Txawm tias stainless hlau cua sov daim hlau tuaj yeem corrode thaum raug cov kua qaub, ntsev, lossis tshuaj ntxuav. Kev kho deg muab kev tiv thaiv kev tiv thaiv uas txuas ntxiv lub phaj lub neej kev pab cuam nyob rau hauv ib puag ncig nruj thaum tswj kev ua haujlwm thermal. Xaiv qhov tsim nyogcorrosion resistant cua sov phaj nto khoyuav tsum muaj kev nkag siab txog kev raug tshuaj lom neeg, kev ua haujlwm kub, kev siv tshuab, thiab cov nqi txwv. Phau ntawv qhia no piv cov txheej txheem ntau tshaj plaws -PTFE, electroless npib tsib xee, nyuaj chrome, thiab ceramic- thiab muab cov txheej txheem xaiv rau cov phaj cua sov.
Vim li cas cov kev kho deg yog siv rau cov cua sov phaj
Cov phaj cua sov feem ntau yog tsim los ntawm txhuas, hlau, lossis stainless hlau. Thaum cov hlau tsis muaj steel muaj kev tiv thaiv corrosion, nws raug tawm tsam los ntawm chlorides (xws li, tshuaj tsuag ntsev, tshuaj dawb), muaj zog txo cov kua qaub, thiab qee cov tshuaj ntxuav. Aluminium yog qhov yooj yim rau alkalis thiab acids. Kev kho deg ua haujlwm rau ntau lub hom phiaj:
Tshuaj tiv thaiv- Cais lub hauv paus hlau los ntawm cov txheej txheem corrosive kua, vapors, los yog tshuaj ntxuav.
Cov khoom tsis yog-stick- Tiv thaiv kom kho cov resins, cov nplaum, lossis cov khoom noj khoom haus los ntawm kev ua raws li lub phaj.
Hnav tsis kam- Tiv thaiv lub phaj saum npoo los ntawm kev puas tsuaj thaum thauj khoom, tu, lossis tiv tauj nrog cov khoom.
Dielectric rwb thaiv tsev- Tiv thaiv hluav taws xob conduction ntawm lub phaj thiab cov khoom rhiab heev (piv txwv li, semiconductor wafers).
Qhov kev xaiv ntawm txheej yog nyob ntawm qhov kev hem thawj tseem ceeb thiab cov phaj kev ua haujlwm.
Kev sib piv ntawm Cov Kev Kho Kom Zoo Tshaj Plaws
Cov lus hauv qab no qhia txog cov yam ntxwv tseem ceeb ntawm plaub qhov kev kho mob thawj zaug uas siv rau corrosion-cov pa hluav taws kub tiv taus.
| Txheej hom | Max Nruam Temp (degree) | Corrosion Resistance | Hardness (HRC sib npaug) | Tus nqi txheeb ze (ib m²) | Hom Thickness |
|---|---|---|---|---|---|
| PTFE (fluoropolymer) | 260 | Zoo heev (wide chemical range) | Mos (~R 110 Ntug D) | Siab | 0.3-0.8 hli |
| Electroless npib tsib xee (EN) | 400 (nrog diffusion) | Nruab Nrab - Zoo (tiv taus ntau cov kua qaub, tsis muaj zog oxidizers) | ~ 50 HRC | Tsawg – Nruab Nrab | 25–75 µm |
| Hard chrome | 400 | Nruab nrab (porous, yuav tsum tau sealant) | ~ 70 HRC | Nruab nrab | 50–250 µm |
| Ceramic (Al₂O₃, plasma spray) | 800+ | Zoo heev (tshwj tsis yog muaj zog alkalis) | ~ 60-70 HRC | Siab | 100–500 µm |
1. PTFE (Polytetrafluoroethylene) Txheej
PTFE, feem ntau raug xa mus los ntawm lub npe Teflon®, yog ib qho fluoropolymer dav siv rau nws tshwj xeeb tshuaj inertness thiab tsis yog - nplaum nto. Rau cov phaj cua sov, PTFE yog siv los ua cov kua dispersion los yog hmoov uas yog txau rau ntawm cov hlau nto thiab tom qab ntawd kho ntawm qhov kub thiab txias (feem ntau 370-400 degree).
Qhov zoo:
Tiv thaiv yuav luag txhua yam tshuaj, suav nrog cov kua qaub uas muaj zog (hydrochloric, sulfuric, nitric), bases, hnyav, thiab oxidizers.
Tsis yog - cov khoom nplaum tiv thaiv cov khoom adhesion - zoo tagnrho rau resin curing, ua zaub mov, thiab tuav tuav.
