nyog los hloov nws los ntawm kev noj qab haus huv thiab ib puag ncig tus phooj ywg cov txheej txheem, piv txwv li ib qho PVD. Cov tshuaj cog qoob los yog cathodic evaporated Cr, CrN, thiab CrC, tab sis kuj chromium dawb coatings li pob zeb diamond zoo li (DLC), yog suav tias yog hloov tau rau electroplated nyuaj chromium coatings nyob rau hauv loj teev muaj kev siv.
Lub tshuab raj ntawm chromium yog qeeb heev. Nyob rau hauv magnetron sputtered Cr / CrN thiab Cr / Cr 2 N multilayer coatings lub chromium txheej yog sputtered los ntawm ib tug φ150 mm magnetron ntawm tus nqi ntawm 10 μm / h (≈170 nm / min) mus rau-20V biased steel substrates ntawm lub hom phiaj ntawm 4 A (≈ 23 mA / cm 2).
Txoj kev loj hlob ntawm kev ntxhib los mos hauv RF sputtered Cr films yog tham nyob rau hauv ib qho haujlwm ntawm Feng et al. qhov twg yog ib qho qauv raws li qhov kev txo qis thiab cov hluav taws xob interfacial. Cov qauv raug kuaj hauv Cr depositions ntawm iav substrates ntawm cov neeg mob txawv. Cov yeeb yaj kiab ib txwm muaj Cr (110) zoo nkauj thaum tso rau iav substrates tom chav tsev kub tab sis thaum preheated rau 250 ° C (110) lossis (002) kev ntxhib los mos tau txiav txim los ntawm tus nqi ntawm cov zog tso los ntawm Ar ions los yog Cr atoms. Cr (110) qhov kev taw qhia tau zoo tshaj plaws los ntawm kev sib tsoo ntawm cov iav substrate. Kev tswj ntawm qhov kev taw qhia dua yog ib qho tseem ceeb xws li thaum Cr Films yog siv los ua ib qho hauv qab rau cobalt-raws li cov yeeb yaj duab magnetic, qhov twg yog qhov Cr (200) kev ntxhib los mos.
Chromium nitride films
Chromium nitride films muaj zoo heev corrosion thiab hnav cov khoom thiab lub siab thermal stability. Nws yog tau deposit tuab (ob peb 10 μm) CrN films tsaug cov nplua grained thiab ib cov qauv siab tsis tshua muaj. Qhov tseeb no nrog CrN tsawg dua li TiN, tiam sis tseem nyuaj heev, ua rau CrN yuav haum rau kev tiv thaiv saum npoo ntawm cov thooj muag me me xws li txhuas aluminium thiab cov hlau tsis huv. Lub adhesion rau hlau yog feem ntau zoo tab sis nws muaj peev xwm yuav kho kom zoo los ntawm ib qho Intermediate Cr-layer. Stoichiometric los yog ze-stoichiometric CrN coatings muaj cubic NaCl-kev. Nrog rau cov ntsiab lus uas tsis muaj nitrogen cov nyhuv hla Cr 2 N theem yuav tshwm tuaj. Chromium yog ib qho reactive hlau dua titanium thiab qhov no muaj kev rau txim rau reactive PVD. Qhov yuav tsum tau muaj nitrogen ib nrab ntawm daim qauv stoichiometric CrN films yog siab dua rau stoichiometric TiN. Qee cov khoom ntawm kev lag luam muaj txheej txheem yog ib qho nyuaj ntawm 1750 HV thiab thermal stability txog 700 ° C.
Lub siab thermal stability ua CrN-coatings heev haum rau hnav thiab kev tiv thaiv kev tiv thaiv hauv kev ua hauj lwm kev kub ceev, xws li tuag casting hauv siab. Piv txwv ntawm CrN coated Cheebtsam yog pwm yas, extrusion tuag, thiab cov cuab yeej rau kev ua haujlwm thiab txias txoj hauv cov hlau ua Cu thiab Ti.
Cov hom txheej txheem ntau rau CrN films yog cov pob zeb ntub magnetron pluttering thiab arc evaporation. Lub DC magnetron sputtering tau siv los tshawb xyuas cov nyhuv ntawm cov qauv kev nyiam dua ntawm cov khoom siv cuab yeej ntawm CrN coatings. Ob coatings tau ua rau tag nrho siab ntawm 0.27 pa (2 mTorr), lub hom phiaj tam sim no ntawm 2.5 A, OEM tswj N 2 ndlwg, thiab nyob rau hauv DC sib txawv voltage a) 70 V thiab b) 120 V. Tus nqi tso tawm yog ~ 18 thiab ~ 28 nm / min feem. Cov films uas tau tshwm sim yog ib tug) CrN nrog ib tus qauv ntawm kev nyiam dua (200), tus qauv columnar thiab ib cov tawv nqaij ntawm 2300 HV thiab b) Cr 2 N nrog ib qho kev taw qhia dua ntawm (111), qauv ntom ntsa thiab muaj zog me ntsis (2400 HV) tab sis nrog ib qho weaker adhesion rau hlau (SKD11) substrates.