Tsawg coefficient ntawm kev sib txhuam (0.05-0.10) txo qhov hnav ntawm zawv zawg qhov chaw.
Zoo dielectric zog (kwv yees li 20 kV / mm).
Kev txwv:
Qhov ntsuas kub tsis tu ncua yog kwv yees li 260 degree. saum toj no, PTFE degrades thiab tso tawm cov pa phem.
Mos nto - yooj yim khawb los yog abraded los ntawm cov khoom ntse lossis cov khoom tawv.
adhesion tsis zoo rau hlau; yuav tsum tau ib txheej primer (feem ntau PFA los yog FEP) thiab ua tib zoo npaj nto.
Thicker coatings txo thermal conductivity me ntsis (tab sis negligible rau feem ntau daim ntawv thov).
Daim ntawv thov:
PTFE txheej thickness ntawm cov khoom cua sov phaj feem ntau yog 0.3-0.8 hli. Ntau lub tsho tiv no yog siv los ua kom tiav cov pinhole- pub dawb. Nws yog ib qho tseem ceeb kom tsis txhob muaj kev puas tsuaj rau txhua yam; PTFE coated exposes lub hauv paus hlau, tso cai rau undercutting corrosion mus propagated.
2. Electroless Nickel (EN) Plating
Electroless npib tsib xee yog tso los ntawm cov tshuaj autocatalytic tshuaj tiv thaiv, ua ib txheej txheej txawm nyob rau hauv complex geometries nrog rau hauv lub qhov los yog qhov muag tsis pom kab noj hniav. Cov txheej yog npib tsib xee-phosphorus alloy (feem ntau 6-12% P). Rau cov phaj cua sov, siab -phosphorus EN (10–12% P) yog qhov zoo dua rau kev tiv thaiv corrosion ntau tshaj.
Qhov zoo:
Exceptional uniformity - thickness variation thoob plaws lub phaj loj yog feem ntau tsawg dua ± 10%.
Nruab nrab rau zoo corrosion kuj - resists ntau acids (xws li, dilute sulfuric, acetic), alkalis, thiab ntsev tov. Tsis muaj zog oxidizers zoo li nitric acid lossis ferric chloride.
Hardness ntawm kwv yees li 50 HRC raws li - tso nyiaj; tuaj yeem ua cua sov-kho rau 65-70 HRC (txawm tias qhov no txo qis kev tiv thaiv corrosion).
Zoo adhesion rau hlau, aluminium, thiab tooj liab alloys.
Nqi -zoo rau nruab nrab- mus rau - daim hlau loj.
Kev txwv:
Tsis muaj tshuaj tiv thaiv zoo li PTFE lossis siab -kawg ceramics. EN tuaj yeem pinhole lossis tawg nyob rau hauv thermal cycling yog tias tsis siv zoo.
Qhov kub siab tshaj plaws nyob ib puag ncig 400℃rau lub sijhawm luv luv; Lub sij hawm raug tshaj 300℃tuaj yeem ua rau crystallization thiab embrittlement.
Hluav taws xob conductivity - tsis haum raws li ib tug dielectric (tuaj yeem ua kom zoo dua rau hauv av, tsis zoo rau rwb thaiv tsev).
Daim ntawv thov:
Electroless npib tsib xee feem ntau tau teev tseg rau cov phaj cua sov siv hauv cov khoom siv hluav taws xob lossis cov khoom siv kho mob tsim khoom uas yuav tsum tau tswj kom nruj qhov ntev. Lub thickness ntawm txheej yog li ntawm 25 mus rau 75 µm. Ib qho kev tshaj tawm -plating kev kho cua sov (xws li, 200℃rau 2 teev) txhim kho adhesion thiab txo cov hydrogen embrittlement.
3. Hard Chrome Plating
Hard chrome (tseem hu ua industrial chrome) yog txheej txheej electrolytically tso chromium. Nws muaj nuj nqis rau qhov hnyav hnyav thiab hnav tsis kam. Rau cov cua sov phaj, tawv chrome yog siv rau cov hlau los yog stainless hlau substrates.
Qhov zoo:
High hardness (65-70 HRC) - tiv thaiv khawb, galling, thiab abrasive hnav.
Tsawg coefficient ntawm kev sib txhuam (0.15-0.20).
Zoo thermal conductivity (chrome yog ~ 90 W / m·K, ze rau hlau).
Kev kub siab muaj peev xwm (txog 400℃tsis muaj degradation).
Kev txwv:
Inherently ntxeem tau. Cov txheej chrome muaj micro- tawg uas tuaj yeem tso cov kua dej corrosive mus txog lub hauv paus hlau. Lub sealant (piv txwv li, roj lossis polymeric sealer) yuav tsum muaj rau kev tiv thaiv corrosion.
Nruab nrab corrosion kuj - ua tau zoo nyob rau hauv ib puag ncig me me tab sis tsis muaj zog acids lossis chlorides.
Kev txhawj xeeb ib puag ncig - hexavalent chromium yog tshuaj lom; plating yuav tsum tau tso cai tshwj xeeb thiab kho cov khib nyiab.
Tsis sib xws; txhim kho- nce ntawm ntug (dub- pob txha) yuav tsum tau tshaj tawm - sib tsoo.
Daim ntawv thov:
Hard chrome tau teev tseg rau siab - cov phaj siab lamination lossis txhua daim ntawv thov uas siv tshuab yog qhov kev hem thawj thiab corrosion yog theem nrab. Thickness ntawm 50-250 µm yog feem ntau. Tom qab plating, qhov saum npoo feem ntau yog av tiaj tus kom ua tiav qhov yuav tsum tau ua kom haum. Kev kho kev sib khi (piv txwv li, immersion hauv corrosion-inhibiting roj) yog siv ua ntej lub phaj muab tso rau hauv kev pabcuam.
4. Ceramic Coatings (Aluminium Oxide, Plasma Spray)
Cov txheej txheem ceramic yog siv los ntawm cov txheej txheem tshuaj tsuag thermal (plasma lossis HVOF). Cov khoom siv hauv cov khoom siv hmoov hmoov- feem ntau yog txhuas oxide (Al₂O₃) los yog chromium oxide (Cr₂O₃)- yog yaj thiab nrawm rau ntawm lub phaj phaj, tsim ib txheej ntom ntom ntom ntom.
Qhov zoo:
Muaj peev xwm kub heev - txog li 800℃lossis siab dua.
Cov tshuaj tiv thaiv zoo heev - Al₂O₃ resists feem ntau cov kua qaub, alkalis, thiab cov kuab tshuaj (tshwj tsis yog muaj zog hydrofluoric acid thiab kub concentrated alkalis).
High dielectric zog - muab hluav taws xob rwb thaiv tsev ntawm lub phaj thiab ib feem.
Zoo hardness (60-70 HRC sib npaug) thiab hnav tsis kam.
Kev txwv:
Brittle - susceptible rau cracking nyob rau hauv kev cuam tshuam los yog thermal shock. Cracks nthuav tawm lub hauv paus hlau.
Yuav tsum tau npaj qhov ntxhib nto (grit blasting) rau adhesion, uas tej zaum yuav tsis haum rau kev nplua - tiav daim ntawv thov.
Cov tuab tuab (100-500 µm) thiab tuaj yeem cuam tshuam rau qhov ntev ntev.
Tus nqi siab dua li electroless nickel lossis hard chrome.
Daim ntawv thov:
Ceramic coatings yog siv rau cov cua sov phaj rau siab -kub iav molding, semiconductor wafer ua (qhov twg hluav taws xob cais yog ib qho tseem ceeb), thiab aggressive tshuaj ib puag ncig saum 260℃(tshaj PTFE qhov txwv). Ib txheej txheej ceramic (piv txwv li, impregnated nrog polymer) tuaj yeem txo qhov porosity thiab txhim kho corrosion kuj.
Cov Txheej Txheem Xaiv: Sib piv cov txheej rau daim ntawv thov
Qhov kev xaiv ntawm acorrosion resistant cua sov phaj nto khoyog coj los ntawm plaub yam tseem ceeb.
Tshuaj Tiv Thaiv
| Chemical Ib puag ncig | Pom zoo Txheej | Tsis pom zoo |
|---|---|---|
| Muaj zog acids (HCl, H₂SO₄, HNO₃) | PTFE, Ceramic | Electroless npib tsib xee, Hard chrome |
| Muaj zog alkalis (NaOH, KOH) | PTFE, Hard chrome (sealed) | Ceramic (tawm los ntawm kub alkalis), EN |
| Tshuaj tsuag ntsev (NaCl, marine ib puag ncig) | PTFE, Electroless npib tsib xee | Hard chrome (unsealed) |
| Organic kuab tshuaj (acetone, cawv) | Txhua yam ua kom txaus | – |
| Oxidizing neeg sawv cev (bleach, peroxides) | PTFE, Ceramic | Electroless nickel (qhov) |
Ua haujlwm kub
Hauv qab 260 degree- PTFE muaj cov tshuaj tiv thaiv zoo tshaj plaws thiab tsis yog - cov khoom nplaum.