Lub siab tso tawm ntawm CrN x los ntawm DC magnetron sputtering nrog ib qho kev nyuaj siab nyiaj DC yog kawm los ntawm Nam et al. Cov yeeb yaj kiab tau tawg hnyav nrog lub hom phiaj ntawm qhov sib txawv ntawm 13 W / cm 2 ntawm kev sib cav argone ntawm 0.24 Pa (1.8 mTorr) thiab muaj nitrogen ntws tawm ntawm 0 mus rau 45 sccm thiab muaj ntau qhov kev hloov siab. Qhov no ua rau nws ua tau kom tswj tau cov microstructure thiab theem sib xyaw ntawm CrN x films. Qhov siab tshaj plaws tus nqi kwv yees yog 210 nm / min rau Cr 2 N (89% ntawm tus nqi rau ntshiab Cr deposition) thiab lub siab tshaj plaws hardness yog 2250 kg / hli 2 (Knoop) rau ib theem mixed CrN + Cr. Tib pab pawg kuj tau ua ib qho kev tshawb nrhiav ntawm cov khoom ntawm CrN x films tso ntawm txawv deposition nqi. Nyob rau hauv txoj kev tshawb no lawv siv qhov kev ruaj siab ntawm qhov -100V thiab qhov kev ntsuas pa 0.2 ntawm 0.2 Pa (1.5 mTorr) thiab siv lub cim zog ntom nti 5, 10, thiab 13.2 W / cm 2 thiab cov nitrogen khiav ntau ntawm 0 txog 160 sccm. Lawv xaus lus tias cov nqi ntawm CRN nce linearly nrog lub hom phiaj hwjchim ntom (max 430 nm / min ntawm 13.2 W / cm 2 ) thiab hais tias kev nyuaj siab movie raug hloov ntawm tensile mus compressive nrog nce deposition tus nqi. Txuas ntxiv qhov nyuaj tshaj plaws thiab qhov zoo tshaj plaws adhesion tau pom nyob rau hauv zaj duab xis tso rau ntawm lub siab tshaj plaws lub zog fais fab vam tiv rau lub siab muaj kev nyuab siab thiab kev siab loj ntawm adatom.
Cov cuab yeej carbide coated nrog Cr x N y films los ntawm RF magnetron sputtering tau raug kuaj hauv wood machining. Rau cov qauv thiab tshuaj tsom cov duab tau muab tso rau Si substrates. Cov chaw nyob ntawm RF powers ntawm 450 W thiab 650 W thiab muaj ntau yam siab los ntawm 0.1 mus rau 1 Pa Lub sij hawm tso tawm tau xaiv ntawm 15 thiab 80 feeb nrog ib qhov siab tshaj qhov nqi ntawm 4.4 μm / h (73 nm / min) rau Cr 2 N. Tus Cr 2 N zaj duab xis tau muaj ib tus ncej txheem thaum lub CrN films seemed tsis muaj featureless nrog lub siab tshaj plaws ntawm 2100 HV. Cr 2 N cov yeeb yaj kiab tau pom tias tsis yooj yim, tiam sis tsis yeem tshaj qhov CrN films.
Ib qho tseem ceeb ntawm RF magnetron tau muab siv rau kev tshawb nrhiav ntawm CrN x films tso rau hauv qhov dav nitrogen ib nrab siab ntau ntawm 0.005 - 30 Pa qhov twg cov tshuaj thiab cov khoom siv dag zog tau tshawb xyuas. Lub zog ntawm lub hom phiaj tau khaws cia ntawm 300 W (lub hom phiaj ntawm lub hwj chim yog 6.8 W / cm 2 ) thiab Ar ib feem ntawm qhov siab ntawm 0.3 Pa Stoichiometric Cr 2 N tau txais rau nitrogen ib nrab qhov siab ntawm 0.02 thiab 0.04 Pa thiab ib qho stoichiometric CrN tau raug rau 0.3 Pa, thaum lub sij hawm rau lwm cov pressures lub CrN thiab Cr 2 N phaj raug tov. Qhov xaus yog tias cov ntsiab lus nitrogen hauv CrN x films yuav raug tswj los ntawm kev hloov cov nitrogen ib nrab siab, tab sis tsis tau ntawm nws tus nqi thiab qhov microstructure. Cov Cr 2 N films tau nyuab heev (27.1 GPa) thiab txhav (E = 348 GPa), ib theem xwb CrN yuav luag nyuab li Cr 2 N, tiam sis ntau dua elastic (E = 300 GPa) thiab cov nqi dej nqi qis dua.
Lub microstructure thiab cov khoom siv dag zog ntawm cov chromium nitride films tso rau ntawm kev kub ceev hlau substrates los ntawm cov hluav taws xob evaporation reactive yog kawm los ntawm Odén li al. 10 μm tuab films tau muab tso rau 220 feeb ntawm ib nrab ntawm 8 Pa thiab ib qho txawv tsis zoo substrate siab los ntawm 20 mus rau 400 V. Lub microstructure ntawm cov yeeb yaj kiab tau ntom thiab ncej, qhov kev taw qhia dua yog CrN (220) thiab CrN (220) kev ntxhib los kom zoo nkauj nrog kev nce siab tsis zoo siab txog 200V. Ib qho siab kawg nanohardness ntawm 29 GPa tau mus rau ib tug substrate bias ntawm -100 V.
Lub CrN coatings rau ib daim ntawv thov ua, txiav cov cuab yeej rau machining ntawm tooj liab, tau ua los ntawm ib lub cathodic arc ion plating. Cov duab no tau muab tso rau ntawm nitrogen ib nrab siab ntawm 4 Pa thiab txawv tsis zoo substrate biases, 0 - 200 V. Cov kev taw qhia dua yog CrN (111) thiab cov qauv micro yog ntom thiab columnar. Cov qoob loos tau tsawg dua nrog kev tsim kev phem thiab kev siab tshaj plaws Vickers micro hardness tau mus txog ib qho kev ntxub ntawm 100 V nrog rau qhov siab tshaj plaws kev ntsuaj siab. Kev ntsuam xyuas kev txiav txim siab txiav txim tau tias qhov nyuaj ntawm cov yeeb yaj kiab thiab qhov kev ntxhov siab seem tsis tuaj yeem raug coj los ua ib qho kev ntsuas ntawm qhov kev ua tau zoo hauv cov milling ntawm tooj liab.