260-400 degree- Electroless npib tsib xee lossis tawv chrome (nrog cov sealants tsim nyog) yog tsim nyog. Ceramic kuj ua haujlwm tab sis kim dua.
Tshaj 400 degree- Tsuas yog cov txheej txheem ceramic (lossis cov hlau tsis muaj hlau tsis muaj hlau tshwj xeeb) tuaj yeem muaj sia nyob.
Mechanical Wear thiab Abrasion
High hnav (sliding qhov chaw, abrasive tu)- Hard chrome lossis ceramic.
Tsawg hnav (static phaj, maj mam so)- PTFE lossis electroless npib tsib xee.
Thermal Cycling thiab Mechanical Stress
Nquag thermal cycles (20℃txog 200℃thiab rov qab)- PTFE thiab electroless npib tsib xee zam kev caij tsheb kauj vab. Hard chrome tuaj yeem tawg yog tias lub substrate nthuav dav (piv txwv li, txhuas hauv chrome - tsis pom zoo). Ceramic yog qhov siab tshaj ntawm thermal shock tshwj tsis yog siv cov tuab tuab ntawm qhov sib txuam -expansion substrate (piv txwv li, ceramic ntawm Invar).
Kev txiav txim siab nqi
Electroless npib tsib xee yog tus nqi tshaj plaws - siv tau rau kev tiv thaiv corrosion nruab nrab. PTFE yog siab dua vim ntau txheej txheej thiab primer yuav tsum tau. Hard chrome nqi sib txawv nrog thickness thiab ncej- sib tsoo. Ceramic spray feem ntau yog kim tshaj plaws vim yog cov cuab yeej tshwj xeeb thiab cov nqi tso nyiaj tsawg.
Cov Tswv Yim Qhia Txog Kev Qhia Txog Txheej Txheej
Thaum sau cov lus qhia tshwj xeeb rau corrosion-cov phaj cua sov, cov ntsiab lus hauv qab no yuav tsum suav nrog:
Cov khoom siv substrate-Aluminium, hlau, lossis stainless hlau. Aluminium yuav tsum tau tshwj xeeb pretreatment (zincate los yog anodize) ua ntej electroless nickel los yog PTFE.
Txheej hom thiab thickness- Piv txwv li, "PTFE txheej, 0.5 hli nominal thickness, pinhole -dawb ib ASTM D714."
Corrosion xeem yuav tsum tau- Piv txwv li, "48 teev ntsev tsuag ib ASTM B117 tsis muaj xeb liab."
Kev ntsuas kub- "Kev ua haujlwm tsis tu ncua ntawm 200 degree, cuam tshuam rau 250 degree."
Flatness tom qab txheej- "Coated nto flatness yuav tsum tsis pub tshaj 0.05 hli tshaj 300 hli."
Ntug thiab qhov kev pab cuam- "Tag nrho cov npoo thiab dhau los ntawm - qhov yuav tsum tau coated nrog tsis muaj cov substrate raug."
Nyob rau hauv ib puag ncig corrosive, nws yog ib qho tseem ceeb kom sib npaug tshuaj tiv thaiv nrog cov neeg kho tshuab durability. PTFE- cov phaj coated uas niaj zaus txhuam nrog cov ntaub nplaum yuav ua tsis tau sai. Hloov pauv, lub phaj nyuaj chrome hauv lub da dej muaj zog acid yuav ua rau nws cov micro- tawg hauv lub lis piam.
Xaus
Cov kev kho deg ua rau nthuav dav lub hnab ntawv ua haujlwm ntawm cov hlau hlau cua sov. PTFE coatings muab cov tshuaj tsis sib haum xeeb thiab tsis yog - nplaum ua haujlwm txog 260℃. Electroless npib tsib xee muab cov khoom sib xws, tus nqi - tiv thaiv zoo rau qhov nruab nrab corrosion ib puag ncig. Hard chrome plating muab qhov hnyav hnyav tab sis yuav tsum tau muab khi rau kev tiv thaiv corrosion. Ceramic coatings ua rau siab -kub thiab siab - dielectric daim ntaub ntawv. Kev xaiv ntawm acorrosion resistant cua sov phaj nto khoyuav tsum xav txog qhov tshwj xeeb raug tshuaj, qhov kub thiab txias, kev hnav khaub ncaws, thiab thermal cycling tej yam kev mob. Cov khoom siv tiv thaiv yog ib feem tseem ceeb ntawm kev tsim lub tshuab cua sov; txoj kev kho saum npoo kom raug ncua kev pab cuam lub neej, txo kev sib kis, thiab ua kom zoo thermal ua haujlwm zoo hauv kev ua haujlwm hnyav.
